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Convert.ToString Method (String, IFormatProvider)

Returns the specified string instance; no actual conversion is performed.

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

public static string ToString(
	string value,
	IFormatProvider provider
)

Parameters

value
Type: System.String

The string to return.

provider
Type: System.IFormatProvider

An object that supplies culture-specific formatting information. This parameter is ignored.

Return Value

Type: System.String
value is returned unchanged.

The following example calls the ToString method with a String parameter. The method returns the unmodified String without referencing the IFormatProvider object.

// Example of Convert.ToString( non-numeric types, IFormatProvider ). 
using System;
using System.Globalization;

// An instance of this class can be passed to methods that require  
// an IFormatProvider. 
public class DummyProvider : IFormatProvider
{
    // Normally, GetFormat returns an object of the requested type 
    // (usually itself) if it is able; otherwise, it returns Nothing.  
    public object GetFormat( Type argType )
    {
        // Here, the type of argType is displayed, and GetFormat 
        // always returns Nothing.
        Console.Write( "{0,-40}", argType.ToString( ) );
        return null;
    }
}

class ConvertNonNumericProviderDemo
{
    static void Main( )
    {
        // Create an instance of the IFormatProvider.
        DummyProvider provider = new DummyProvider( );
        string converted;

        // Convert these values using DummyProvider. 
        int      Int32A     = -252645135;
        double   DoubleA    = 61680.3855;
        object   ObjDouble  = (object)( -98765.4321 );
        DateTime DayTimeA   = new DateTime( 2001, 9, 11, 13, 45, 0 );

        bool     BoolA      = true;
        string   StringA    = "Qwerty";
        char     CharA      = '$';
        TimeSpan TSpanA     = new TimeSpan( 0, 18, 0 );
        object   ObjOther   = (object)provider;

        Console.WriteLine( "This example of " +
            "Convert.ToString( non-numeric, IFormatProvider ) \n" +
            "generates the following output. The provider type, " +
            "argument type, \nand argument value are displayed." );
        Console.WriteLine( "\nNote: The IFormatProvider object is " +
            "not called for Boolean, String, \nChar, TimeSpan, " +
            "and non-numeric Object." );

        // The format provider is called for these conversions.
        Console.WriteLine( );
        converted = Convert.ToString( Int32A, provider );
        Console.WriteLine( "int      {0}", converted );
        converted = Convert.ToString( DoubleA, provider );
        Console.WriteLine( "double   {0}", converted );
        converted = Convert.ToString( ObjDouble, provider );
        Console.WriteLine( "object   {0}", converted );
        converted = Convert.ToString( DayTimeA, provider );
        Console.WriteLine( "DateTime {0}", converted );

        // The format provider is not called for these conversions.
        Console.WriteLine( );
        converted = Convert.ToString( BoolA, provider );
        Console.WriteLine( "bool     {0}", converted );
        converted = Convert.ToString( StringA, provider );
        Console.WriteLine( "string   {0}", converted );
        converted = Convert.ToString( CharA, provider );
        Console.WriteLine( "char     {0}", converted );
        converted = Convert.ToString( TSpanA, provider );
        Console.WriteLine( "TimeSpan {0}", converted );
        converted = Convert.ToString( ObjOther, provider );
        Console.WriteLine( "object   {0}", converted );
    }
}

/*
This example of Convert.ToString( non-numeric, IFormatProvider )
generates the following output. The provider type, argument type,
and argument value are displayed.

Note: The IFormatProvider object is not called for Boolean, String,
Char, TimeSpan, and non-numeric Object.

System.Globalization.NumberFormatInfo   int      -252645135
System.Globalization.NumberFormatInfo   double   61680.3855
System.Globalization.NumberFormatInfo   object   -98765.4321
System.Globalization.DateTimeFormatInfo DateTime 9/11/2001 1:45:00 PM

bool     True
string   Qwerty
char     $
TimeSpan 00:18:00
object   DummyProvider

*/

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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