Decimal-Konstruktor (Double)

Initialisiert eine neue Instanz von Decimal mit dem Wert der angegebenen Gleitkommazahl mit doppelter Genauigkeit.

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

Syntax

'Declaration
Public Sub New ( _
    value As Double _
)
'Usage
Dim value As Double

Dim instance As New Decimal(value)

public Decimal (
    double value
)

public:
Decimal (
    double value
)

public Decimal (
    double value
)

public function Decimal (
    value : double
)

Parameter

• value
  Der als Decimal darzustellende Wert.

Ausnahmen

Hinweise

Dieser Konstruktor rundet value auf 15 signifikante Stellen, wobei auf den nächsten Wert gerundet wird. Dies geschieht auch dann, wenn die Zahl mehr als 15 Stellen hat und die weniger signifikanten Stellen 0 (null) sind.

Beispiel

Im folgenden Codebeispiel werden mehrere Decimal-Zahlen mithilfe der Konstruktorüberladung erstellt, die eine Decimal-Struktur mit einem Double-Wert initialisiert.

' Example of the Decimal( Double ) constructor.
Imports System
Imports Microsoft.VisualBasic

Module DecimalCtorDoDemo

    ' Get the exception type name; remove the namespace prefix.
    Function GetExceptionType( ex As Exception ) As String

        Dim exceptionType   As String = ex.GetType( ).ToString( )
        Return exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

    ' Create a Decimal object and display its value.
    Sub CreateDecimal( value As Double, valToStr As String )

        ' Format and display the constructor.
        Console.Write( "{0,-34}", _
            String.Format( "Decimal( {0} )", valToStr ) )

        ' Construct the Decimal value.
        Try
            Dim decimalNum As New Decimal( value )

            ' Display the value if it was created successfully.
            Console.WriteLine( "{0,31}", decimalNum )

        ' Display the exception type if an exception was thrown.
        Catch ex As Exception
            Console.WriteLine( "{0,31}", GetExceptionType( ex ) )
        End Try
    End Sub
    
    Sub Main( )

        Console.WriteLine( _
            "This example of the Decimal( Double ) constructor " & _
            vbCrLf & "generates the following output." & vbCrLf )
        Console.WriteLine( "{0,-34}{1,31}", "Constructor", _
            "Value or Exception" )
        Console.WriteLine( "{0,-34}{1,31}", "-----------", _
            "------------------" )

        ' Construct Decimal objects from Double values.
        CreateDecimal( 1.23456789E+5, "1.23456789E+5" )                
        CreateDecimal( 1.234567890123E+15, "1.234567890123E+15" )                
        CreateDecimal( 1.2345678901234567E+25, _
            "1.2345678901234567E+25" )
        CreateDecimal( 1.2345678901234567E+35, _
            "1.2345678901234567E+35" )
        CreateDecimal( 1.23456789E-5, "1.23456789E-5" )                
        CreateDecimal( 1.234567890123E-15, "1.234567890123E-15" )      
        CreateDecimal( 1.2345678901234567E-25, _
            "1.2345678901234567E-25" ) 
        CreateDecimal( 1.2345678901234567E-35, _
            "1.2345678901234567E-35" ) 
        CreateDecimal( 1.0 / 7.0, "1.0 / 7.0" ) 
    End Sub 
End Module 

' This example of the Decimal( Double ) constructor
' generates the following output.
' 
' Constructor                                    Value or Exception
' -----------                                    ------------------
' Decimal( 1.23456789E+5 )                               123456.789
' Decimal( 1.234567890123E+15 )                    1234567890123000
' Decimal( 1.2345678901234567E+25 )      12345678901234600000000000
' Decimal( 1.2345678901234567E+35 )               OverflowException
' Decimal( 1.23456789E-5 )                          0.0000123456789
' Decimal( 1.234567890123E-15 )       0.000000000000001234567890123
' Decimal( 1.2345678901234567E-25 )  0.0000000000000000000000001235
' Decimal( 1.2345678901234567E-35 )                               0
' Decimal( 1.0 / 7.0 )                            0.142857142857143

