Decimal.Parse メソッド (String)
String 形式の数値を、それと等価の Decimal に変換します。
Overloads Public Shared Function Parse( _
ByVal s As String _) As Decimal
[C#]
public static decimal Parse(strings);
[C++]
public: static Decimal Parse(String* s);
[JScript]
public static function Parse(
s : String) : Decimal;
パラメータ
- s
変換する数値を格納している String 。
戻り値
s に格納されている数値と等価の Decimal 数値。
例外
| 例外の種類 | 条件 |
|---|---|
| ArgumentNullException | s が null 参照 (Visual Basic では Nothing) です。 |
| FormatException | s の書式が正しくありません。 |
| OverflowException | s が MinValue 未満の数値か、 MaxValue より大きい数値を表しています。 |
解説
パラメータ s が、次の形式の数値を格納しています。
[ws][sign]digits[.fractional-digits][ws]
角かっこ ('[' および ']') で囲まれている項目は省略可能です。その他の項目は次のとおりです。
- ws
省略可能な空白。 - sign
省略可能な符号。 - digits
0 から 9 までの一連の数字。 - '.'
カルチャに固有の小数点記号。 - fractional-digits
0 から 9 までの一連の数字。
パラメータ s は、 NumberStyles.Number スタイルを使用して解釈されます。
パラメータ s は、現在のシステムのカルチャに合わせて初期化されている NumberFormatInfo の書式情報を使用して解析されます。詳細については、「 CurrentInfo 」を参照してください。
必要に応じて、 s の値は近似値に丸められます。
Decimal の精度は 29 桁です。 s が表す数値が 29 桁以上であるが、小数部を含んでおり、 MaxValue と MinValue の範囲内に含まれる場合、その数値は切り捨てられるのではなく、29 桁の近似値に丸められます。
使用例
[Visual Basic, C#, C++] Parse メソッドの複数のオーバーロードを使用して String 形式の Decimal 値を解析するコード例を次に示します。
' Example of the Decimal.Parse( ) methods.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic
Module DecimalParseDemo
Sub DecimalParse( styles As NumberStyles, _
provider As IFormatProvider )
Dim decimalFormats As String( ) = { _
"9876543210.9876543210", "9876543210,9876543210", _
"(9876543210,9876543210)", _
"9,876,543,210,987,654.3210", _
"9.876.543.210.987.654,3210", _
"98_7654_3210_9876,543210" }
' Parse each string in the decimalFormats array, using
' NumberStyles and IFormatProvider, if specified.
Dim decimalString As String
For Each decimalString In decimalFormats
Dim decimalNumber As Decimal
' Display the first part of the output line.
Console.Write( " Parse of {0,-29}", _
String.Format( """{0}""", decimalString ) )
' Use the appropriate Decimal.Parse overload, based on
' the parameters that are specified.
Try
If provider Is Nothing Then
If styles < 0 Then
decimalNumber = _
Decimal.Parse( decimalString )
Else
decimalNumber = _
Decimal.Parse( decimalString, styles )
End If
ElseIf styles < 0 Then
decimalNumber = _
Decimal.Parse( decimalString, provider )
Else
decimalNumber = Decimal.Parse( _
decimalString, styles, provider )
End If
' Display the resulting value if Parse succeeded.
Console.WriteLine( "succeeded: {0}", decimalNumber )
' Display the exception message if Parse failed.
' Truncate the message so it fits on the output line.
Catch ex As Exception
Console.WriteLine( "failed: {0}", _
ex.Message.Substring( 0, 29 ) )
End Try
Next decimalString
End Sub
Sub Main( )
Console.WriteLine( "This example of" & vbCrLf & _
" Decimal.Parse( String )," & vbCrLf & _
" Decimal.Parse( String, NumberStyles )," & vbCrLf & _
" Decimal.Parse( String, IFormatProvider ), and" & _
vbCrLf & " Decimal.Parse( String, NumberStyles, " & _
"IFormatProvider )" & vbCrLf & "generates the " & _
"following output when run in the [{0}] culture.", _
CultureInfo.CurrentCulture.Name )
Console.WriteLine( "Several string representations " & _
"of Decimal values are parsed." )
' IFormatProvider and NumberStyles are not used.
