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Convert.ToSByte Metodo

Definizione

Converte un valore specificato in un intero con segno a 8 bit.

Overload

ToSByte(SByte)

Restituisce l'intero con segno a 8 bit specificato; non viene eseguita alcuna conversione effettiva.

ToSByte(String, Int32)

Converte la rappresentazione di stringa di un numero in una base specificata nell'intero con segno a 8 bit equivalente.

ToSByte(String, IFormatProvider)

Converte la rappresentazione di stringa specificata di un numero in un intero con segno a 8 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.

ToSByte(Object, IFormatProvider)

Converte il valore dell'oggetto specificato in un intero con segno a 8 bit mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.

ToSByte(UInt64)

Converte il valore dell'intero senza segno a 64 bit specificato in un intero con segno a 8 bit equivalente.

ToSByte(UInt32)

Converte il valore dell'intero senza segno a 32 bit specificato in un intero con segno a 8 bit equivalente.

ToSByte(String)

Converte la rappresentazione di stringa specificata di un numero in un intero con segno a 8 bit equivalente.

ToSByte(Single)

Converte il valore del numero a virgola mobile e con precisione singola specificato in un intero con segno a 8 bit equivalente.

ToSByte(Object)

Converte il valore dell'oggetto specificato in un intero con segno a 8 bit.

ToSByte(UInt16)

Converte il valore dell'intero senza segno a 16 bit specificato nell'intero con segno a 8 bit equivalente.

ToSByte(Int32)

Converte il valore dell'intero con segno a 32 bit specificato in un intero con segno a 8 bit equivalente.

ToSByte(Int64)

Converte il valore dell'intero con segno a 64 bit specificato in un intero con segno a 8 bit equivalente.

ToSByte(Byte)

Converte il valore dell'intero senza segno a 8 bit specificato nell'intero con segno a 8 bit equivalente.

ToSByte(Char)

Converte il valore del carattere Unicode specificato nell'intero con segno a 8 bit equivalente.

ToSByte(DateTime)

La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.

ToSByte(Boolean)

Converte il valore booleano specificato nell'intero con segno a 8 bit equivalente.

ToSByte(Double)

Converte il valore del numero a virgola mobile e con precisione doppia specificato in un intero con segno a 8 bit equivalente.

ToSByte(Int16)

Converte il valore dell'intero con segno a 16 bit specificato nell'intero con segno a 8 bit equivalente.

ToSByte(Decimal)

Converte il valore del numero decimale specificato in un intero con segno a 8 bit equivalente.

ToSByte(SByte)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Restituisce l'intero con segno a 8 bit specificato; non viene eseguita alcuna conversione effettiva.

public:
 static System::SByte ToSByte(System::SByte value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (sbyte value);
[<System.CLSCompliant(false)>]
static member ToSByte : sbyte -> sbyte
Public Shared Function ToSByte (value As SByte) As SByte

Parametri

value
SByte

Intero con segno a 8 bit da restituire.

Restituisce

value viene restituito invariato.

Attributi

Si applica a

ToSByte(String, Int32)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte la rappresentazione di stringa di un numero in una base specificata nell'intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::String ^ value, int fromBase);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value, int fromBase);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string? value, int fromBase);
[<System.CLSCompliant(false)>]
static member ToSByte : string * int -> sbyte
Public Shared Function ToSByte (value As String, fromBase As Integer) As SByte

Parametri

value
String

Stringa che contiene il numero da convertire.

fromBase
Int32

Base del numero in value, che deve essere 2, 8, 10 o 16.

Restituisce

Intero con segno a 8 bit equivalente al numero in value oppure 0 (zero) se value è null.

Attributi

Eccezioni

Il valore di fromBase non è 2, 8, 10 o 16.

-oppure-

value, che rappresenta un numero con segno non in base 10, è preceduto da un segno negativo.

value contiene un carattere che corrisponde a una cifra non valida nella base specificata da fromBase. Il messaggio di eccezione indica che non ci sono cifre da convertire se il primo carattere in value non è valido; in caso contrario, il messaggio indica che value contiene caratteri finali non validi.

value, che rappresenta un numero con segno non in base 10, è preceduto da un segno negativo.

-oppure-

value rappresenta un numero minore di SByte.MinValue o maggiore di SByte.MaxValue.

Esempio

Nell'esempio seguente viene tentato di interpretare gli elementi in una matrice di stringhe come rappresentazione binaria, ottale ed esadecimale dei valori numerici per convertirli in byte senza segno.

using System;

public class Example
{
   public static void Main()
   {
      int[] baseValues = { 2, 8, 16};
      string[] values = { "FF", "81", "03", "11", "8F", "01", "1C", "111",
                          "123", "18A" };

      // Convert to each supported base.
      foreach (int baseValue in baseValues)
      {
         Console.WriteLine("Converting strings in base {0}:", baseValue);
         foreach (string value in values)
         {
            Console.Write("   '{0,-5}  -->  ", value + "'");
            try {
               Console.WriteLine(Convert.ToSByte(value, baseValue));
            }
            catch (FormatException) {
               Console.WriteLine("Bad Format");
            }
            catch (OverflowException) {
               Console.WriteLine("Out of Range");
            }
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//       Converting strings in base 2:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  Bad Format
//          '11'    -->  3
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  7
//          '123'   -->  Bad Format
//          '18A'   -->  Bad Format
//
//       Converting strings in base 8:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  3
//          '11'    -->  9
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  73
//          '123'   -->  83
//          '18A'   -->  Bad Format
//
//       Converting strings in base 16:
//          'FF'    -->  -1
//          '81'    -->  -127
//          '03'    -->  3
//          '11'    -->  17
//          '8F'    -->  -113
//          '01'    -->  1
//          '1C'    -->  28
//          '111'   -->  Out of Range
//          '123'   -->  Out of Range
//          '18A'   -->  Out of Range
open System

let baseValues =
    [| 2; 8; 16 |]
let values =
    [| "FF"; "81"; "03"; "11"; "8F"; "01"; "1C"; "111"; "123"; "18A" |]

// Convert to each supported base.
for baseValue in baseValues do
    printfn $"Converting strings in base {baseValue}:"
    for value in values do
        printf $"""   '{value + "'",-5}  -->  """
        try
            printfn $"{Convert.ToSByte(value, baseValue)}"
        with
        | :? FormatException ->
            printfn "Bad Format"
        | :? OverflowException ->
            printfn "Out of Range"
    printfn ""

// The example displays the following output:
//       Converting strings in base 2:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  Bad Format
//          '11'    -->  3
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  7
//          '123'   -->  Bad Format
//          '18A'   -->  Bad Format
//
//       Converting strings in base 8:
//          'FF'    -->  Bad Format
//          '81'    -->  Bad Format
//          '03'    -->  3
//          '11'    -->  9
//          '8F'    -->  Bad Format
//          '01'    -->  1
//          '1C'    -->  Bad Format
//          '111'   -->  73
//          '123'   -->  83
//          '18A'   -->  Bad Format
//
//       Converting strings in base 16:
//          'FF'    -->  -1
//          '81'    -->  -127
//          '03'    -->  3
//          '11'    -->  17
//          '8F'    -->  -113
//          '01'    -->  1
//          '1C'    -->  28
//          '111'   -->  Out of Range
//          '123'   -->  Out of Range
//          '18A'   -->  Out of Range
Module Example
   Public Sub Main()
      Dim bases() As Integer = { 2, 8, 16}
      Dim values() As String = { "FF", "81", "03", "11", "8F", "01", "1C", _ 
                                 "111", "123", "18A" } 
   
      ' Convert to each supported base.
      For Each base As Integer In bases
         Console.WriteLine("Converting strings in base {0}:", base)
         For Each value As String In values
            Console.Write("   '{0,-5}  -->  ", value + "'")
            Try
               Console.WriteLine(Convert.ToSByte(value, base))
            Catch e As FormatException
               Console.WriteLine("Bad Format")
            Catch e As OverflowException
               Console.WriteLine("Out of Range")
            End Try   
         Next
         Console.WriteLine()
      Next
   End Sub
End Module
' The example displays the following output:
'       Converting strings in base 2:
'          'FF'    -->  Bad Format
'          '81'    -->  Bad Format
'          '03'    -->  Bad Format
'          '11'    -->  3
'          '8F'    -->  Bad Format
'          '01'    -->  1
'          '1C'    -->  Bad Format
'          '111'   -->  7
'          '123'   -->  Bad Format
'          '18A'   -->  Bad Format
'       
'       Converting strings in base 8:
'          'FF'    -->  Bad Format
'          '81'    -->  Bad Format
'          '03'    -->  3
'          '11'    -->  9
'          '8F'    -->  Bad Format
'          '01'    -->  1
'          '1C'    -->  Bad Format
'          '111'   -->  73
'          '123'   -->  83
'          '18A'   -->  Bad Format
'       
'       Converting strings in base 16:
'          'FF'    -->  -1
'          '81'    -->  -127
'          '03'    -->  3
'          '11'    -->  17
'          '8F'    -->  -113
'          '01'    -->  1
'          '1C'    -->  28
'          '111'   -->  Out of Range
'          '123'   -->  Out of Range
'          '18A'   -->  Out of Range

Commenti

Se fromBase è 16, è possibile prefisso il numero specificato dal value parametro con "0x" o "0X".

Poiché il segno negativo non è supportato per rappresentazioni numeriche non di base 10, il ToSByte(String, Int32) metodo presuppone che i numeri negativi usino la rappresentazione di complemento di due. In altre parole, il metodo interpreta sempre il bit di ordine elevato di un byte (bit 7) come bit di segno. Di conseguenza, è possibile scrivere codice in cui un numero non di base 10 non compreso nell'intervallo del SByte tipo di dati viene convertito in un SByte valore senza che il metodo generi un'eccezione. Nell'esempio seguente viene eseguita la conversione MaxValue nella rappresentazione stringa esadecimale e quindi viene chiamato il ToSByte(String, Int32) metodo . Anziché generare un'eccezione, il metodo visualizza il messaggio "0xff converte in -1".