// Example of the decimal( double ) constructor.
using System;

class DecimalCtorDoDemo
{
    // Get the exception type name; remove the namespace prefix.
    public static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring( 
            exceptionType.LastIndexOf( '.' )+1 );
    }

    // Create a decimal object and display its value.
    public static void CreateDecimal( double value, string valToStr )
    {
        // Format and display the constructor.
        Console.Write( "{0,-34}", 
            String.Format( "decimal( {0} )", valToStr ) );

        try
        {
            // Construct the decimal value.
            decimal decimalNum = new decimal( value );

            // Display the value if it was created successfully.
            Console.WriteLine( "{0,31}", decimalNum );
        }
        catch( Exception ex )
        {
            // Display the exception type if an exception was thrown.
            Console.WriteLine( "{0,31}", GetExceptionType( ex ) );
        }
    }
    
    public static void Main( )
    {
        Console.WriteLine( "This example of the decimal( double ) " +
            "constructor \ngenerates the following output.\n" );
        Console.WriteLine( "{0,-34}{1,31}", "Constructor", 
            "Value or Exception" );
        Console.WriteLine( "{0,-34}{1,31}", "-----------", 
            "------------------" );

        // Construct decimal objects from double values.
        CreateDecimal( 1.23456789E+5, "1.23456789E+5" );
        CreateDecimal( 1.234567890123E+15, "1.234567890123E+15" );
        CreateDecimal( 1.2345678901234567E+25, 
            "1.2345678901234567E+25" );
        CreateDecimal( 1.2345678901234567E+35, 
            "1.2345678901234567E+35" );
        CreateDecimal( 1.23456789E-5, "1.23456789E-5" );
        CreateDecimal( 1.234567890123E-15, "1.234567890123E-15" );
        CreateDecimal( 1.2345678901234567E-25, 
            "1.2345678901234567E-25" );
        CreateDecimal( 1.2345678901234567E-35, 
            "1.2345678901234567E-35" );
        CreateDecimal( 1.0 / 7.0, "1.0 / 7.0" );
    }
}

/*
This example of the decimal( double ) constructor
generates the following output.

Constructor                                    Value or Exception
-----------                                    ------------------
decimal( 1.23456789E+5 )                               123456.789
decimal( 1.234567890123E+15 )                    1234567890123000
decimal( 1.2345678901234567E+25 )      12345678901234600000000000
decimal( 1.2345678901234567E+35 )               OverflowException
decimal( 1.23456789E-5 )                          0.0000123456789
decimal( 1.234567890123E-15 )       0.000000000000001234567890123
decimal( 1.2345678901234567E-25 )  0.0000000000000000000000001235
decimal( 1.2345678901234567E-35 )                               0
decimal( 1.0 / 7.0 )                            0.142857142857143
*/

// Example of the Decimal( double ) constructor.
using namespace System;

// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
   String^ exceptionType = ex->GetType()->ToString();
   return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}


// Create a Decimal object and display its value.
void CreateDecimal( double value, String^ valToStr )
{
   
   // Format and display the constructor.
   Console::Write( "{0,-34}", String::Format( "Decimal( {0} )", valToStr ) );
   try
   {
      
      // Construct the Decimal value.
      Decimal decimalNum = Decimal(value);
      
      // Display the value if it was created successfully.
      Console::WriteLine( "{0,31}", decimalNum );
   }
   catch ( Exception^ ex ) 
   {
      
      // Display the exception type if an exception was thrown.
      Console::WriteLine( "{0,31}", GetExceptionType( ex ) );
   }

}

int main()
{
   Console::WriteLine( "This example of the Decimal( double ) "
   "constructor \ngenerates the following output.\n" );
   Console::WriteLine( "{0,-34}{1,31}", "Constructor", "Value or Exception" );
   Console::WriteLine( "{0,-34}{1,31}", "-----------", "------------------" );
   
   // Construct Decimal objects from double values.
   CreateDecimal( 1.23456789E+5, "1.23456789E+5" );
   CreateDecimal( 1.234567890123E+15, "1.234567890123E+15" );
   CreateDecimal( 1.2345678901234567E+25, "1.2345678901234567E+25" );
   CreateDecimal( 1.2345678901234567E+35, "1.2345678901234567E+35" );
   CreateDecimal( 1.23456789E-5, "1.23456789E-5" );
   CreateDecimal( 1.234567890123E-15, "1.234567890123E-15" );
   CreateDecimal( 1.2345678901234567E-25, "1.2345678901234567E-25" );
   CreateDecimal( 1.2345678901234567E-35, "1.2345678901234567E-35" );
   CreateDecimal( 1.0 / 7.0, "1.0 / 7.0" );
}

/*
This example of the Decimal( double ) constructor
generates the following output.