Console.WriteLine( vbCrLf & _
"NumberStyles and IFormatProvider are not " & _
"used; current culture is [{0}]:", _
CultureInfo.CurrentCulture.Name )
DecimalParse( CType( -1, NumberStyles ), Nothing )
' Use the NumberStyle for Currency.
Console.WriteLine( vbCrLf & "NumberStyles.Currency " & _
"is used; IFormatProvider is not used:" )
DecimalParse( NumberStyles.Currency, Nothing )
' Create a CultureInfo object for another culture. Use
' [Dutch - The Netherlands] unless the current culture
' is Dutch language. In that case use [English - U.S.].
Dim cultureName As String = IIf( _
CultureInfo.CurrentCulture.Name.Substring( 0, 2 ) = _
"nl", "en-US", "nl-NL" )
Dim culture As New CultureInfo( cultureName )
Console.WriteLine( vbCrLf & _
"NumberStyles is not used; [{0}] culture " & _
"IFormatProvider is used:", culture.Name )
DecimalParse( CType( -1, NumberStyles ), culture )
' Get the NumberFormatInfo object from CultureInfo, and
' then change the digit group size to 4 and the digit
' separator to '_'.
Dim numInfo As NumberFormatInfo = culture.NumberFormat
numInfo.NumberGroupSizes = New Integer( ) { 4 }
numInfo.NumberGroupSeparator = "_"
' Use the NumberFormatInfo object as the IFormatProvider.
Console.WriteLine( vbCrLf & _
"NumberStyles.Currency is used, group size = 4, " & _
"separator = ""_"":" )
DecimalParse( NumberStyles.Currency, numInfo )
End Sub
End Module
' This example of
' Decimal.Parse( String ),
' Decimal.Parse( String, NumberStyles ),
' Decimal.Parse( String, IFormatProvider ), and
' Decimal.Parse( String, NumberStyles, IFormatProvider )
' generates the following output when run in the [en-US] culture.
' Several string representations of Decimal values are parsed.
'
' NumberStyles and IFormatProvider are not used; current culture is [en-US]:
' Parse of "9876543210.9876543210" succeeded: 9876543210.9876543210
' Parse of "9876543210,9876543210" succeeded: 98765432109876543210
' Parse of "(9876543210,9876543210)" failed: Input string was not in a cor
' Parse of "9,876,543,210,987,654.3210" succeeded: 9876543210987654.3210
' Parse of "9.876.543.210.987.654,3210" failed: Input string was not in a cor
' Parse of "98_7654_3210_9876,543210" failed: Input string was not in a cor
'
' NumberStyles.Currency is used; IFormatProvider is not used:
' Parse of "9876543210.9876543210" succeeded: 9876543210.9876543210
' Parse of "9876543210,9876543210" succeeded: 98765432109876543210
' Parse of "(9876543210,9876543210)" succeeded: -98765432109876543210
' Parse of "9,876,543,210,987,654.3210" succeeded: 9876543210987654.3210
' Parse of "9.876.543.210.987.654,3210" failed: Input string was not in a cor
' Parse of "98_7654_3210_9876,543210" failed: Input string was not in a cor
'
' NumberStyles is not used; [nl-NL] culture IFormatProvider is used:
' Parse of "9876543210.9876543210" succeeded: 98765432109876543210
' Parse of "9876543210,9876543210" succeeded: 9876543210.9876543210
' Parse of "(9876543210,9876543210)" failed: Input string was not in a cor
' Parse of "9,876,543,210,987,654.3210" failed: Input string was not in a cor
' Parse of "9.876.543.210.987.654,3210" succeeded: 9876543210987654.3210
' Parse of "98_7654_3210_9876,543210" failed: Input string was not in a cor
'
' NumberStyles.Currency is used, group size = 4, separator = "_":
' Parse of "9876543210.9876543210" succeeded: 98765432109876543210
' Parse of "9876543210,9876543210" succeeded: 9876543210.9876543210
' Parse of "(9876543210,9876543210)" succeeded: -9876543210.9876543210
' Parse of "9,876,543,210,987,654.3210" failed: Input string was not in a cor
' Parse of "9.876.543.210.987.654,3210" succeeded: 9876543210987654.3210
' Parse of "98_7654_3210_9876,543210" succeeded: 98765432109876.543210
[C#]
// Example of the Decimal.Parse( ) methods.
using System;
using System.Globalization;
class DecimalParseDemo
{
static void DecimalParse( NumberStyles styles,
IFormatProvider provider )
{
string[ ] decimalFormats = { "9876543210.9876543210",
"9876543210,9876543210", "(9876543210,9876543210)",
"9,876,543,210,987,654.3210",
"9.876.543.210.987.654,3210",
"98_7654_3210_9876,543210" };
// Parse each string in the decimalFormats array, using
// NumberStyles and IFormatProvider, if specified.
foreach ( string decimalString in decimalFormats )
{
decimal decimalNumber;
// Display the first part of the output line.