// Create a hexadecimal value out of range of the SByte type.
string value = Convert.ToString(byte.MaxValue, 16);
// Convert it back to a number.
try
{
   sbyte number = Convert.ToSByte(value, 16);
   Console.WriteLine("0x{0} converts to {1}.", value, number);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a signed byte.", value);
}
// Create a hexadecimal value out of range of the SByte type.
let value = Convert.ToString(Byte.MaxValue, 16)
// Convert it back to a number.
try
    let number = Convert.ToSByte(value, 16)
    printfn $"0x{value} converts to {number}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to a signed byte."
' Create a hexadecimal value out of range of the SByte type.
Dim value As String = Convert.ToString(Byte.MaxValue, 16)
' Convert it back to a number.
Try
   Dim number As SByte = Convert.ToSByte(value, 16)
   Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a signed byte.", value)
End Try

Quando si eseguono operazioni binarie o conversioni numeriche, è sempre responsabilità dello sviluppatore verificare che un metodo usi la rappresentazione numerica appropriata per interpretare un determinato valore. Come illustrato nell'esempio seguente, è possibile assicurarsi che il metodo gestisca correttamente i overflow determinando prima se un valore rappresenta un tipo non firmato o firmato durante la conversione nella rappresentazione stringa esadecimale. Generare un'eccezione se il valore originale è un tipo non firmato, ma la conversione torna a un byte firmato restituisce un valore il cui bit di segno è attivo.

// Create a hexadecimal value out of range of the SByte type.
byte sourceNumber = byte.MaxValue;
bool isSigned = Math.Sign(Convert.ToDouble(sourceNumber.GetType().GetField("MinValue").GetValue(null))) == -1;
string value = Convert.ToString(sourceNumber, 16);
sbyte targetNumber;
try
{
   targetNumber = Convert.ToSByte(value, 16);
   if (! isSigned && ((targetNumber & 0x80) != 0))
      throw new OverflowException();
   else
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to a signed byte.", value);
}
// Displays the following to the console:
//    Unable to convert '0xff' to a signed byte.
// Create a hexadecimal value out of range of the SByte type.
let sourceNumber = Byte.MaxValue
let isSigned = sign (Convert.ToDouble(sourceNumber.GetType().GetField("MinValue").GetValue null)) = -1
let value = Convert.ToString(sourceNumber, 16)
try
    let targetNumber = Convert.ToSByte(value, 16)
    if not isSigned && targetNumber &&& 0x80y <> 0y then
        raise (OverflowException())
    else
    printfn $"0x{value} converts to {targetNumber}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to a signed byte."
// Displays the following to the console:
//    Unable to convert '0xff' to a signed byte.
' Create a negative hexadecimal value out of range of the Long type.
Dim sourceNumber As Byte = Byte.MaxValue
Dim isSigned As Boolean = Math.Sign(sourceNumber.MinValue) = -1
Dim value As String = Convert.ToString(sourceNumber, 16)
Dim targetNumber As SByte
Try
   targetNumber = Convert.ToSByte(value, 16)
   If Not isSigned And ((targetNumber And &H80) <> 0) Then
      Throw New OverflowException()
   Else 
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber)
   End If    
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to a signed byte.", value)
End Try 
' Displays the following to the console:
'    Unable to convert '0xff' to a signed byte.

Si applica a

ToSByte(String, IFormatProvider)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte la rappresentazione di stringa specificata di un numero in un intero con segno a 8 bit equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.

public:
 static System::SByte ToSByte(System::String ^ value, IFormatProvider ^ provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value, IFormatProvider provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value, IFormatProvider? provider);
[<System.CLSCompliant(false)>]
static member ToSByte : string * IFormatProvider -> sbyte
Public Shared Function ToSByte (value As String, provider As IFormatProvider) As SByte

Parametri

value
String

Stringa che contiene il numero da convertire.

provider
IFormatProvider

Oggetto che fornisce informazioni di formattazione specifiche delle impostazioni cultura.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è null.

value non è costituito da un segno facoltativo seguito da una sequenza di cifre (da 0 a 9).

value rappresenta un numero minore di SByte.MinValue o maggiore di SByte.MaxValue.

Esempio

L'esempio seguente converte le rappresentazioni di stringa dei SByte valori con il ToSByte metodo usando un IFormatProvider oggetto .

// Example of the Convert::ToSByte( String* ) and 
// Convert::ToSByte( String*, IFormatProvider* ) methods.
using namespace System;
using namespace System::Globalization;
const __wchar_t * protoFmt = L"{0,-20}{1,-20}{2}";

// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
   String^ exceptionType = ex->GetType()->ToString();
   return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}

void ConvertToSByte( String^ numericStr, IFormatProvider^ provider )
{
   Object^ defaultValue;
   Object^ providerValue;
   
   // Convert numericStr to SByte without a format provider.
   try
   {
      defaultValue = Convert::ToSByte( numericStr );
   }
   catch ( Exception^ ex ) 
   {
      defaultValue = GetExceptionType( ex );
   }

   
   // Convert numericStr to SByte with a format provider.
   try
   {
      providerValue = Convert::ToSByte( numericStr, provider );
   }
   catch ( Exception^ ex ) 
   {
      providerValue = GetExceptionType( ex );
   }

   Console::WriteLine( gcnew String( protoFmt ), numericStr, defaultValue, providerValue );
}

int main()
{
   
   // Create a NumberFormatInfo object and set several of its
   // properties that apply to numbers.
   NumberFormatInfo^ provider = gcnew NumberFormatInfo;
   
   // These properties affect the conversion.
   provider->NegativeSign = "neg ";
   provider->PositiveSign = "pos ";
   
   // These properties do not affect the conversion.
   // The input string cannot have decimal and group separators.
   provider->NumberDecimalSeparator = ".";
   provider->NumberNegativePattern = 0;
   Console::WriteLine( "This example of\n"
   "  Convert::ToSByte( String* ) and \n"
   "  Convert::ToSByte( String*, IFormatProvider* ) "
   "\ngenerates the following output. It converts "
   "several strings to \nSByte values, using "
   "default formatting or a NumberFormatInfo object.\n" );
   Console::WriteLine( gcnew String( protoFmt ), "String to convert", "Default/exception", "Provider/exception" );
   Console::WriteLine( gcnew String( protoFmt ), "-----------------", "-----------------", "------------------" );
   
   // Convert strings, with and without an IFormatProvider.
   ConvertToSByte( "123", provider );
   ConvertToSByte( "+123", provider );
   ConvertToSByte( "pos 123", provider );
   ConvertToSByte( "-123", provider );
   ConvertToSByte( "neg 123", provider );
   ConvertToSByte( "123.", provider );
   ConvertToSByte( "(123)", provider );
   ConvertToSByte( "128", provider );
   ConvertToSByte( "-129", provider );
}

/*
This example of
  Convert::ToSByte( String* ) and
  Convert::ToSByte( String*, IFormatProvider* )
generates the following output. It converts several strings to
SByte values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToSByteProviderDemo
{
    static string format = "{0,-20}{1,-20}{2}";

     // Get the exception type name; remove the namespace prefix.
    static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring(
            exceptionType.LastIndexOf( '.' ) + 1 );
    }

    static void ConvertToSByte( string numericStr,
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

        // Convert numericStr to SByte without a format provider.
        try
        {
            defaultValue = Convert.ToSByte( numericStr );
        }
        catch( Exception ex )
        {
            defaultValue = GetExceptionType( ex );
        }

        // Convert numericStr to SByte with a format provider.
        try
        {
            providerValue = Convert.ToSByte( numericStr, provider );
        }
        catch( Exception ex )
        {
            providerValue = GetExceptionType( ex );
        }

        Console.WriteLine( format, numericStr,
            defaultValue, providerValue );
    }

    public static void Main( )
    {
        // Create a NumberFormatInfo object and set several of its
        // properties that apply to numbers.
        NumberFormatInfo provider = new NumberFormatInfo();

        // These properties affect the conversion.
        provider.NegativeSign = "neg ";
        provider.PositiveSign = "pos ";

        // These properties do not affect the conversion.
        // The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = ".";
        provider.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToSByte( string ) and \n" +
            "  Convert.ToSByte( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nSByte values, using " +
            "default formatting or a NumberFormatInfo object.\n" );
        Console.WriteLine( format, "String to convert",
            "Default/exception", "Provider/exception" );
        Console.WriteLine( format, "-----------------",
            "-----------------", "------------------" );

        // Convert strings, with and without an IFormatProvider.
        ConvertToSByte( "123", provider );
        ConvertToSByte( "+123", provider );
        ConvertToSByte( "pos 123", provider );
        ConvertToSByte( "-123", provider );
        ConvertToSByte( "neg 123", provider );
        ConvertToSByte( "123.", provider );
        ConvertToSByte( "(123)", provider );
        ConvertToSByte( "128", provider );
        ConvertToSByte( "-129", provider );
    }
}

/*
This example of
  Convert.ToSByte( string ) and
  Convert.ToSByte( string, IFormatProvider )
generates the following output. It converts several strings to
SByte values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( string, IFormatProvider ) methods.
open System
open System.Globalization

let format obj1 obj2 obj3 = printfn $"{obj1,-20}{obj2,-20}{obj3}"

// Get the exception type name; remove the namespace prefix.
let getExceptionType (ex: exn) =
    let exceptionType = ex.GetType() |> string
    exceptionType.Substring(exceptionType.LastIndexOf '.' + 1 )

let convertToSByte (numericStr: string) (provider: IFormatProvider) =
    // Convert numericStr to SByte without a format provider.
    let defaultValue =
        try
            Convert.ToSByte numericStr
            |> string
        with ex -> 
            getExceptionType ex

    // Convert numericStr to SByte with a format provider.
    let providerValue = 
        try
            Convert.ToSByte(numericStr, provider)
            |> string
        with ex ->
            getExceptionType ex

    format numericStr defaultValue providerValue

// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
let provider = NumberFormatInfo()

// These properties affect the conversion.
provider.NegativeSign <- "neg "
provider.PositiveSign <- "pos "

// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator <- "."
provider.NumberNegativePattern <- 0

printfn
    """This example of
  Convert.ToSByte( string ) and 
  Convert.ToSByte( string, IFormatProvider ) 
generates the following output. It converts several strings to 
SByte values, using default formatting or a NumberFormatInfo object.
"""
format "String to convert" "Default/exception" "Provider/exception"
format "-----------------" "-----------------" "------------------"

// Convert strings, with and without an IFormatProvider.
convertToSByte "123" provider
convertToSByte "+123" provider
convertToSByte "pos 123" provider
convertToSByte "-123" provider 
convertToSByte "neg 123" provider 
convertToSByte "123." provider 
convertToSByte "(123)" provider 
convertToSByte "128" provider 
convertToSByte "-129" provider 


// This example of
//   Convert.ToSByte( string ) and
//   Convert.ToSByte( string, IFormatProvider )
// generates the following output. It converts several strings to
// SByte values, using default formatting or a NumberFormatInfo object.