Constructor                                    Value or Exception
-----------                                    ------------------
Decimal( 1.23456789E+5 )                               123456.789
Decimal( 1.234567890123E+15 )                    1234567890123000
Decimal( 1.2345678901234567E+25 )      12345678901234600000000000
Decimal( 1.2345678901234567E+35 )               OverflowException
Decimal( 1.23456789E-5 )                          0.0000123456789
Decimal( 1.234567890123E-15 )       0.000000000000001234567890123
Decimal( 1.2345678901234567E-25 )  0.0000000000000000000000001235
Decimal( 1.2345678901234567E-35 )                               0
Decimal( 1.0 / 7.0 )                            0.142857142857143
*/

// Example of the decimal( double ) constructor.
import System.* ;

class DecimalCtorDoDemo
{   
    // Get the exception type name; remove the namespace prefix.
    public static String GetExceptionType(System.Exception ex)
    {
        String exceptionType = ex.GetType().ToString();
        return exceptionType.Substring((exceptionType.LastIndexOf('.') + 1)) ;
    } //GetExceptionType

    // Create a decimal object and display its value.
    public static void CreateDecimal(double value, String valToStr) 
    {
        // Format and display the constructor.
        Console.Write("{0,-34}", String.Format("decimal( {0} )", valToStr));
        
        try {
            // Construct the decimal value.
            System.Decimal decimalNum =  new System.Decimal(value);
            
            // Display the value if it was created successfully.
            Console.WriteLine("{0,31}", decimalNum);
        }
        catch(System.Exception  ex) {        
            // Display the exception type if an exception was thrown.
            Console.WriteLine("{0,31}", GetExceptionType(ex));
        }
    } //CreateDecimal

    public static void main(String[] args)
    {

        Console.WriteLine(("This example of the decimal( double ) " 
            + "constructor \ngenerates the following output.\n"));
        Console.WriteLine("{0,-34}{1,31}", "Constructor", "Value or Exception");
        Console.WriteLine("{0,-34}{1,31}", "-----------", "------------------");
        
        // Construct decimal objects from double values.
        CreateDecimal(123456.789, "1.23456789E+5");
        CreateDecimal(1.234567890123E+15 , "1.234567890123E+15");
        CreateDecimal(1.23456789012346E+25, "1.2345678901234567E+25");
        CreateDecimal(1.23456789012346E+35, "1.2345678901234567E+35");
        CreateDecimal(1.23456789E-05, "1.23456789E-5");
        CreateDecimal(1.234567890123E-15, "1.234567890123E-15");
        CreateDecimal(1.23456789012346E-25, "1.2345678901234567E-25");
        CreateDecimal(1.23456789012346E-35, "1.2345678901234567E-35");
        CreateDecimal(1.0 / 7.0, "1.0 / 7.0");
    } //main
} //DecimalCtorDoDemo

/*
This example of the decimal( double ) constructor
generates the following output.

Constructor                                    Value or Exception
-----------                                    ------------------
decimal( 1.23456789E+5 )                               123456.789
decimal( 1.234567890123E+15 )                    1234567890123000
decimal( 1.2345678901234567E+25 )      12345678901234600000000000
decimal( 1.2345678901234567E+35 )               OverflowException
decimal( 1.23456789E-5 )                          0.0000123456789
decimal( 1.234567890123E-15 )       0.000000000000001234567890123
decimal( 1.2345678901234567E-25 )  0.0000000000000000000000001235
decimal( 1.2345678901234567E-35 )                               0
decimal( 1.0 / 7.0 )                            0.142857142857143
*/

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

.NET Compact Framework

Unterstützt in: 2.0, 1.0

Siehe auch

Referenz

Decimal-Struktur
Decimal-Member
System-Namespace