Console.Write(" Parse of {0,-29}",
String.Format( "\"{0}\"", decimalString ) );
try
{
// Use the appropriate Decimal.Parse overload,
// based on the parameters that are specified.
if( provider == null )
if ( styles < 0 )
decimalNumber =
Decimal.Parse( decimalString );
else
decimalNumber = Decimal.Parse(
decimalString, styles );
else
if( styles < 0 )
decimalNumber = Decimal.Parse(
decimalString, provider );
else
decimalNumber = Decimal.Parse(
decimalString, styles, provider );
// Display the resulting value if Parse succeeded.
Console.WriteLine( "succeeded: {0}",
decimalNumber );
}
catch( Exception ex )
{
// Display the exception message if Parse failed.
// Truncate it to fit on the output line.
Console.WriteLine( "failed: {0}",
ex.Message.Substring( 0, 31 ) );
}
}
}
static void Main( )
{
Console.WriteLine( "This example of\n Decimal.Parse( " +
"String ),\n Decimal.Parse( String, NumberStyles " +
"),\n Decimal.Parse( String, IFormatProvider ), " +
"and\n Decimal.Parse( String, NumberStyles, " +
"IFormatProvider )\ngenerates the " +
"following output when run in the [{0}] culture.",
CultureInfo.CurrentCulture.Name );
Console.WriteLine( "Several string representations " +
"of Decimal values are parsed." );
// IFormatProvider and NumberStyles are not used.
Console.WriteLine(
"\nNumberStyles and IFormatProvider are not " +
"used; current culture is [{0}]:",
CultureInfo.CurrentCulture.Name );
DecimalParse( (NumberStyles)(-1), null );
// Use the NumberStyle for Currency.
Console.WriteLine( "\nNumberStyles.Currency " +
"is used; IFormatProvider is not used:" );
DecimalParse( NumberStyles.Currency, null );
// Create a CultureInfo object for another culture. Use
// [Dutch - The Netherlands] unless the current culture
// is Dutch language. In that case use [English - U.S.].
string cultureName =
CultureInfo.CurrentCulture.Name.Substring( 0, 2 ) ==
"nl" ? "en-US" : "nl-NL";
CultureInfo culture = new CultureInfo( cultureName );
Console.WriteLine( "\nNumberStyles is not used; [{0}] " +
"culture IFormatProvider is used:", culture.Name );
DecimalParse( (NumberStyles)(-1), culture );
// Get the NumberFormatInfo object from CultureInfo, and
// then change the digit group size to 4 and the digit
// separator to '_'.
NumberFormatInfo numInfo = culture.NumberFormat;
numInfo.NumberGroupSizes = new int[ ] { 4 };
numInfo.NumberGroupSeparator = "_";
// Use the NumberFormatInfo object as the IFormatProvider.
Console.WriteLine( "\nNumberStyles.Currency is used, " +
"group size = 4, separator = \"_\":" );
DecimalParse( NumberStyles.Currency, numInfo );
}
}
/*
This example of
Decimal.Parse( String ),
Decimal.Parse( String, NumberStyles ),
Decimal.Parse( String, IFormatProvider ), and
Decimal.Parse( String, NumberStyles, IFormatProvider )
generates the following output when run in the [en-US] culture.
Several string representations of Decimal values are parsed.