// String to convert   Default/exception   Provider/exception
// -----------------   -----------------   ------------------
// 123                 123                 123
// +123                123                 FormatException
// pos 123             FormatException     123
// -123                -123                FormatException
// neg 123             FormatException     -123
// 123.                FormatException     FormatException
// (123)               FormatException     FormatException
// 128                 OverflowException   OverflowException
// -129                OverflowException   FormatException
' Example of the Convert.ToSByte( String ) and 
' Convert.ToSByte( String, IFormatProvider ) methods.
Imports System.Globalization

Module ToSByteProviderDemo

    Dim format As String = "{0,-20}{1,-20}{2}"

    ' Get the exception type name; remove the namespace prefix.
    Function GetExceptionType( ex As Exception ) As String

        Dim exceptionType   As String = ex.GetType( ).ToString( )
        Return exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

    Sub ConvertToSByte( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

        ' Convert numericStr to SByte without a format provider.
        Try
            defaultValue = Convert.ToSByte( numericStr )
        Catch ex As Exception
            defaultValue = GetExceptionType( ex )
        End Try

        ' Convert numericStr to SByte with a format provider.
        Try
            providerValue = Convert.ToSByte( numericStr, provider )
        Catch ex As Exception
            providerValue = GetExceptionType( ex )
        End Try

        Console.WriteLine( format, numericStr, _
            defaultValue, providerValue )
    End Sub

    Sub Main( )

        ' Create a NumberFormatInfo object and set several of its
        ' properties that apply to numbers.
        Dim provider  As NumberFormatInfo = new NumberFormatInfo( )

        ' These properties affect the conversion.
        provider.NegativeSign = "neg "
        provider.PositiveSign = "pos "

        ' These properties do not affect the conversion.
        ' The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = "."
        provider.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToSByte( String ) and " & vbCrLf & _
            "  Convert.ToSByte( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "SByte " & _
            "values, using default formatting " & _
            "or a NumberFormatInfo object." & vbCrLf )
        Console.WriteLine( format, "String to convert", _
            "Default/exception", "Provider/exception" )
        Console.WriteLine( format, "-----------------", _
            "-----------------", "------------------" )

        ' Convert strings, with and without an IFormatProvider.
        ConvertToSByte( "123", provider )
        ConvertToSByte( "+123", provider )
        ConvertToSByte( "pos 123", provider )
        ConvertToSByte( "-123", provider )
        ConvertToSByte( "neg 123", provider )
        ConvertToSByte( "123.", provider )
        ConvertToSByte( "(123)", provider )
        ConvertToSByte( "128", provider )
        ConvertToSByte( "-129", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToSByte( String ) and
'   Convert.ToSByte( String, IFormatProvider )
' generates the following output. It converts several strings to
' SByte values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 123                 123                 123
' +123                123                 FormatException
' pos 123             FormatException     123
' -123                -123                FormatException
' neg 123             FormatException     -123
' 123.                FormatException     FormatException
' (123)               FormatException     FormatException
' 128                 OverflowException   OverflowException
' -129                OverflowException   FormatException

Commenti

provider è un'istanza IFormatProvider che ottiene un NumberFormatInfo oggetto. L'oggetto NumberFormatInfo fornisce informazioni specifiche delle impostazioni cultura sul formato di value. Se provider è null, viene usato per NumberFormatInfo le impostazioni cultura correnti.

Se si preferisce non gestire un'eccezione se la conversione ha esito negativo, è possibile chiamare invece il SByte.TryParse metodo. Restituisce un Boolean valore che indica se la conversione ha avuto esito positivo o negativo.

Vedi anche

Si applica a

ToSByte(Object, IFormatProvider)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'oggetto specificato in un intero con segno a 8 bit mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.

public:
 static System::SByte ToSByte(System::Object ^ value, IFormatProvider ^ provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object value, IFormatProvider provider);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object? value, IFormatProvider? provider);
[<System.CLSCompliant(false)>]
static member ToSByte : obj * IFormatProvider -> sbyte
Public Shared Function ToSByte (value As Object, provider As IFormatProvider) As SByte

Parametri

value
Object

Oggetto che implementa l'interfaccia IConvertible.

provider
IFormatProvider

Oggetto che fornisce informazioni di formattazione specifiche delle impostazioni cultura.

Restituisce

Intero con segno a 8 bit equivalente a value oppure zero se value è null.

Attributi

Eccezioni

Il formato di value non è appropriato.

value non implementa l'interfaccia IConvertible.

-oppure-

La conversione non è supportata.

value rappresenta un numero minore di SByte.MinValue o maggiore di SByte.MaxValue.

Esempio

Nell'esempio seguente viene definita una classe che archivia byte firmati e senza segno come stringhe esadecimali insieme a un ByteString campo che indica il segno del byte. La classe ByteString implementa l'interfaccia IConvertible. Il IConvertible.ToSByte metodo chiama il Parse(String, IFormatProvider) metodo per eseguire la conversione. Se ha esito negativo, genera un OverflowExceptionoggetto .

using System;
using System.Globalization;

public enum SignBit { Negative=-1, Zero=0, Positive=1 };

public struct ByteString : IConvertible
{
   private SignBit signBit;
   private string byteString;

   public SignBit Sign
   {
      set { signBit = value; }
      get { return signBit; }
   }

   public string Value
   {
      set {
         if (value.Trim().Length > 2)
            throw new ArgumentException("The string representation of a byte cannot have more than two characters.");
         else
            byteString = value;
      }
      get { return byteString; }
   }

   // IConvertible implementations.
   public TypeCode GetTypeCode() {
      return TypeCode.Object;
   }

   public bool ToBoolean(IFormatProvider provider)
   {
      if (signBit == SignBit.Zero)
         return false;
      else
         return true;
   }

   public byte ToByte(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is out of range of the Byte type.", Convert.ToSByte(byteString, 16)));
      else
         return Byte.Parse(byteString, NumberStyles.HexNumber);
   }

   public char ToChar(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative) {
         throw new OverflowException(String.Format("{0} is out of range of the Char type.", Convert.ToSByte(byteString, 16)));
      }
      else {
         byte byteValue = Byte.Parse(this.byteString, NumberStyles.HexNumber);
         return Convert.ToChar(byteValue);
      }
   }

   public DateTime ToDateTime(IFormatProvider provider)
   {
      throw new InvalidCastException("ByteString to DateTime conversion is not supported.");
   }

   public decimal ToDecimal(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
      {
         sbyte byteValue = SByte.Parse(byteString, NumberStyles.HexNumber);
         return Convert.ToDecimal(byteValue);
      }
      else
      {
         byte byteValue = Byte.Parse(byteString, NumberStyles.HexNumber);
         return Convert.ToDecimal(byteValue);
      }
   }

   public double ToDouble(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToDouble(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToDouble(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public short ToInt16(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt16(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToInt16(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public int ToInt32(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt32(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToInt32(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public long ToInt64(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt64(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToInt64(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public sbyte ToSByte(IFormatProvider provider)
   {
      try {
         return SByte.Parse(byteString, NumberStyles.HexNumber);
      }
      catch (OverflowException e) {
         throw new OverflowException(String.Format("{0} is outside the range of the SByte type.",
                                                   Byte.Parse(byteString, NumberStyles.HexNumber)), e);
      }
   }

   public float ToSingle(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToSingle(SByte.Parse(byteString, NumberStyles.HexNumber));
      else
         return Convert.ToSingle(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public string ToString(IFormatProvider provider)
   {
      return "0x" + this.byteString;
   }

   public object ToType(Type conversionType, IFormatProvider provider)
   {
      switch (Type.GetTypeCode(conversionType))
      {
         case TypeCode.Boolean:
            return this.ToBoolean(null);
         case TypeCode.Byte:
            return this.ToByte(null);
         case TypeCode.Char:
            return this.ToChar(null);
         case TypeCode.DateTime:
            return this.ToDateTime(null);
         case TypeCode.Decimal:
            return this.ToDecimal(null);
         case TypeCode.Double:
            return this.ToDouble(null);
         case TypeCode.Int16:
            return this.ToInt16(null);
         case TypeCode.Int32:
            return this.ToInt32(null);
         case TypeCode.Int64:
            return this.ToInt64(null);
         case TypeCode.Object:
            if (typeof(ByteString).Equals(conversionType))
               return this;
            else
               throw new InvalidCastException(String.Format("Conversion to a {0} is not supported.", conversionType.Name));
         case TypeCode.SByte:
            return this.ToSByte(null);
         case TypeCode.Single:
            return this.ToSingle(null);
         case TypeCode.String:
            return this.ToString(null);
         case TypeCode.UInt16:
            return this.ToUInt16(null);
         case TypeCode.UInt32:
            return this.ToUInt32(null);
         case TypeCode.UInt64:
            return this.ToUInt64(null);
         default:
            throw new InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name));
      }
   }

   public UInt16 ToUInt16(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt16 type.",
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)));
      else
         return Convert.ToUInt16(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public UInt32 ToUInt32(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt32 type.",
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)));
      else
         return Convert.ToUInt32(Byte.Parse(byteString, NumberStyles.HexNumber));
   }

   public UInt64 ToUInt64(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt64 type.",
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)));
      else
         return Convert.ToUInt64(Byte.Parse(byteString, NumberStyles.HexNumber));
   }
}
open System
open System.Globalization

type SignBit =
   | Negative = -1
   | Zero = 0
   | Positive = 1

[<Struct>]
type ByteString =
    val mutable private byteString: string

    val mutable Sign : SignBit

    member this.Value
        with get () = this.byteString
        and set (value: string) =
            if value.Trim().Length > 2 then
                invalidArg "value" "The string representation of a byte cannot have more than two characters."
            this.byteString <- value

    // IConvertible implementations.
    interface IConvertible with
        member _.GetTypeCode() = 
            TypeCode.Object

        member this.ToBoolean(provider: IFormatProvider) =
            this.Sign <> SignBit.Zero

        member this.ToByte(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{Convert.ToSByte(this.byteString, 16)} is out of range of the Byte type.")
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)

        member this.ToChar(provider: IFormatProvider) =
        
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{Convert.ToSByte(this.byteString, 16)} is out of range of the Char type.")
            else
                let byteValue = Byte.Parse(this.byteString, NumberStyles.HexNumber)
                Convert.ToChar byteValue

        member _.ToDateTime(provider: IFormatProvider) =    
            raise (InvalidCastException "ByteString to DateTime conversion is not supported.")

