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Convert.ToInt32 Method (String, IFormatProvider)

Converts the specified String representation of a number to an equivalent 32-bit signed integer using specified culture-specific formatting information.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

'Declaration
Public Shared Function ToInt32 ( _
	value As String, _
	provider As IFormatProvider _
) As Integer
'Usage
Dim value As String
Dim provider As IFormatProvider
Dim returnValue As Integer

returnValue = Convert.ToInt32(value, provider)
public static int ToInt32 (
	String value, 
	IFormatProvider provider
)
public static function ToInt32 (
	value : String, 
	provider : IFormatProvider
) : int
Not applicable.

Parameters

value

A String containing a number to convert.

provider

An IFormatProvider interface implementation that supplies culture-specific formatting information.

Return Value

A 32-bit signed integer equivalent to the value of value. -or- Zero if value is a null reference (Nothing in Visual Basic).

Exception typeCondition

FormatException

value does not consist of an optional sign followed by a sequence of digits (zero through nine).

OverflowException

value represents a number less than MinValue or greater than MaxValue.

The return value is the result of invoking the Int32.Parse method on value.

provider is an IFormatProvider instance that obtains a NumberFormatInfo object. The NumberFormatInfo object provides culture-specific information about the format of value. If provider is a null reference (Nothing in Visual Basic), the NumberFormatInfo for the current culture is used.

The following code example converts String representations of 32-bit integers with the ToInt32 method, using an IFormatProvider object.

' Example of the Convert.ToInt32( String ) and 
' Convert.ToInt32( String, IFormatProvider ) methods.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic

Module ToInt32ProviderDemo

    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 ConvertToInt32( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

        ' Convert numericStr to Int32 without a format provider.
        Try
            defaultValue = Convert.ToInt32( numericStr )
        Catch ex As Exception
            defaultValue = GetExceptionType( ex )
        End Try

        ' Convert numericStr to Int32 with a format provider.
        Try
            providerValue = Convert.ToInt32( 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.NumberGroupSeparator = ","
        provider.NumberGroupSizes = New Integer( ) { 3 }
        provider.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToInt32( String ) and " & vbCrLf & _
            "  Convert.ToInt32( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "Integer " & _
            "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.
        ConvertToInt32( "123456789", provider )
        ConvertToInt32( "+123456789", provider )
        ConvertToInt32( "pos 123456789", provider )
        ConvertToInt32( "-123456789", provider )
        ConvertToInt32( "neg 123456789", provider )
        ConvertToInt32( "123456789.", provider )
        ConvertToInt32( "123,456,789", provider )
        ConvertToInt32( "(123456789)", provider )
        ConvertToInt32( "2147483648", provider )
        ConvertToInt32( "-2147483649", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToInt32( String ) and
'   Convert.ToInt32( String, IFormatProvider )
' generates the following output. It converts several strings to
' Integer values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 123456789           123456789           123456789
' +123456789          123456789           FormatException
' pos 123456789       FormatException     123456789
' -123456789          -123456789          FormatException
' neg 123456789       FormatException     -123456789
' 123456789.          FormatException     FormatException
' 123,456,789         FormatException     FormatException
' (123456789)         FormatException     FormatException
' 2147483648          OverflowException   OverflowException
' -2147483649         OverflowException   FormatException

// Example of the Convert.ToInt32( string ) and 
// Convert.ToInt32( string, IFormatProvider ) methods.
import System.* ;
import System.Globalization.* ;

class ToInt32ProviderDemo
{
    private static String format = "{0,-20}{1,-20}{2}";   
   
    // Get the exception type name; remove the namespace prefix.
    static String GetExceptionType(System.Exception ex) 
    {
        String exceptionType = ex.GetType().ToString();
        return exceptionType.Substring((exceptionType.LastIndexOf('.') + 1)) ;
    } //GetExceptionType   
   
    static void ConvertToInt32(String numericStr, IFormatProvider provider) 
    {
        Object defaultValue;
        Object providerValue;
      
        // Convert numericStr to Int32 without a format provider.
        try {
            defaultValue = System.Convert.ToString(Convert.ToInt32(numericStr));
        }
        catch(System.Exception  ex) {      
            defaultValue = GetExceptionType(ex);
        }
      
        // Convert numericStr to Int32 with a format provider.
        try {
            providerValue = System.Convert.ToString(
                            Convert.ToInt32(numericStr, provider));
        }
        catch(System.Exception  ex) {      
            providerValue = GetExceptionType(ex);
        }
      
        Console.WriteLine(format, numericStr, defaultValue, providerValue);
     } //ConvertToInt32
      
    public static void main(String[] args)
    {
    
        // Create a NumberFormatInfo object and set several of its
        // properties that apply to numbers.
        NumberFormatInfo provider =  new NumberFormatInfo();
      
        // These properties affect the conversion.
        provider.set_NegativeSign("neg ");
        provider.set_PositiveSign("pos ");
      
        // These properties do not affect the conversion.
        // The input string cannot have decimal and group separators.
        provider.set_NumberDecimalSeparator(".");
        provider.set_NumberGroupSeparator(",");
        provider.set_NumberGroupSizes(new int[]{3});
        provider.set_NumberNegativePattern(0);
      
        Console.WriteLine(("This example of\n" 
            + "  Convert.ToInt32( string ) and \n" 
            + "  Convert.ToInt32( string, IFormatProvider ) " 
            + "\ngenerates the following output. It converts " 
            + "several strings to \nint 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.
        ConvertToInt32("123456789", provider);
        ConvertToInt32("+123456789", provider);
        ConvertToInt32("pos 123456789", provider);
        ConvertToInt32("-123456789", provider);
        ConvertToInt32("neg 123456789", provider);
        ConvertToInt32("123456789.", provider);
        ConvertToInt32("123,456,789", provider);
        ConvertToInt32("(123456789)", provider);
        ConvertToInt32("2147483648", provider);
        ConvertToInt32("-2147483649", provider);
    } //main
} //ToInt32ProviderDemo

/*
This example of
  Convert.ToInt32( string ) and
  Convert.ToInt32( string, IFormatProvider )
generates the following output. It converts several strings to
int values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123456789           123456789           123456789
+123456789          123456789           FormatException
pos 123456789       FormatException     123456789
-123456789          -123456789          FormatException
neg 123456789       FormatException     -123456789
123456789.          FormatException     FormatException
123,456,789         FormatException     FormatException
(123456789)         FormatException     FormatException
2147483648          OverflowException   OverflowException
-2147483649         OverflowException   FormatException
*/

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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