指定した値を倍精度浮動小数点数に変換します。
オーバーロードの一覧
指定したブール値を、それと等価な倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Boolean) As Double
[JScript] public static function ToDouble(Boolean) : double;
指定した 8 ビット符号なし整数値を、それと等価な倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Byte) As Double
このメソッドを呼び出すと、必ず InvalidCastException がスローされます。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Char) As Double
このメソッドを呼び出すと、必ず InvalidCastException がスローされます。
[Visual Basic] Overloads Public Shared Function ToDouble(DateTime) As Double
[JScript] public static function ToDouble(DateTime) : double;
指定した Decimal の数値を、それと等価な倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Decimal) As Double
[JScript] public static function ToDouble(Decimal) : double;
指定した倍精度浮動小数点数を返します。実際の変換処理は実行されません。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Double) As Double
指定した 16 ビット符号付き整数の値を等価の倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Short) As Double
指定した 32 ビット符号付き整数の値を等価の倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Integer) As Double
指定した 64 ビット符号付き整数の値を等価の倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Long) As Double
指定した Object の値を、倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Object) As Double
指定した 8 ビット符号付き整数値を、それと等価な倍精度浮動小数点数に変換します。このメソッドは、CLS と互換性がありません。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(SByte) As Double
指定した単精度浮動小数点数値を等価の倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(Single) As Double
指定した String 形式の数値を、それと等価な倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(String) As Double
指定した 16 ビット符号なし整数値を、それと等価な倍精度浮動小数点数に変換します。このメソッドは、CLS と互換性がありません。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(UInt16) As Double
指定した 32 ビット符号なし整数値を、それと等価な倍精度浮動小数点数に変換します。このメソッドは、CLS と互換性がありません。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(UInt32) As Double
指定した 64 ビット符号なし整数値を、それと等価な倍精度浮動小数点数に変換します。このメソッドは、CLS と互換性がありません。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(UInt64) As Double
指定したカルチャに固有の書式情報を使用して、指定した Object の値を倍精度浮動小数点数に変換します。
[Visual Basic] Overloads Public Shared Function ToDouble(Object, IFormatProvider) As Double
[C#] public static double ToDouble(object, IFormatProvider);
[C++] public: static double ToDouble(Object*, IFormatProvider*);
[JScript] public static function ToDouble(Object, IFormatProvider) : double;
指定したカルチャに固有の書式情報を使用して、指定した String 形式の数値を、それと等価な倍精度浮動小数点数に変換します。
.NET Compact Framework でもサポート。
[Visual Basic] Overloads Public Shared Function ToDouble(String, IFormatProvider) As Double
[C#] public static double ToDouble(string, IFormatProvider);
[C++] public: static double ToDouble(String*, IFormatProvider*);
[JScript] public static function ToDouble(String, IFormatProvider) : double;
使用例
[Visual Basic, C#, C++] IFormatProvider オブジェクトを使用し、 String 形式の Double の値を ToDouble メソッドで変換するコード例を次に示します。
[Visual Basic, C#, C++] メモ ここでは、ToDouble のオーバーロード形式のうちの 1 つだけについて、使用例を示します。その他の例については、各オーバーロード形式のトピックを参照してください。
' Example of the Convert.ToDouble( String ) and
' Convert.ToDouble( String, IFormatProvider ) methods.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic
Module ToDoubleProviderDemo
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 ConvertToDouble( numericStr As String, _
provider As IFormatProvider )
Dim defaultValue As Object
Dim providerValue As Object
' Convert numericStr to Double without a format provider.
Try
defaultValue = Convert.ToDouble( numericStr )
Catch ex As Exception
defaultValue = GetExceptionType( ex )
End Try
' Convert numericStr to Double with a format provider.
Try
providerValue = Convert.ToDouble( 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.ToDouble( String ) and " & vbCrLf & _
" Convert.ToDouble( String, IFormatProvider ) " & _
vbCrLf & "generates the " & _
"following output when run in the [{0}] culture.", _
CultureInfo.CurrentCulture.Name )
Console.WriteLine( vbCrLf & _
"Several strings are converted to Double 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.