        member this.ToDecimal(provider: IFormatProvider) =    
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDecimal
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDecimal

        member this.ToDouble(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDouble
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToDouble

        member this.ToInt16(provider: IFormatProvider) =    
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt16
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt16

        member this.ToInt32(provider: IFormatProvider) =    
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt32
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt32

        member this.ToInt64(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt64
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToInt64

        member this.ToSByte(provider: IFormatProvider) =    
            try
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
            with :? OverflowException as e ->
                raise (OverflowException($"{Byte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the SByte type.", e) )

        member this.ToSingle(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                SByte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToSingle
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToSingle

        member this.ToString(provider: IFormatProvider) =
            "0x" + this.byteString

        member this.ToType(conversionType: Type, provider: IFormatProvider) =
            let this = this :> IConvertible
            match Type.GetTypeCode conversionType with
            | TypeCode.Boolean ->
                this.ToBoolean null
            | TypeCode.Byte ->
                this.ToByte null
            | TypeCode.Char ->
                this.ToChar null
            | TypeCode.DateTime ->
                this.ToDateTime null
            | TypeCode.Decimal ->
                this.ToDecimal null
            | TypeCode.Double ->
                this.ToDouble null
            | TypeCode.Int16 ->
                this.ToInt16 null
            | TypeCode.Int32 ->
                this.ToInt32 null
            | TypeCode.Int64 ->
                this.ToInt64 null
            | TypeCode.Object ->
                if typeof<ByteString>.Equals conversionType then
                    this
                else
                    raise (InvalidCastException $"Conversion to a {conversionType.Name} is not supported.")
            | TypeCode.SByte ->
                this.ToSByte null
            | TypeCode.Single ->
                this.ToSingle null
            | TypeCode.String ->
                this.ToString null
            | TypeCode.UInt16 ->
                this.ToUInt16 null
            | TypeCode.UInt32 ->
                this.ToUInt32 null
            | TypeCode.UInt64 ->
                this.ToUInt64 null
            | _ ->
                raise (InvalidCastException $"Conversion to {conversionType.Name} is not supported.")

        member this.ToUInt16(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{SByte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the UInt16 type." )
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToUInt16

        member this.ToUInt32(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{SByte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the UInt32 type.")
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToUInt32
    
        member this.ToUInt64(provider: IFormatProvider) =
            if this.Sign = SignBit.Negative then
                raise (OverflowException $"{SByte.Parse(this.byteString, NumberStyles.HexNumber)} is outside the range of the UInt32 type.")
            else
                Byte.Parse(this.byteString, NumberStyles.HexNumber)
                |> Convert.ToUInt64
Imports System.Globalization

Public Enum SignBit As Integer
   Positive = 1
   Zero = 0
   Negative = -1
End Enum

Public Structure ByteString : Implements IConvertible
   Private signBit As SignBit
   Private byteString As String
   
   Public Property Sign As SignBit
      Set
         signBit = value
      End Set
      Get
         Return signBit
      End Get
   End Property
   
   Public Property Value As String
      Set
         If value.Trim().Length > 2 Then
            Throw New ArgumentException("The string representation of a byte cannot have more than two characters.")
         Else
            byteString = value
         End If   
      End Set
      Get
         Return byteString
      End Get
   End Property
   
   ' IConvertible implementations.
   Public Function GetTypeCode() As TypeCode _
                   Implements IConvertible.GetTypeCode
      Return TypeCode.Object
   End Function
   
   Public Function ToBoolean(provider As IFormatProvider) As Boolean _
                   Implements IConvertible.ToBoolean
      If signBit = SignBit.Zero Then
         Return False
      Else
         Return True
      End If
   End Function 
   
   Public Function ToByte(provider As IFormatProvider) As Byte _
                   Implements IConvertible.ToByte
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is out of range of the Byte type.", Convert.ToSByte(byteString, 16))) 
      Else
         Return Byte.Parse(byteString, NumberStyles.HexNumber)
      End If       
   End Function
   
   Public Function ToChar(provider As IFormatProvider) As Char _
                   Implements IConvertible.ToChar
      If signBit = signBit.Negative Then 
         Throw New OverflowException(String.Format("{0} is out of range of the Char type.", Convert.ToSByte(byteString, 16)))
      Else
         Dim byteValue As Byte = Byte.Parse(Me.byteString, NumberStyles.HexNumber)
         Return Convert.ToChar(byteValue)
      End If                
   End Function 
   
   Public Function ToDateTime(provider As IFormatProvider) As Date _
                   Implements IConvertible.ToDateTime
      Throw New InvalidCastException("ByteString to DateTime conversion is not supported.")
   End Function
   
   Public Function ToDecimal(provider As IFormatProvider) As Decimal _
                   Implements IConvertible.ToDecimal
      If signBit = signBit.Negative Then
         Dim byteValue As SByte = SByte.Parse(byteString, NumberStyles.HexNumber)
         Return Convert.ToDecimal(byteValue)
      Else
         Dim byteValue As Byte = Byte.Parse(byteString, NumberStyles.HexNumber)
         Return Convert.ToDecimal(byteValue)
      End If
   End Function
   
   Public Function ToDouble(provider As IFormatProvider) As Double _
                   Implements IConvertible.ToDouble
      If signBit = signBit.Negative Then
         Return Convert.ToDouble(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToDouble(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function   
   
   Public Function ToInt16(provider As IFormatProvider) As Int16 _
                   Implements IConvertible.ToInt16
      If signBit = signBit.Negative Then
         Return Convert.ToInt16(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToInt16(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToInt32(provider As IFormatProvider) As Int32 _
                   Implements IConvertible.ToInt32
      If signBit = signBit.Negative Then
         Return Convert.ToInt32(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToInt32(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToInt64(provider As IFormatProvider) As Int64 _
                   Implements IConvertible.ToInt64
      If signBit = signBit.Negative Then
         Return Convert.ToInt64(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToInt64(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToSByte(provider As IFormatProvider) As SByte _
                   Implements IConvertible.ToSByte
      Try
         Return SByte.Parse(byteString, NumberStyles.HexNumber)
      Catch e As OverflowException
         Throw New OverflowException(String.Format("{0} is outside the range of the SByte type.", _
                                                   Byte.Parse(byteString, NumberStyles.HexNumber)))
      End Try   
   End Function

   Public Function ToSingle(provider As IFormatProvider) As Single _
                   Implements IConvertible.ToSingle
      If signBit = signBit.Negative Then
         Return Convert.ToSingle(SByte.Parse(byteString, NumberStyles.HexNumber))
      Else
         Return Convert.ToSingle(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function

   Public Overloads Function ToString(provider As IFormatProvider) As String _
                   Implements IConvertible.ToString
      Return Me.byteString
   End Function
   
   Public Function ToType(conversionType As Type, provider As IFormatProvider) As Object _
                   Implements IConvertible.ToType
      Select Case Type.GetTypeCode(conversionType)
         Case TypeCode.Boolean 
            Return Me.ToBoolean(Nothing)
         Case TypeCode.Byte
            Return Me.ToByte(Nothing)
         Case TypeCode.Char
            Return Me.ToChar(Nothing)
         Case TypeCode.DateTime
            Return Me.ToDateTime(Nothing)
         Case TypeCode.Decimal
            Return Me.ToDecimal(Nothing)
         Case TypeCode.Double
            Return Me.ToDouble(Nothing)
         Case TypeCode.Int16
            Return Me.ToInt16(Nothing)
         Case TypeCode.Int32
            Return Me.ToInt32(Nothing)
         Case TypeCode.Int64
            Return Me.ToInt64(Nothing)
         Case TypeCode.Object
            If GetType(ByteString).Equals(conversionType) Then
               Return Me
            Else
               Throw New InvalidCastException(String.Format("Conversion to a {0} is not supported.", conversionType.Name))
            End If 
         Case TypeCode.SByte
            Return Me.ToSByte(Nothing)
         Case TypeCode.Single
            Return Me.ToSingle(Nothing)
         Case TypeCode.String
            Return Me.ToString(Nothing)
         Case TypeCode.UInt16
            Return Me.ToUInt16(Nothing)
         Case TypeCode.UInt32
            Return Me.ToUInt32(Nothing)
         Case TypeCode.UInt64
            Return Me.ToUInt64(Nothing)   
         Case Else
            Throw New InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name))   
            
      End Select
   End Function
   
   Public Function ToUInt16(provider As IFormatProvider) As UInt16 _
                   Implements IConvertible.ToUInt16
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is outside the range of the UInt16 type.", _
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)))
      Else
         Return Convert.ToUInt16(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function

   Public Function ToUInt32(provider As IFormatProvider) As UInt32 _
                   Implements IConvertible.ToUInt32
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is outside the range of the UInt32 type.", _
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)))
      Else
         Return Convert.ToUInt32(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
   Public Function ToUInt64(provider As IFormatProvider) As UInt64 _
                   Implements IConvertible.ToUInt64
      If signBit = signBit.Negative Then
         Throw New OverflowException(String.Format("{0} is outside the range of the UInt64 type.", _
                                                   SByte.Parse(byteString, NumberStyles.HexNumber)))
      Else
         Return Convert.ToUInt64(Byte.Parse(byteString, NumberStyles.HexNumber))
      End If   
   End Function
   
End Structure

Nell'esempio seguente viene illustrato come l'implementazione IConvertible.ToSByte della ByteString classe viene chiamata dal Convert.ToSByte(Object, IFormatProvider) metodo .

public class Class1
{
   public static void Main()
   {
      sbyte positiveByte = 120;
      sbyte negativeByte = -101;

      ByteString positiveString = new ByteString();
      positiveString.Sign = (SignBit) Math.Sign(positiveByte);
      positiveString.Value = positiveByte.ToString("X2");

      ByteString negativeString = new ByteString();
      negativeString.Sign = (SignBit) Math.Sign(negativeByte);
      negativeString.Value = negativeByte.ToString("X2");

      try {
         Console.WriteLine("'{0}' converts to {1}.", positiveString.Value, Convert.ToSByte(positiveString));
      }
      catch (OverflowException) {
         Console.WriteLine("0x{0} is outside the range of the Byte type.", positiveString.Value);
      }

      try {
         Console.WriteLine("'{0}' converts to {1}.", negativeString.Value, Convert.ToSByte(negativeString));
      }
      catch (OverflowException) {
         Console.WriteLine("0x{0} is outside the range of the Byte type.", negativeString.Value);
      }
   }
}
// The example displays the following output:
//       '78' converts to 120.
//       '9B' converts to -101.
let positiveByte = 120y
let negativeByte = -101y

let mutable positiveString = ByteString()
positiveString.Sign <- sign positiveByte |> enum
positiveString.Value <- positiveByte.ToString "X2"

let mutable negativeString = ByteString()
negativeString.Sign <- sign negativeByte |> enum
negativeString.Value <- negativeByte.ToString "X2"

try
    printfn $"'{positiveString.Value}' converts to {Convert.ToSByte positiveString}."
with :? OverflowException ->
    printfn $"0x{positiveString.Value} is outside the range of the Byte type."

try
    printfn $"'{negativeString.Value}' converts to {Convert.ToSByte negativeString}."
with :? OverflowException ->
    printfn $"0x{negativeString.Value} is outside the range of the Byte type."