NumberStyles and IFormatProvider are not used; current culture is [en-US]:
Parse of "9876543210.9876543210" succeeded: 9876543210.9876543210
Parse of "9876543210,9876543210" succeeded: 98765432109876543210
Parse of "(9876543210,9876543210)" failed: Input string was not in a corre
Parse of "9,876,543,210,987,654.3210" succeeded: 9876543210987654.3210
Parse of "9.876.543.210.987.654,3210" failed: Input string was not in a corre
Parse of "98_7654_3210_9876,543210" failed: Input string was not in a corre
NumberStyles.Currency is used; IFormatProvider is not used:
Parse of "9876543210.9876543210" succeeded: 9876543210.9876543210
Parse of "9876543210,9876543210" succeeded: 98765432109876543210
Parse of "(9876543210,9876543210)" succeeded: -98765432109876543210
Parse of "9,876,543,210,987,654.3210" succeeded: 9876543210987654.3210
Parse of "9.876.543.210.987.654,3210" failed: Input string was not in a corre
Parse of "98_7654_3210_9876,543210" failed: Input string was not in a corre
NumberStyles is not used; [nl-NL] culture IFormatProvider is used:
Parse of "9876543210.9876543210" succeeded: 98765432109876543210
Parse of "9876543210,9876543210" succeeded: 9876543210.9876543210
Parse of "(9876543210,9876543210)" failed: Input string was not in a corre
Parse of "9,876,543,210,987,654.3210" failed: Input string was not in a corre
Parse of "9.876.543.210.987.654,3210" succeeded: 9876543210987654.3210
Parse of "98_7654_3210_9876,543210" failed: Input string was not in a corre
NumberStyles.Currency is used, group size = 4, separator = "_":
Parse of "9876543210.9876543210" succeeded: 98765432109876543210
Parse of "9876543210,9876543210" succeeded: 9876543210.9876543210
Parse of "(9876543210,9876543210)" succeeded: -9876543210.9876543210
Parse of "9,876,543,210,987,654.3210" failed: Input string was not in a corre
Parse of "9.876.543.210.987.654,3210" succeeded: 9876543210987654.3210
Parse of "98_7654_3210_9876,543210" succeeded: 98765432109876.543210
*/
[C++]
// Example of the Decimal::Parse( ) methods.
#using <mscorlib.dll>
using namespace System;
using namespace System::Globalization;
using namespace System::Collections;
#define null (IFormatProvider*)0
// Parse each string in the decimalFormats array, using
// NumberStyles and IFormatProvider, if specified.
void DecimalParse( NumberStyles styles, IFormatProvider* provider )
{
String* decimalFormats[ ] = __gc new String*[ 6 ];
decimalFormats[ 0 ] = S"9876543210.9876543210";
decimalFormats[ 1 ] = S"9876543210,9876543210";
decimalFormats[ 2 ] = S"(9876543210,9876543210)";
decimalFormats[ 3 ] = S"9,876,543,210,987,654.3210";
decimalFormats[ 4 ] = S"9.876.543.210.987.654,3210";
decimalFormats[ 5 ] = S"98_7654_3210_9876,543210";
// Code foreach( String* decimalString in decimalFormats ).
IEnumerator* myEnum = decimalFormats->GetEnumerator( );
while( myEnum->MoveNext( ) )
{
String* decimalString =
__try_cast<String*>( myEnum->Current );
Decimal decimalNumber;
// Display the first part of the output line.
Console::Write( S" Parse of {0,-29}",
String::Format( S"\"{0}\"", decimalString ) );
try
{
// Use the appropriate Decimal::Parse overload, based
// on the parameters that are specified.
if( provider == null )
if ( styles < 0 )
decimalNumber =
Decimal::Parse( decimalString );
else
decimalNumber = Decimal::Parse(
decimalString, styles );
else
if( styles < 0 )
decimalNumber = Decimal::Parse(
decimalString, provider );
else
decimalNumber = Decimal::Parse(
decimalString, styles, provider );
// Display the resulting value if Parse succeeded.
Console::WriteLine( S"succeeded: {0}",
__box( decimalNumber ) );
}
catch( Exception* ex )
{
// Display the exception message if Parse failed.
// Truncate it to fit on the output line.
Console::WriteLine( S"failed: {0}",
ex->Message->Substring( 0, 31 ) );
}
}
}
void main( )
{
Console::WriteLine( S"This example of\n"
S" Decimal::Parse( String* ),\n"
S" Decimal::Parse( String*, NumberStyles ),\n"
S" Decimal::Parse( String*, IFormatProvider* ), and\n"
S" Decimal::Parse( String*, NumberStyles, "
S"IFormatProvider* )\ngenerates the "
S"following output when run in the [{0}] culture.",
CultureInfo::CurrentCulture->Name );
Console::WriteLine( S"Several string representations "
S"of Decimal values are parsed." );
// IFormatProvider and NumberStyles are not used.