ConvertToDouble( "123456789", provider )
ConvertToDouble( "12345.6789", provider )
ConvertToDouble( "12345,6789", provider )
ConvertToDouble( "123,456.789", provider )
ConvertToDouble( "123.456,789", provider )
ConvertToDouble( "123,456,789.0123", provider )
ConvertToDouble( "123.456.789,0123", provider )
End Sub
End Module
' This example of
' Convert.ToDouble( String ) and
' Convert.ToDouble( String, IFormatProvider )
' generates the following output when run in the [en-US] culture.
'
' Several strings are converted to Double values, using
' default formatting and a NumberFormatInfo object.
'
' String to convert Default/exception Provider/exception
' ----------------- ----------------- ------------------
' 123456789 123456789 123456789
' 12345.6789 12345.6789 123456789
' 12345,6789 123456789 12345.6789
' 123,456.789 123456.789 FormatException
' 123.456,789 FormatException 123456.789
' 123,456,789.0123 123456789.0123 FormatException
' 123.456.789,0123 FormatException 123456789.0123
[C#]
// Example of the Convert.ToDouble( String ) and
// Convert.ToDouble( String, IFormatProvider ) methods.
using System;
using System.Globalization;
class ToDoubleProviderDemo
{
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 ConvertToDouble( string numericStr,
IFormatProvider provider )
{
object defaultValue;
object providerValue;
// Convert numericStr to double without a format provider.
try
{
defaultValue = Convert.ToDouble( numericStr );
}
catch( Exception ex )
{
defaultValue = GetExceptionType( ex );
}
// Convert numericStr to double with a format provider.
try
{
providerValue = Convert.ToDouble( 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.ToDouble( String ) and \n" +
" Convert.ToDouble( String, IFormatProvider ) \n" +
"generates the following output when run in the " +
"[{0}] culture.",
CultureInfo.CurrentCulture.Name );
Console.WriteLine( "\nSeveral " +
"strings are converted to double 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.
ConvertToDouble( "123456789", provider );
ConvertToDouble( "12345.6789", provider );
ConvertToDouble( "12345,6789", provider );
ConvertToDouble( "123,456.789", provider );
ConvertToDouble( "123.456,789", provider );
ConvertToDouble( "123,456,789.0123", provider );
ConvertToDouble( "123.456.789,0123", provider );
}
}
/*
This example of
Convert.ToDouble( String ) and
Convert.ToDouble( String, IFormatProvider )
generates the following output when run in the [en-US] culture.
Several strings are converted to double values, using
default formatting and a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
123456789 123456789 123456789
12345.6789 12345.6789 123456789
12345,6789 123456789 12345.6789
123,456.789 123456.789 FormatException
123.456,789 FormatException 123456.789
123,456,789.0123 123456789.0123 FormatException
123.456.789,0123 FormatException 123456789.0123
*/
[C++]
// Example of the Convert::ToDouble( String ) and
// Convert::ToDouble( 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 ConvertToDouble( String* numericStr,
IFormatProvider* provider )
{
Object* defaultValue;
Object* providerValue;
// Convert numericStr to Double without a format provider.
try
{
defaultValue = __box( Convert::ToDouble( numericStr ) );
}
catch( Exception* ex )
{
defaultValue = GetExceptionType( ex );
}
// Convert numericStr to Double with a format provider.
try
{
providerValue = __box(
Convert::ToDouble( 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::ToDouble( String* ) and \n"
S" Convert::ToDouble( 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 Double 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.
ConvertToDouble( S"123456789", provider );
ConvertToDouble( S"12345.6789", provider );
ConvertToDouble( S"12345,6789", provider );
ConvertToDouble( S"123,456.789", provider );
ConvertToDouble( S"123.456,789", provider );
ConvertToDouble( S"123,456,789.0123", provider );
ConvertToDouble( S"123.456.789,0123", provider );
}
/*
This example of
Convert::ToDouble( String* ) and
Convert::ToDouble( String*, IFormatProvider* )
generates the following output when run in the [en-US] culture.
Several strings are converted to Double values, using
default formatting and a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
123456789 123456789 123456789
12345.6789 12345.6789 123456789
12345,6789 123456789 12345.6789
123,456.789 123456.789 FormatException
123.456,789 FormatException 123456.789
123,456,789.0123 123456789.0123 FormatException
123.456.789,0123 FormatException 123456789.0123
*/
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