// The example displays the following output:
//       '78' converts to 120.
//       '9B' converts to -101.
Module modMain
   Public Sub Main()
      Dim positiveByte As SByte = 120
      Dim negativeByte As SByte = -101
      
      
      Dim positiveString As New ByteString()
      positiveString.Sign = CType(Math.Sign(positiveByte), SignBit)
      positiveString.Value = positiveByte.ToString("X2")
      
      Dim negativeString As New ByteString()
      negativeString.Sign = CType(Math.Sign(negativeByte), SignBit)
      negativeString.Value = negativeByte.ToString("X2")
      
      Try
         Console.WriteLine("'{0}' converts to {1}.", positiveString.Value, Convert.ToSByte(positiveString))
      Catch e As OverflowException
         Console.WriteLine("0x{0} is outside the range of the Byte type.", positiveString.Value)
      End Try

      Try
         Console.WriteLine("'{0}' converts to {1}.", negativeString.Value, Convert.ToSByte(negativeString))
      Catch e As OverflowException
         Console.WriteLine("0x{0} is outside the range of the Byte type.", negativeString.Value)
      End Try   
   End Sub
End Module
' The example dosplays the following output:
'       '78' converts to 120.
'       '9B' converts to -101.

Commenti

provider consente all'utente di specificare informazioni sulla conversione specifiche delle impostazioni cultura sul contenuto di value. Ad esempio, se value è un oggetto String che rappresenta un numero, provider potrebbe fornire informazioni specifiche delle impostazioni cultura sulla notazione usata per rappresentare tale numero.

I tipi di base ignorano provider; tuttavia, il parametro può essere usato se value è un tipo definito dall'utente che implementa l'interfaccia IConvertible .

Si applica a

ToSByte(UInt64)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 64 bit specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::UInt64 value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (ulong value);
[<System.CLSCompliant(false)>]
static member ToSByte : uint64 -> sbyte
Public Shared Function ToSByte (value As ULong) As SByte

Parametri

value
UInt64

Intero senza segno a 64 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

Nell'esempio seguente viene tentato di convertire ogni elemento in una matrice di interi lunghi in un byte firmato.

ulong[] numbers = { UInt64.MinValue, 121, 340, UInt64.MaxValue };
sbyte result;

foreach (ulong number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt64 value 0 to the SByte value 0.
//    Converted the UInt64 value 121 to the SByte value 121.
//    The UInt64 value 340 is outside the range of the SByte type.
//    The UInt64 value 18446744073709551615 is outside the range of the SByte type.
let numbers =
    [| UInt32.MinValue; 121u; 340u; UInt32.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToSByte number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the SByte type."
// The example displays the following output:
//    Converted the UInt32 value 0 to the SByte value 0.
//    Converted the UInt32 value 121 to the SByte value 121.
//    Converted the UInt32 value 340 to the SByte value 340.
//    The UInt32 value 4294967295 is outside the range of the SByte type.
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As SByte
For Each number As ULong In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt64 value 0 to the SByte value 0.
'    Converted the UInt64 value 121 to the SByte value 121.
'    The UInt64 value 340 is outside the range of the SByte type.
'    The UInt64 value 18446744073709551615 is outside the range of the SByte type.

Si applica a

ToSByte(UInt32)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 32 bit specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::UInt32 value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (uint value);
[<System.CLSCompliant(false)>]
static member ToSByte : uint32 -> sbyte
Public Shared Function ToSByte (value As UInteger) As SByte

Parametri

value
UInt32

Intero senza segno a 32 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

Nell'esempio seguente viene eseguito un tentativo di convertire ogni elemento in una matrice integer in un byte con segno.

uint[] numbers = { UInt32.MinValue, 121, 340, UInt32.MaxValue };
sbyte result;

foreach (uint number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt32 value 0 to the SByte value 0.
//    Converted the UInt32 value 121 to the SByte value 121.
//    The UInt32 value 340 is outside the range of the SByte type.
//    The UInt32 value 4294967295 is outside the range of the SByte type.
let numbers =
    [| UInt16.MinValue; 121us; 340us; UInt16.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToSByte number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the SByte type."
// The example displays the following output:
//    Converted the UInt16 value 0 to the SByte value 0.
//    Converted the UInt16 value 121 to the SByte value 121.
//    Converted the UInt16 value 340 to the SByte value 340.
//    Converted the UInt16 value 65535 to the SByte value 65535.
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As SByte
For Each number As UInteger In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt32 value 0 to the SByte value 0.
'    Converted the UInt32 value 121 to the SByte value 121.
'    The UInt32 value 340 is outside the range of the SByte type.
'    The UInt32 value 4294967295 is outside the range of the SByte type.

Si applica a

ToSByte(String)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte la rappresentazione di stringa specificata di un numero in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::String ^ value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (string? value);
[<System.CLSCompliant(false)>]
static member ToSByte : string -> sbyte
Public Shared Function ToSByte (value As String) As SByte

Parametri

value
String

Stringa che contiene il numero da convertire.

Restituisce

Intero con segno a 8 bit equivalente al numero in value oppure 0 (zero) se value è null.

Attributi

Eccezioni

value non è costituito da un segno facoltativo seguito da una sequenza di cifre (da 0 a 9).

value rappresenta un numero minore di SByte.MinValue o maggiore di SByte.MaxValue.

Esempio

Nell'esempio seguente le rappresentazioni di stringa dei SByte valori con il metodo utilizzano la ToSByte formattazione predefinita.

// Example of the Convert::ToSByte( String* ) and 
// Convert::ToSByte( String*, IFormatProvider* ) methods.
using namespace System;
using namespace System::Globalization;
const __wchar_t * protoFmt = L"{0,-20}{1,-20}{2}";

// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
   String^ exceptionType = ex->GetType()->ToString();
   return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}

void ConvertToSByte( String^ numericStr, IFormatProvider^ provider )
{
   Object^ defaultValue;
   Object^ providerValue;
   
   // Convert numericStr to SByte without a format provider.
   try
   {
      defaultValue = Convert::ToSByte( numericStr );
   }
   catch ( Exception^ ex ) 
   {
      defaultValue = GetExceptionType( ex );
   }

   
   // Convert numericStr to SByte with a format provider.
   try
   {
      providerValue = Convert::ToSByte( numericStr, provider );
   }
   catch ( Exception^ ex ) 
   {
      providerValue = GetExceptionType( ex );
   }

   Console::WriteLine( gcnew String( protoFmt ), numericStr, defaultValue, providerValue );
}

int main()
{
   
   // Create a NumberFormatInfo object and set several of its
   // properties that apply to numbers.
   NumberFormatInfo^ provider = gcnew NumberFormatInfo;
   
   // These properties affect the conversion.
   provider->NegativeSign = "neg ";
   provider->PositiveSign = "pos ";
   
   // These properties do not affect the conversion.
   // The input string cannot have decimal and group separators.
   provider->NumberDecimalSeparator = ".";
   provider->NumberNegativePattern = 0;
   Console::WriteLine( "This example of\n"
   "  Convert::ToSByte( String* ) and \n"
   "  Convert::ToSByte( String*, IFormatProvider* ) "
   "\ngenerates the following output. It converts "
   "several strings to \nSByte values, using "
   "default formatting or a NumberFormatInfo object.\n" );
   Console::WriteLine( gcnew String( protoFmt ), "String to convert", "Default/exception", "Provider/exception" );
   Console::WriteLine( gcnew String( protoFmt ), "-----------------", "-----------------", "------------------" );
   
   // Convert strings, with and without an IFormatProvider.
   ConvertToSByte( "123", provider );
   ConvertToSByte( "+123", provider );
   ConvertToSByte( "pos 123", provider );
   ConvertToSByte( "-123", provider );
   ConvertToSByte( "neg 123", provider );
   ConvertToSByte( "123.", provider );
   ConvertToSByte( "(123)", provider );
   ConvertToSByte( "128", provider );
   ConvertToSByte( "-129", provider );
}

/*
This example of
  Convert::ToSByte( String* ) and
  Convert::ToSByte( String*, IFormatProvider* )
generates the following output. It converts several strings to
SByte values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToSByteProviderDemo
{
    static string format = "{0,-20}{1,-20}{2}";

     // Get the exception type name; remove the namespace prefix.
    static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring(
            exceptionType.LastIndexOf( '.' ) + 1 );
    }

    static void ConvertToSByte( string numericStr,
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

        // Convert numericStr to SByte without a format provider.
        try
        {
            defaultValue = Convert.ToSByte( numericStr );
        }
        catch( Exception ex )
        {
            defaultValue = GetExceptionType( ex );
        }

        // Convert numericStr to SByte with a format provider.
        try
        {
            providerValue = Convert.ToSByte( numericStr, provider );
        }
        catch( Exception ex )
        {
            providerValue = GetExceptionType( ex );
        }

        Console.WriteLine( format, numericStr,
            defaultValue, providerValue );
    }

    public static void Main( )
    {
        // Create a NumberFormatInfo object and set several of its
        // properties that apply to numbers.
        NumberFormatInfo provider = new NumberFormatInfo();

        // These properties affect the conversion.
        provider.NegativeSign = "neg ";
        provider.PositiveSign = "pos ";

        // These properties do not affect the conversion.
        // The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = ".";
        provider.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToSByte( string ) and \n" +
            "  Convert.ToSByte( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nSByte values, using " +
            "default formatting or a NumberFormatInfo object.\n" );
        Console.WriteLine( format, "String to convert",
            "Default/exception", "Provider/exception" );
        Console.WriteLine( format, "-----------------",
            "-----------------", "------------------" );

        // Convert strings, with and without an IFormatProvider.
        ConvertToSByte( "123", provider );
        ConvertToSByte( "+123", provider );
        ConvertToSByte( "pos 123", provider );
        ConvertToSByte( "-123", provider );
        ConvertToSByte( "neg 123", provider );
        ConvertToSByte( "123.", provider );
        ConvertToSByte( "(123)", provider );
        ConvertToSByte( "128", provider );
        ConvertToSByte( "-129", provider );
    }
}

