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Convert.ToSingle Method (String, IFormatProvider)

.NET Framework 1.1

Converts the specified String representation of a number to an equivalent single-precision floating point number using the specified culture-specific formatting information.

[Visual Basic]
Overloads Public Shared Function ToSingle( _
   ByVal value As String, _
   ByVal provider As IFormatProvider _
) As Single
[C#]
public static float ToSingle(
 string value,
 IFormatProvider provider
);
[C++]
public: static float ToSingle(
 String* value,
 IFormatProvider* provider
);
[JScript]
public static function ToSingle(
   value : String,
 provider : IFormatProvider
) : float;

Parameters

value
A String containing a number to convert.
provider
An IFormatProvider interface implementation that supplies culture-specific formatting information.

Return Value

A single-precision floating point number equivalent to the value of value.

-or-

Zero if value is a null reference (Nothing in Visual Basic).

Exceptions

Exception Type Condition
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.

Remarks

The return value is the result of invoking the Single.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.

Example

[Visual Basic, C#, C++] The following code example converts String representations of Single values with the ToSingle method, using an IFormatProvider object.

[Visual Basic] 
' Example of the Convert.ToSingle( String ) and 
' Convert.ToSingle( String, IFormatProvider ) methods.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic

Module ToSingleProviderDemo

    Dim formatter As String = "{0,-22}{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( )
        GetExceptionType = exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

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

        Dim defaultValue    As Object
        Dim providerValue   As Object

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

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

        Console.WriteLine( formatter, 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( )

        provider.NumberDecimalSeparator = ","
        provider.NumberGroupSeparator = "."
        provider.NumberGroupSizes = New Integer( ) { 3 }

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToSingle( String ) and " & vbCrLf & _
            "  Convert.ToSingle( String, IFormatProvider ) " & _
            vbCrLf & "generates the " & _
            "following output when run in the [{0}] culture.", _
            CultureInfo.CurrentCulture.Name )
        Console.WriteLine( vbCrLf & _
            "Several strings are converted to Single values, " & _
            "using " & vbCrLf & "default formatting " & _
            "and a NumberFormatInfo object." & vbCrLf )
        Console.WriteLine( formatter, "String to convert", _
            "Default/exception", "Provider/exception" )
        Console.WriteLine( formatter, "-----------------", _
            "-----------------", "------------------" )

        ' Convert strings, with and without an IFormatProvider.
        ConvertToSingle( "1234567", provider )
        ConvertToSingle( "1234.567", provider )
        ConvertToSingle( "1234,567", provider )
        ConvertToSingle( "12,345.67", provider )
        ConvertToSingle( "12.345,67", provider )
        ConvertToSingle( "1,234,567.89", provider )
        ConvertToSingle( "1.234.567,89", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToSingle( String ) and
'   Convert.ToSingle( String, IFormatProvider )
' generates the following output when run in the [en-US] culture.
' 
' Several strings are converted to Single values, using
' default formatting and a NumberFormatInfo object.
' 
' String to convert     Default/exception   Provider/exception
' -----------------     -----------------   ------------------
' 1234567               1234567             1234567
' 1234.567              1234.567            1234567
' 1234,567              1234567             1234.567
' 12,345.67             12345.67            FormatException
' 12.345,67             FormatException     12345.67
' 1,234,567.89          1234568             FormatException
' 1.234.567,89          FormatException     1234568

[C#] 
// Example of the Convert.ToSingle( String ) and 
// Convert.ToSingle( String, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToSingleProviderDemo
{
    static string formatter = "{0,-22}{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 ConvertToSingle( string numericStr, 
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

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

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

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

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

        provider.NumberDecimalSeparator = ",";
        provider.NumberGroupSeparator = ".";
        provider.NumberGroupSizes = new int[ ] { 3 };

        Console.WriteLine( 
            "This example of\n  Convert.ToSingle( String ) and \n" +
            "  Convert.ToSingle( String, IFormatProvider ) \n" +
            "generates the following output when run in the " +
            "[{0}] culture.", 
            CultureInfo.CurrentCulture.Name );
        Console.WriteLine( "\nSeveral " +
            "strings are converted to float values, using \n" +
            "default formatting and a NumberFormatInfo object.\n");
        Console.WriteLine( formatter, "String to convert", 
            "Default/exception", "Provider/exception" );
        Console.WriteLine( formatter, "-----------------", 
            "-----------------", "------------------" );