Console::WriteLine(
S"\nNumberStyles and IFormatProvider are not "
S"used; current culture is [{0}]:",
CultureInfo::CurrentCulture->Name );
DecimalParse( (NumberStyles)(-1), null );
// Use the NumberStyle for Currency.
Console::WriteLine( S"\nNumberStyles::Currency "
S"is used; IFormatProvider is not used:" );
DecimalParse( NumberStyles::Currency, null );
// Create a CultureInfo object for another culture. Use
// [Dutch - The Netherlands] unless the current culture
// is Dutch language. In that case use [English - U.S.].
String* cultureName =
CultureInfo::CurrentCulture->Name->Substring( 0, 2 ) ==
S"nl" ? S"en-US" : S"nl-NL";
CultureInfo* culture = new CultureInfo( cultureName );
Console::WriteLine( S"\nNumberStyles is not used; [{0}] "
S"culture IFormatProvider is used:", culture->Name );
DecimalParse( (NumberStyles)(-1), culture );
// Get the NumberFormatInfo object from CultureInfo, and
// then change the digit group size to 4 and the digit
// separator to '_'.
NumberFormatInfo* numInfo = culture->NumberFormat;
Int32 sizes __gc [] = { 4 };
numInfo->NumberGroupSizes = sizes;
numInfo->NumberGroupSeparator = S"_";
// Use the NumberFormatInfo object as the IFormatProvider.
Console::WriteLine( S"\nNumberStyles::Currency is used, "
S"group size = 4, separator = \"_\":" );
DecimalParse( NumberStyles::Currency, numInfo );
}
/*
This example of
Decimal::Parse( String* ),
Decimal::Parse( String*, NumberStyles ),
Decimal::Parse( String*, IFormatProvider* ), and
Decimal::Parse( String*, NumberStyles, IFormatProvider* )
generates the following output when run in the [en-US] culture.
Several string representations of Decimal values are parsed.
NumberStyles and IFormatProvider are not used; current culture is [en-US]:
Parse of "9876543210.9876543210" succeeded: 9876543210.9876543210
Parse of "9876543210,9876543210" succeeded: 98765432109876543210
Parse of "(9876543210,9876543210)" failed: Input string was not in a corre
Parse of "9,876,543,210,987,654.3210" succeeded: 9876543210987654.3210
Parse of "9.876.543.210.987.654,3210" failed: Input string was not in a corre
Parse of "98_7654_3210_9876,543210" failed: Input string was not in a corre
NumberStyles::Currency is used; IFormatProvider is not used:
Parse of "9876543210.9876543210" succeeded: 9876543210.9876543210
Parse of "9876543210,9876543210" succeeded: 98765432109876543210
Parse of "(9876543210,9876543210)" succeeded: -98765432109876543210
Parse of "9,876,543,210,987,654.3210" succeeded: 9876543210987654.3210
Parse of "9.876.543.210.987.654,3210" failed: Input string was not in a corre
Parse of "98_7654_3210_9876,543210" failed: Input string was not in a corre
NumberStyles is not used; [nl-NL] culture IFormatProvider is used:
Parse of "9876543210.9876543210" succeeded: 98765432109876543210
Parse of "9876543210,9876543210" succeeded: 9876543210.9876543210
Parse of "(9876543210,9876543210)" failed: Input string was not in a corre
Parse of "9,876,543,210,987,654.3210" failed: Input string was not in a corre
Parse of "9.876.543.210.987.654,3210" succeeded: 9876543210987654.3210
Parse of "98_7654_3210_9876,543210" failed: Input string was not in a corre
NumberStyles::Currency is used, group size = 4, separator = "_":
Parse of "9876543210.9876543210" succeeded: 98765432109876543210
Parse of "9876543210,9876543210" succeeded: 9876543210.9876543210
Parse of "(9876543210,9876543210)" succeeded: -9876543210.9876543210
Parse of "9,876,543,210,987,654.3210" failed: Input string was not in a corre
Parse of "9.876.543.210.987.654,3210" succeeded: 9876543210987654.3210
Parse of "98_7654_3210_9876,543210" succeeded: 98765432109876.543210
*/
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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, .NET Compact Framework - Windows CE .NET, Common Language Infrastructure (CLI) Standard
参照
Decimal 構造体 | Decimal メンバ | System 名前空間 | Decimal.Parse オーバーロードの一覧 | 書式設定の概要 | ToString | Math.Round