/*
This example of
  Convert.ToSByte( string ) and
  Convert.ToSByte( string, IFormatProvider )
generates the following output. It converts several strings to
SByte values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123                 123                 123
+123                123                 FormatException
pos 123             FormatException     123
-123                -123                FormatException
neg 123             FormatException     -123
123.                FormatException     FormatException
(123)               FormatException     FormatException
128                 OverflowException   OverflowException
-129                OverflowException   FormatException
*/
// Example of the Convert.ToSByte( string ) and
// Convert.ToSByte( string, IFormatProvider ) methods.
open System
open System.Globalization

let format obj1 obj2 obj3 = printfn $"{obj1,-20}{obj2,-20}{obj3}"

// Get the exception type name; remove the namespace prefix.
let getExceptionType (ex: exn) =
    let exceptionType = ex.GetType() |> string
    exceptionType.Substring(exceptionType.LastIndexOf '.' + 1 )

let convertToSByte (numericStr: string) (provider: IFormatProvider) =
    // Convert numericStr to SByte without a format provider.
    let defaultValue =
        try
            Convert.ToSByte numericStr
            |> string
        with ex -> 
            getExceptionType ex

    // Convert numericStr to SByte with a format provider.
    let providerValue = 
        try
            Convert.ToSByte(numericStr, provider)
            |> string
        with ex ->
            getExceptionType ex

    format numericStr defaultValue providerValue

// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
let provider = NumberFormatInfo()

// These properties affect the conversion.
provider.NegativeSign <- "neg "
provider.PositiveSign <- "pos "

// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator <- "."
provider.NumberNegativePattern <- 0

printfn
    """This example of
  Convert.ToSByte( string ) and 
  Convert.ToSByte( string, IFormatProvider ) 
generates the following output. It converts several strings to 
SByte values, using default formatting or a NumberFormatInfo object.
"""
format "String to convert" "Default/exception" "Provider/exception"
format "-----------------" "-----------------" "------------------"

// Convert strings, with and without an IFormatProvider.
convertToSByte "123" provider
convertToSByte "+123" provider
convertToSByte "pos 123" provider
convertToSByte "-123" provider 
convertToSByte "neg 123" provider 
convertToSByte "123." provider 
convertToSByte "(123)" provider 
convertToSByte "128" provider 
convertToSByte "-129" provider 


// This example of
//   Convert.ToSByte( string ) and
//   Convert.ToSByte( string, IFormatProvider )
// generates the following output. It converts several strings to
// SByte values, using default formatting or a NumberFormatInfo object.

// String to convert   Default/exception   Provider/exception
// -----------------   -----------------   ------------------
// 123                 123                 123
// +123                123                 FormatException
// pos 123             FormatException     123
// -123                -123                FormatException
// neg 123             FormatException     -123
// 123.                FormatException     FormatException
// (123)               FormatException     FormatException
// 128                 OverflowException   OverflowException
// -129                OverflowException   FormatException
' Example of the Convert.ToSByte( String ) and 
' Convert.ToSByte( String, IFormatProvider ) methods.
Imports System.Globalization

Module ToSByteProviderDemo

    Dim format As String = "{0,-20}{1,-20}{2}"

    ' Get the exception type name; remove the namespace prefix.
    Function GetExceptionType( ex As Exception ) As String

        Dim exceptionType   As String = ex.GetType( ).ToString( )
        Return exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

    Sub ConvertToSByte( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

        ' Convert numericStr to SByte without a format provider.
        Try
            defaultValue = Convert.ToSByte( numericStr )
        Catch ex As Exception
            defaultValue = GetExceptionType( ex )
        End Try

        ' Convert numericStr to SByte with a format provider.
        Try
            providerValue = Convert.ToSByte( numericStr, provider )
        Catch ex As Exception
            providerValue = GetExceptionType( ex )
        End Try

        Console.WriteLine( format, numericStr, _
            defaultValue, providerValue )
    End Sub

    Sub Main( )

        ' Create a NumberFormatInfo object and set several of its
        ' properties that apply to numbers.
        Dim provider  As NumberFormatInfo = new NumberFormatInfo( )

        ' These properties affect the conversion.
        provider.NegativeSign = "neg "
        provider.PositiveSign = "pos "

        ' These properties do not affect the conversion.
        ' The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = "."
        provider.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToSByte( String ) and " & vbCrLf & _
            "  Convert.ToSByte( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "SByte " & _
            "values, using default formatting " & _
            "or a NumberFormatInfo object." & vbCrLf )
        Console.WriteLine( format, "String to convert", _
            "Default/exception", "Provider/exception" )
        Console.WriteLine( format, "-----------------", _
            "-----------------", "------------------" )

        ' Convert strings, with and without an IFormatProvider.
        ConvertToSByte( "123", provider )
        ConvertToSByte( "+123", provider )
        ConvertToSByte( "pos 123", provider )
        ConvertToSByte( "-123", provider )
        ConvertToSByte( "neg 123", provider )
        ConvertToSByte( "123.", provider )
        ConvertToSByte( "(123)", provider )
        ConvertToSByte( "128", provider )
        ConvertToSByte( "-129", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToSByte( String ) and
'   Convert.ToSByte( String, IFormatProvider )
' generates the following output. It converts several strings to
' SByte values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 123                 123                 123
' +123                123                 FormatException
' pos 123             FormatException     123
' -123                -123                FormatException
' neg 123             FormatException     -123
' 123.                FormatException     FormatException
' (123)               FormatException     FormatException
' 128                 OverflowException   OverflowException
' -129                OverflowException   FormatException

Commenti

L'uso del ToSByte(String) metodo equivale al passaggio value al SByte.Parse(String) metodo . value viene interpretato usando le convenzioni di formattazione delle impostazioni cultura correnti.

Se si preferisce non gestire un'eccezione se la conversione non riesce, è invece possibile chiamare il SByte.TryParse metodo . Restituisce un Boolean valore che indica se la conversione ha avuto esito positivo o negativo.

Vedi anche

Si applica a

ToSByte(Single)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore del numero a virgola mobile e con precisione singola specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(float value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (float value);
[<System.CLSCompliant(false)>]
static member ToSByte : single -> sbyte
Public Shared Function ToSByte (value As Single) As SByte

Parametri

value
Single

Numero a virgola mobile a precisione singola da convertire.

Restituisce

value, arrotondato all'intero con segno a 8 bit più vicino. Se value si trova a metà tra due numeri interi, viene restituito il numero intero pari; vale a dire, 4,5 viene convertito in 4, mentre 5,5 viene convertito in 6.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di Single valori in un byte firmato.

object[] values = { true, -12, 163, 935, 'x', "104", "103.0", "-1",
                    "1.00e2", "One", 1.00e2};
sbyte result;

foreach (object value in values)
{
   try {
      result = Convert.ToSByte(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        value.GetType().Name, value);
   }
   catch (FormatException) {
      Console.WriteLine("The {0} value {1} is not in a recognizable format.",
                        value.GetType().Name, value);
   }
   catch (InvalidCastException) {
      Console.WriteLine("No conversion to a Byte exists for the {0} value {1}.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    Converted the Boolean value true to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    The Int32 value 163 is outside the range of the SByte type.
//    The Int32 value 935 is outside the range of the SByte type.
//    Converted the Char value x to the SByte value 120.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the SByte value 100.
let values: obj[] = 
    [| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
       "104"; "103.0"; "-1"
       "1.00e2"; "One"; 1.00e2; 16.3e42 |]

for value in values do
    try
        let result = Convert.ToSByte value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with 
    | :? OverflowException ->
        printfn $"The {value.GetType().Name} value {value} is outside the range of the SByte type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
    | :? InvalidCastException ->
        printfn $"No conversion to an SByte exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
//    Converted the Boolean value True to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    Converted the Int32 value 163 to the SByte value 163.
//    Converted the Int32 value 935 to the SByte value 935.
//    Converted the Char value x to the SByte value 120.
//    No conversion to an SByte exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the SByte value 100.
//    The Double value 1.63E+43 is outside the range of the SByte type.
Dim values() As Object = { True, -12, 163, 935, "x"c, "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2}
Dim result As SByte
For Each value As Object In values
   Try
      result = Convert.ToSByte(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        value.GetType().Name, value)
   Catch e As FormatException
      Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
                        value.GetType().Name, value)
   Catch e As InvalidCastException
      Console.WriteLine("No conversion to a Byte exists for the {0} value {1}.", _
                        value.GetType().Name, value)
                        
   End Try
Next                           
' The example displays the following output:
'    Converted the Boolean value True to the SByte value 1.
'    Converted the Int32 value -12 to the SByte value -12.
'    The Int32 value 163 is outside the range of the SByte type.
'    The Int32 value 935 is outside the range of the SByte type.
'    Converted the Char value x to the SByte value 120.
'    Converted the String value 104 to the SByte value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the SByte value -1.
'    The String value 1.00e2 is not in a recognizable format.
'    The String value One is not in a recognizable format.
'    Converted the Double value 100 to the SByte value 100.

Vedi anche

Si applica a

ToSByte(Object)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'oggetto specificato in un intero con segno a 8 bit.

public:
 static System::SByte ToSByte(System::Object ^ value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (object? value);
[<System.CLSCompliant(false)>]
static member ToSByte : obj -> sbyte
Public Shared Function ToSByte (value As Object) As SByte

Parametri

value
Object

Oggetto che implementa l'interfaccia IConvertible oppure null.

Restituisce

Intero con segno a 8 bit equivalente a value oppure zero se value è null.

Attributi

Eccezioni

Il formato di value non è appropriato.

value non implementa l'interfaccia IConvertible.

-oppure-

La conversione non è supportata.

value rappresenta un numero minore di SByte.MinValue o maggiore di SByte.MaxValue.

