指定した String のインスタンスを返します。実際の変換処理は実行されません。
Overloads Public Shared Function ToString( _
ByVal value As String, _ ByVal provider As IFormatProvider _) As String
[C#]
public static string ToString(stringvalue,IFormatProviderprovider);
[C++]
public: static String* ToString(String* value,IFormatProvider* provider);
[JScript]
public static function ToString(
value : String,provider : IFormatProvider) : String;
パラメータ
- value
String 。 - provider
カルチャに固有の書式情報を提供する IFormatProvider インターフェイス実装。
戻り値
パラメータ value は変更されずに返されます。
解説
このメソッドは provider パラメータを無視します。
使用例
[Visual Basic, C#, C++] ToString メソッドを String 引数で呼び出すと、 String が未変更のまま返され、 IFormatProvider オブジェクトが参照されない場合のコード例を次に示します。
' Example of Convert.ToString( non-numeric types, IFormatProvider ).
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic
' An instance of this class can be passed to methods that require
' an IFormatProvider.
Public Class DummyProvider
Implements IFormatProvider
' Normally, GetFormat returns an object of the requested type
' (usually itself) if it is able; otherwise, it returns Nothing.
Public Function GetFormat( argType As Type ) As Object _
Implements IFormatProvider.GetFormat
' Here, the type of argType is displayed, and GetFormat
' always returns Nothing.
Console.Write( "{0,-40}", argType.ToString( ) )
Return Nothing
End Function
End Class
Module ConvertNonNumericProviderDemo
Sub Main( )
' Create an instance of the IFormatProvider.
Dim provider As New DummyProvider( )
Dim converted As String
' Convert these values using DummyProvider.
Dim Int32A As Integer = -252645135
Dim DoubleA As Double = 61680.3855
Dim ObjDouble As Object = CType( -98765.4321, Object )
Dim DayTimeA As DateTime = _
new DateTime( 2001, 9, 11, 13, 45, 0 )
Dim BoolA As Boolean = True
Dim StringA As String = "Qwerty"
Dim CharA As Char = "$"c
Dim TSpanA As TimeSpan = New TimeSpan( 0, 18, 0 )
Dim ObjOther As Object = CType( provider, Object )
Console.WriteLine( "This example of " & _
"Convert.ToString( non-numeric, IFormatProvider ) " & _
vbCrLf & "generates the following output. The " & _
"provider type, argument type, " & vbCrLf & "and " & _
"argument value are displayed." )
Console.WriteLine( vbCrLf & _
"Note: The IFormatProvider object is not called for " & _
"Boolean, String, " & vbCrLf & "Char, TimeSpan, " & _
"and non-numeric Object." )
' The format provider is called for these conversions.
Console.WriteLine( )
converted = Convert.ToString( Int32A, provider )
Console.WriteLine( "Int32 {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( "Boolean {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 )
End Sub
End Module
' 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 Int32 -252645135
' System.Globalization.NumberFormatInfo Double 61680.3855
' System.Globalization.NumberFormatInfo Object -98765.4321
' System.Globalization.DateTimeFormatInfo DateTime 9/11/2001 1:45:00 PM
'
' Boolean True
' String Qwerty
' Char $
' TimeSpan 00:18:00
' Object DummyProvider
[C#]
// 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
*/
[C++]
// Example of Convert::ToString( non-numeric types, IFormatProvider ).
#using <mscorlib.dll>
using namespace System;
using namespace System::Globalization;
#define null (Object*)0
// An instance of this class can be passed to methods that require
// an IFormatProvider.
__gc class DummyProvider : public 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( S"{0,-40}", argType->ToString( ) );
return null;
}
};
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 = __box( -98765.4321 );
DateTime DayTimeA = DateTime( 2001, 9, 11, 13, 45, 0 );
bool BoolA = true;
String* StringA = S"Qwerty";
Char CharA = '$';
TimeSpan TSpanA = TimeSpan( 0, 18, 0 );
Object* ObjOther = static_cast<Object*>( provider );
Console::WriteLine( S"This example of "
S"Convert::ToString( non-numeric, IFormatProvider* ) \n"
S"generates the following output. The provider type, "
S"argument type, \nand argument value are displayed." );
Console::WriteLine( S"\nNote: The IFormatProvider object is "
S"not called for Boolean, String, \nChar, TimeSpan, "
S"and non-numeric Object." );
// The format provider is called for these conversions.
Console::WriteLine( );
converted = Convert::ToString( Int32A, provider );
Console::WriteLine( S"int {0}", converted );
converted = Convert::ToString( DoubleA, provider );
Console::WriteLine( S"double {0}", converted );
converted = Convert::ToString( ObjDouble, provider );
Console::WriteLine( S"Object {0}", converted );
converted = Convert::ToString( DayTimeA, provider );
Console::WriteLine( S"DateTime {0}", converted );
// The format provider is not called for these conversions.
Console::WriteLine( );
converted = Convert::ToString( BoolA, provider );
Console::WriteLine( S"bool {0}", converted );
converted = Convert::ToString( StringA, provider );
Console::WriteLine( S"String {0}", converted );
converted = Convert::ToString( CharA, provider );
Console::WriteLine( S"Char {0}", converted );
converted = Convert::ToString( __box( TSpanA ), provider );
Console::WriteLine( S"TimeSpan {0}", converted );
converted = Convert::ToString( ObjOther, provider );
Console::WriteLine( S"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
*/
[JScript] JScript のサンプルはありません。Visual Basic、C#、および C++ のサンプルを表示するには、このページの左上隅にある言語のフィルタ ボタン .gif)
をクリックします。
必要条件
プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ
参照
Convert クラス | Convert メンバ | System 名前空間 | Convert.ToString オーバーロードの一覧