        // Convert strings, with and without an IFormatProvider.
        ConvertToSingle( "1234567", provider );
        ConvertToSingle( "1234.567", provider );
        ConvertToSingle( "1234,567", provider );
        ConvertToSingle( "12,345.67", provider );
        ConvertToSingle( "12.345,67", provider );
        ConvertToSingle( "1,234,567.89", provider );
        ConvertToSingle( "1.234.567,89", provider );
    }
}

/*
This example of
  Convert.ToSingle( String ) and
  Convert.ToSingle( String, IFormatProvider )
generates the following output when run in the [en-US] culture.

Several strings are converted to float values, using
default formatting and a NumberFormatInfo object.

String to convert     Default/exception   Provider/exception
-----------------     -----------------   ------------------
1234567               1234567             1234567
1234.567              1234.567            1234567
1234,567              1234567             1234.567
12,345.67             12345.67            FormatException
12.345,67             FormatException     12345.67
1,234,567.89          1234568             FormatException
1.234.567,89          FormatException     1234568
*/

[C++] 
// Example of the Convert::ToSingle( String ) and 
// Convert::ToSingle( String, IFormatProvider ) methods.
#using <mscorlib.dll>
using namespace System;
using namespace System::Globalization;

const __wchar_t* formatter = L"{0,-22}{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 ConvertToSingle( String* numericStr, 
    IFormatProvider* provider )
{
    Object* defaultValue;
    Object* providerValue;

    // Convert numericStr to float without a format provider.
    try
    {
        defaultValue = __box( Convert::ToSingle( numericStr ) );
    }
    catch( Exception* ex )
    {
        defaultValue = GetExceptionType( ex );
    }

    // Convert numericStr to float with a format provider.
    try
    {
        providerValue = __box( 
            Convert::ToSingle( numericStr, provider ) );
    }
    catch( Exception* ex )
    {
        providerValue = GetExceptionType( ex );
    }

    Console::WriteLine( new String( formatter ), numericStr, 
        defaultValue, providerValue );
}

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

    provider->NumberDecimalSeparator = S",";
    provider->NumberGroupSeparator = S".";
    Int32 sizes __gc [] = { 3 };
    provider->NumberGroupSizes = sizes;

    Console::WriteLine( 
        S"This example of\n  Convert::ToSingle( String* ) and \n" 
        S"  Convert::ToSingle( String*, IFormatProvider* ) \n" 
        S"generates the following output when run in the " 
        S"[{0}] culture.", 
        CultureInfo::CurrentCulture->Name );
    Console::WriteLine( S"\nSeveral " 
        S"strings are converted to float values, using \n" 
        S"default formatting and a NumberFormatInfo object.\n");
    Console::WriteLine( new String( formatter ), S"String to convert", 
        S"Default/exception", S"Provider/exception" );
    Console::WriteLine( new String( formatter ), S"-----------------", 
        S"-----------------", S"------------------" );

    // Convert strings, with and without an IFormatProvider.
    ConvertToSingle( S"1234567", provider );
    ConvertToSingle( S"1234.567", provider );
    ConvertToSingle( S"1234,567", provider );
    ConvertToSingle( S"12,345.67", provider );
    ConvertToSingle( S"12.345,67", provider );
    ConvertToSingle( S"1,234,567.89", provider );
    ConvertToSingle( S"1.234.567,89", provider );
}

/*
This example of
  Convert::ToSingle( String* ) and
  Convert::ToSingle( String*, IFormatProvider* )
generates the following output when run in the [en-US] culture.

Several strings are converted to float values, using
default formatting and a NumberFormatInfo object.

String to convert     Default/exception   Provider/exception
-----------------     -----------------   ------------------
1234567               1234567             1234567
1234.567              1234.567            1234567
1234,567              1234567             1234.567
12,345.67             12345.67            FormatException
12.345,67             FormatException     12345.67
1,234,567.89          1234568             FormatException
1.234.567,89          FormatException     1234568
*/

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

Convert Class | Convert Members | System Namespace | Convert.ToSingle Overload List

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