Esempio

Nell'esempio seguente viene eseguito un tentativo di convertire ogni elemento in una matrice di oggetti in un byte firmato.

object[] values = { true, -12, 163, 935, 'x', "104", "103.0", "-1",
                    "1.00e2", "One", 1.00e2};
sbyte result;

foreach (object value in values)
{
   try {
      result = Convert.ToSByte(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        value.GetType().Name, value);
   }
   catch (FormatException) {
      Console.WriteLine("The {0} value {1} is not in a recognizable format.",
                        value.GetType().Name, value);
   }
   catch (InvalidCastException) {
      Console.WriteLine("No conversion to a Byte exists for the {0} value {1}.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    Converted the Boolean value true to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    The Int32 value 163 is outside the range of the SByte type.
//    The Int32 value 935 is outside the range of the SByte type.
//    Converted the Char value x to the SByte value 120.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the SByte value 100.
let values: obj[] = 
    [| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
       "104"; "103.0"; "-1"
       "1.00e2"; "One"; 1.00e2; 16.3e42 |]

for value in values do
    try
        let result = Convert.ToSByte value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with 
    | :? OverflowException ->
        printfn $"The {value.GetType().Name} value {value} is outside the range of the SByte type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
    | :? InvalidCastException ->
        printfn $"No conversion to an SByte exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
//    Converted the Boolean value True to the SByte value 1.
//    Converted the Int32 value -12 to the SByte value -12.
//    Converted the Int32 value 163 to the SByte value 163.
//    Converted the Int32 value 935 to the SByte value 935.
//    Converted the Char value x to the SByte value 120.
//    No conversion to an SByte exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the SByte value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the SByte value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the SByte value 100.
//    The Double value 1.63E+43 is outside the range of the SByte type.
Dim values() As Object = { True, -12, 163, 935, "x"c, "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2}
Dim result As SByte
For Each value As Object In values
   Try
      result = Convert.ToSByte(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        value.GetType().Name, value)
   Catch e As FormatException
      Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
                        value.GetType().Name, value)
   Catch e As InvalidCastException
      Console.WriteLine("No conversion to a Byte exists for the {0} value {1}.", _
                        value.GetType().Name, value)
                        
   End Try
Next                           
' The example displays the following output:
'    Converted the Boolean value True to the SByte value 1.
'    Converted the Int32 value -12 to the SByte value -12.
'    The Int32 value 163 is outside the range of the SByte type.
'    The Int32 value 935 is outside the range of the SByte type.
'    Converted the Char value x to the SByte value 120.
'    Converted the String value 104 to the SByte value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the SByte value -1.
'    The String value 1.00e2 is not in a recognizable format.
'    The String value One is not in a recognizable format.
'    Converted the Double value 100 to the SByte value 100.

Commenti

Il valore restituito è il risultato di richiamare il IConvertible.ToSByte metodo del tipo sottostante di value.

Si applica a

ToSByte(UInt16)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 16 bit specificato nell'intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::UInt16 value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (ushort value);
[<System.CLSCompliant(false)>]
static member ToSByte : uint16 -> sbyte
Public Shared Function ToSByte (value As UShort) As SByte

Parametri

value
UInt16

Intero senza segno a 16 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di interi senza segno a 16 bit in un byte con segno.

ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
sbyte result;

foreach (ushort number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt16 value 0 to the SByte value 0.
//    Converted the UInt16 value 121 to the SByte value 121.
//    The UInt16 value 340 is outside the range of the SByte type.
//    The UInt16 value 65535 is outside the range of the SByte type.
let values = 
    [| "One"; "1.34e28"; "-26.87"; "-18"; "-6.00"
       " 0"; "137"; "1601.9"; string Int32.MaxValue |]

for value in values do
    try
        let result = Convert.ToSByte value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with
    | :? OverflowException ->
        printfn $"{value} is outside the range of the SByte type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value '{value}' is not in a recognizable format."
// The example displays the following output:
//    The String value 'One' is not in a recognizable format.
//    The String value '1.34e28' is not in a recognizable format.
//    The String value '-26.87' is not in a recognizable format.
//    Converted the String value '-18' to the SByte value -18.
//    The String value '-6.00' is not in a recognizable format.
//    Converted the String value ' 0' to the SByte value 0.
//    Converted the String value '137' to the SByte value 137.
//    The String value '1601.9' is not in a recognizable format.
//    Converted the String value '2147483647' to the SByte value 2147483647.
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As SByte
For Each number As UShort In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt16 value 0 to the SByte value 0.
'    Converted the UInt16 value 121 to the SByte value 121.
'    The UInt16 value 340 is outside the range of the SByte type.
'    The UInt16 value 65535 is outside the range of the SByte type.

Si applica a

ToSByte(Int32)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero con segno a 32 bit specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(int value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (int value);
[<System.CLSCompliant(false)>]
static member ToSByte : int -> sbyte
Public Shared Function ToSByte (value As Integer) As SByte

Parametri

value
Int32

Intero con segno a 32 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

Nell'esempio seguente viene eseguito un tentativo di convertire ogni elemento in una matrice di interi con segno in un byte con segno.

int[] numbers = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue };
sbyte result;

foreach (int number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int32 value -2147483648 is outside the range of the SByte type.
//    Converted the Int32 value -1 to the SByte value -1.
//    Converted the Int32 value 0 to the SByte value 0.
//    Converted the Int32 value 121 to the SByte value 121.
//    The Int32 value 340 is outside the range of the SByte type.
//    The Int32 value 2147483647 is outside the range of the SByte type.
let numbers =
    [| Int32.MinValue; -1; 0; 121; 340; Int32.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToSByte number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the SByte type."
// The example displays the following output:
//    The Int32 value -2147483647 is outside the range of the SByte type.
//    Converted the Int32 value -1 to the SByte value -1.
//    Converted the Int32 value 0 to the SByte value 0.
//    Converted the Int32 value 121 to the SByte value 121.
//    Converted the Int32 value 340 to the SByte value 340.
//    The Int32 value 2147483647 is outside the range of the SByte type.
Dim numbers() As Integer = { Int32.MinValue, -1, 0, 121, 340, Int32.MaxValue }
Dim result As SByte
For Each number As Integer In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int32 value -2147483648 is outside the range of the SByte type.
'    Converted the Int32 value -1 to the SByte value -1.
'    Converted the Int32 value 0 to the SByte value 0.
'    Converted the Int32 value 121 to the SByte value 121.
'    The Int32 value 340 is outside the range of the SByte type.
'    The Int32 value 2147483647 is outside the range of the SByte type.

Si applica a

ToSByte(Int64)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero con segno a 64 bit specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(long value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (long value);
[<System.CLSCompliant(false)>]
static member ToSByte : int64 -> sbyte
Public Shared Function ToSByte (value As Long) As SByte

Parametri

value
Int64

Intero con segno a 64 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

Nell'esempio seguente viene eseguito un tentativo di convertire ogni elemento in una matrice di numeri interi lunghi in un byte con segno.

long[] numbers = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue };
sbyte result;
foreach (long number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the SByte type.
//    Converted the Int64 value -1 to the SByte value -1.
//    Converted the Int64 value 0 to the SByte value 0.
//    Converted the Int64 value 121 to the SByte value 121.
//    The Int64 value 340 is outside the range of the SByte type.
//    The Int64 value 9223372036854775807 is outside the range of the SByte type.
let numbers =
    [| Int64.MinValue; -1L; 0L; 121L; 340L; Int64.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToSByte number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the SByte type."
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the SByte type.
//    Converted the Int64 value -1 to the SByte value -1.
//    Converted the Int64 value 0 to the SByte value 0.
//    Converted the Int64 value 121 to the SByte value 121.
//    Converted the Int64 value 340 to the SByte value 340.
//    The Int64 value 9223372036854775807 is outside the range of the SByte type.
Dim numbers() As Long = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue }
Dim result As SByte
For Each number As Long In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int64 value -9223372036854775808 is outside the range of the SByte type.
'    Converted the Int64 value -1 to the SByte value -1.
'    Converted the Int64 value 0 to the SByte value 0.
'    Converted the Int64 value 121 to the SByte value 121.
'    The Int64 value 340 is outside the range of the SByte type.
'    The Int64 value 9223372036854775807 is outside the range of the SByte type.

Si applica a

ToSByte(Byte)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero senza segno a 8 bit specificato nell'intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::Byte value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (byte value);
[<System.CLSCompliant(false)>]
static member ToSByte : byte -> sbyte
Public Shared Function ToSByte (value As Byte) As SByte

Parametri

value
Byte

Intero senza segno a 8 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di byte in un byte firmato.

byte[] numbers = { Byte.MinValue, 10, 100, Byte.MaxValue };
sbyte result;

foreach (byte number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the Byte value 0 to the SByte value 0.
//    Converted the Byte value 10 to the SByte value 10.
//    Converted the Byte value 100 to the SByte value 100.
//    The Byte value 255 is outside the range of the SByte type.
let bytes = 
    [| Byte.MinValue; 14uy; 122uy; Byte.MaxValue |]

for byteValue in bytes do
    let result = Convert.ToSByte byteValue
    printfn $"Converted the {byteValue.GetType().Name} value {byteValue} to the {result.GetType().Name} value {result}."
// The example displays the following output:
//       Converted the Byte value 0 to the SByte value 0.
//       Converted the Byte value 14 to the SByte value 14.
//       Converted the Byte value 122 to the SByte value 122.
//       Converted the Byte value 255 to the SByte value 255.
Dim numbers() As Byte = { Byte.MinValue, 10, 100, Byte.MaxValue }
Dim result As SByte
For Each number As Byte In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the Byte value 0 to the SByte value 0.
'    Converted the Byte value 10 to the SByte value 10.
'    Converted the Byte value 100 to the SByte value 100.
'    The Byte value 255 is outside the range of the SByte type.

Si applica a

ToSByte(Char)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore del carattere Unicode specificato nell'intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(char value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (char value);
[<System.CLSCompliant(false)>]
static member ToSByte : char -> sbyte
Public Shared Function ToSByte (value As Char) As SByte

Parametri

value
Char

Carattere Unicode da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di Char valori in un byte firmato.

char[] chars = { 'a', 'z', '\u0007', '\u0200', '\u1023' };
foreach (char ch in chars)
{
   try {
      sbyte result = Convert.ToSByte(ch);
      Console.WriteLine("{0} is converted to {1}.", ch, result);
   }
   catch (OverflowException) {
      Console.WriteLine("Unable to convert u+{0} to a byte.",
                        Convert.ToInt16(ch).ToString("X4"));
   }
}
// The example displays the following output:
//    a is converted to 97.
//    z is converted to 122.
//     is converted to 7.
//    Unable to convert u+00C8 to a byte.
//    Unable to convert u+03FF to a byte.
let chars = 
    [| 'a'; 'z'; '\u0007'; '\u03FF'; '\u7FFF'; '\uFFFE' |]

for ch in chars do
    try
        let result = Convert.ToSByte ch
        printfn $"Converted the {ch.GetType().Name} value '{ch}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"Unable to convert u+{int ch:X4} to an Int32."
// The example displays the following output:
//       Converted the Char value 'a' to the SByte value 97.
//       Converted the Char value 'z' to the SByte value 122.
//       Converted the Char value '' to the SByte value 7.
//       Converted the Char value 'Ͽ' to the SByte value 1023.
//       Converted the Char value '翿' to the SByte value 32767.
//       Converted the Char value '' to the SByte value 65534.
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(200), ChrW(1023) }
For Each ch As Char in chars
   Try
      Dim result As SByte = Convert.ToSByte(ch)
      Console.WriteLine("{0} is converted to {1}.", ch, result)
   Catch e As OverflowException
      Console.WriteLine("Unable to convert u+{0} to a byte.", _
                        AscW(ch).ToString("X4"))
   End Try
Next   
' The example displays the following output:
'    a is converted to 97.
'    z is converted to 122.
'     is converted to 7.
'    Unable to convert u+00C8 to a byte.
'    Unable to convert u+03FF to a byte.

Si applica a

ToSByte(DateTime)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.

public:
 static System::SByte ToSByte(DateTime value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (DateTime value);
[<System.CLSCompliant(false)>]
static member ToSByte : DateTime -> sbyte
Public Shared Function ToSByte (value As DateTime) As SByte

Parametri

value
DateTime

Valore di data e ora da convertire.

Restituisce

Questa conversione non è supportata. Non vengono restituiti valori.

Attributi

Eccezioni

Questa conversione non è supportata.

Si applica a

ToSByte(Boolean)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore booleano specificato nell'intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(bool value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (bool value);
[<System.CLSCompliant(false)>]
static member ToSByte : bool -> sbyte
Public Shared Function ToSByte (value As Boolean) As SByte

Parametri

value
Boolean

Valore booleano da convertire.

Restituisce

Il numero 1 se value è true; in caso contrario, 0.

Attributi

Esempio

Nell'esempio seguente i valori booleani e false i valori true di byte firmati.

bool falseFlag = false;
bool trueFlag = true;

Console.WriteLine("{0} converts to {1}.", falseFlag,
                  Convert.ToSByte(falseFlag));
Console.WriteLine("{0} converts to {1}.", trueFlag,
                  Convert.ToSByte(trueFlag));
// The example displays the following output:
//       false converts to 0.
//       true converts to 1.
let falseFlag = false
let trueFlag = true

printfn $"{falseFlag} converts to {Convert.ToSByte falseFlag}."
printfn $"{trueFlag} converts to {Convert.ToSByte trueFlag}."
// The example displays the following output:
//       False converts to 0.
//       True converts to 1.
Dim falseFlag As Boolean = False
Dim trueFlag As Boolean = True

Console.WriteLine("{0} converts to {1}.", falseFlag, _
                  Convert.ToSByte(falseFlag))
Console.WriteLine("{0} converts to {1}.", trueFlag, _
                  Convert.ToSByte(trueFlag))
' The example displays the following output:
'       False converts to 0.
'       True converts to 1.

Si applica a

ToSByte(Double)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore del numero a virgola mobile e con precisione doppia specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(double value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (double value);
[<System.CLSCompliant(false)>]
static member ToSByte : double -> sbyte
Public Shared Function ToSByte (value As Double) As SByte

Parametri

value
Double

Numero a virgola mobile a precisione doppia da convertire.

Restituisce

value, arrotondato all'intero con segno a 8 bit più vicino. Se value si trova a metà tra due numeri interi, viene restituito il numero intero pari; vale a dire, 4,5 viene convertito in 4, mentre 5,5 viene convertito in 6.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di Double valori in un byte firmato.

double[] numbers = { Double.MinValue, -129.5, -12.7, 0, 16,
                     103.6, 255.0, 1.63509e17, Double.MaxValue};
sbyte result;

foreach (double number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Double value -1.79769313486232E+308 is outside the range of the SByte type.
//    The Double value -129.5 is outside the range of the SByte type.
//    Converted the Double value -12.7 to the SByte value -13.
//    Converted the Double value 0 to the SByte value 0.
//    Converted the Double value 16 to the SByte value 16.
//    Converted the Double value 103.6 to the SByte value 104.
//    The Double value 255 is outside the range of the SByte type.
//    The Double value 1.63509E+17 is outside the range of the SByte type.
//    The Double value 1.79769313486232E+308 is outside the range of the SByte type.
let values = 
    [| Double.MinValue; -1.38e10; -1023.299; -12.98
       0; 9.113e-16; 103.919; 17834.191; Double.MaxValue |]

for value in values do
    try
        let result = Convert.ToSByte value
        printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the SByte type."
//    -1.79769313486232E+308 is outside the range of the SByte type.
//    -13800000000 is outside the range of the SByte type.
//    Converted the Double value '-1023.299' to the SByte value -1023.
//    Converted the Double value '-12.98' to the SByte value -13.
//    Converted the Double value '0' to the SByte value 0.
//    Converted the Double value '9.113E-16' to the SByte value 0.
//    Converted the Double value '103.919' to the SByte value 104.
//    Converted the Double value '17834.191' to the SByte value 17834.
//    1.79769313486232E+308 is outside the range of the SByte type.
Dim numbers() As Double = { Double.MinValue, -129.5, -12.7, 0, 16, _
                            103.6, 255.0, 1.63509e17, Double.MaxValue}
Dim result As SByte

For Each number As Double In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next                                  
' The example displays the following output:
'    The Double value -1.79769313486232E+308 is outside the range of the SByte type.
'    The Double value -129.5 is outside the range of the SByte type.
'    Converted the Double value -12.7 to the SByte value -13.
'    Converted the Double value 0 to the SByte value 0.
'    Converted the Double value 16 to the SByte value 16.
'    Converted the Double value 103.6 to the SByte value 104.
'    The Double value 255 is outside the range of the SByte type.
'    The Double value 1.63509E+17 is outside the range of the SByte type.
'    The Double value 1.79769313486232E+308 is outside the range of the SByte type.

Vedi anche

Si applica a

ToSByte(Int16)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore dell'intero con segno a 16 bit specificato nell'intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(short value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (short value);
[<System.CLSCompliant(false)>]
static member ToSByte : int16 -> sbyte
Public Shared Function ToSByte (value As Short) As SByte

Parametri

value
Int16

Intero con segno a 16 bit da convertire.

Restituisce

Intero con segno a 8 bit equivalente a value.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di interi con segno a 16 bit in un byte con segno.

short[] numbers = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue };
sbyte result;
foreach (short number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int16 value -32768 is outside the range of the SByte type.
//    Converted the Int16 value -1 to the SByte value -1.
//    Converted the Int16 value 0 to the SByte value 0.
//    Converted the Int16 value 121 to the SByte value 121.
//    The Int16 value 340 is outside the range of the SByte type.
//    The Int16 value 32767 is outside the range of the SByte type.
let numbers = 
    [| Int16.MinValue; -1s; 0s; 121s; 340s; Int16.MaxValue |]

for number in numbers do
    let result = Convert.ToSByte number
    printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
// The example displays the following output:
//    Converted the Int16 value -32768 to a Int64 value -32768.
//    Converted the Int16 value -1 to a Int64 value -1.
//    Converted the Int16 value 0 to a Int64 value 0.
//    Converted the Int16 value 121 to a Int64 value 121.
//    Converted the Int16 value 340 to a Int64 value 340.
//    Converted the Int16 value 32767 to a Int64 value 32767.
Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As SByte
For Each number As Short In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int16 value -32768 is outside the range of the SByte type.
'    Converted the Int16 value -1 to the SByte value -1.
'    Converted the Int16 value 0 to the SByte value 0.
'    Converted the Int16 value 121 to the SByte value 121.
'    The Int16 value 340 is outside the range of the SByte type.
'    The Int16 value 32767 is outside the range of the SByte type.

Si applica a

ToSByte(Decimal)

Origine:
Convert.cs
Origine:
Convert.cs
Origine:
Convert.cs

Importante

Questa API non è conforme a CLS.

Converte il valore del numero decimale specificato in un intero con segno a 8 bit equivalente.

public:
 static System::SByte ToSByte(System::Decimal value);
[System.CLSCompliant(false)]
public static sbyte ToSByte (decimal value);
[<System.CLSCompliant(false)>]
static member ToSByte : decimal -> sbyte
Public Shared Function ToSByte (value As Decimal) As SByte

Parametri

value
Decimal

Numero decimale da convertire.

Restituisce

value, arrotondato all'intero con segno a 8 bit più vicino. Se value si trova a metà tra due numeri interi, viene restituito il numero intero pari; vale a dire, 4,5 viene convertito in 4, mentre 5,5 viene convertito in 6.

Attributi

Eccezioni

value è maggiore di SByte.MaxValue o minore di SByte.MinValue.

Esempio

L'esempio seguente tenta di convertire ogni elemento in una matrice di Decimal valori in un byte firmato.

decimal[] numbers = { Decimal.MinValue, -129.5m, -12.7m, 0m, 16m,
                      103.6m, 255.0m, Decimal.MaxValue };
sbyte result;

foreach (decimal number in numbers)
{
   try {
      result = Convert.ToSByte(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Decimal value -79228162514264337593543950335 is outside the range of the SByte type.
//    The Decimal value -129.5 is outside the range of the SByte type.
//    Converted the Decimal value -12.7 to the SByte value -13.
//    Converted the Decimal value 0 to the SByte value 0.
//    Converted the Decimal value 16 to the SByte value 16.
//    Converted the Decimal value 103.6 to the SByte value 104.
//    The Decimal value 255 is outside the range of the SByte type.
//    The Decimal value 79228162514264337593543950335 is outside the range of the SByte type.
let values = 
    [| Decimal.MinValue; -1034.23m; -12m; 0m; 147m
       199.55m; 9214.16m; Decimal.MaxValue |]

for value in values do
    try
        let result = Convert.ToSByte value
        printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the SByte type."
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the SByte type.
//    Converted the Decimal value '-1034.23' to the SByte value -1034.
//    Converted the Decimal value '-12' to the SByte value -12.
//    Converted the Decimal value '0' to the SByte value 0.
//    Converted the Decimal value '147' to the SByte value 147.
//    Converted the Decimal value '199.55' to the SByte value 200.
//    Converted the Decimal value '9214.16' to the SByte value 9214.
//    79228162514264337593543950335 is outside the range of the SByte type.
Dim numbers() As Decimal = { Decimal.MinValue, -129.5d, -12.7d, 0d, 16d, _
                             103.6d, 255.0d, Decimal.MaxValue }
Dim result As SByte

For Each number As Decimal In numbers
   Try
      result = Convert.ToSByte(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the SByte type.", _
                        number.GetType().Name, number)
   End Try
Next                         
' The example displays the following output:
'    The Decimal value -79228162514264337593543950335 is outside the range of the SByte type.
'    The Decimal value -129.5 is outside the range of the SByte type.
'    Converted the Decimal value -12.7 to the SByte value -13.
'    Converted the Decimal value 0 to the SByte value 0.
'    Converted the Decimal value 16 to the SByte value 16.
'    Converted the Decimal value 103.6 to the SByte value 104.
'    The Decimal value 255 is outside the range of the SByte type.
'    The Decimal value 79228162514264337593543950335 is outside the range of the SByte type.

Vedi anche

Si applica a