Decimal Narrowing Conversion (Double to Decimal)


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Defines an explicit conversion of a double-precision floating-point number to a Decimal.

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

Public Shared Narrowing Operator CType (
	value As Double
) As Decimal


Type: System.Double

The double-precision floating-point number to convert.

Return Value

Type: System.Decimal

The converted double-precision floating point number.

Exception Condition

value is less than Decimal.MinValue or greater than Decimal.MaxValue.


value is Double.NaN, Double.PositiveInfinity, or Double.NegativeInfinity.

The following example converts Double values to Decimal numbers by using the Double to Decimal conversion. This conversion requires the op_Explicit operator in Visual Basic.

' Example of the explicit conversion from Double to Decimal.
Imports System
Imports Microsoft.VisualBasic

Module DecimalFromDoubleDemo

    Const formatter As String = "{0,25:E16}{1,33}"

    ' 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

    ' Convert the Double argument; catch exceptions that are thrown.
    Sub DecimalFromDouble( argument As Double )

        Dim decValue    As Object

        ' Convert the Double argument to a Decimal value.
            decValue = Decimal.op_Explicit( argument )
        Catch ex As Exception
            decValue = GetExceptionType( ex )
        End Try

        ' Display the Decimal.
        Console.WriteLine( formatter, argument, decValue )
    End Sub 

    Sub Main( )

        Console.WriteLine( _
            "This example of the explicit conversion from Double " & _
            "to Decimal " & vbCrLf & "generates the following " & _
            "output." & vbCrLf )
        Console.WriteLine( formatter, "Double argument", _
            "Decimal value" )
        Console.WriteLine( formatter, "---------------", _
            "-------------" )

        ' Convert Double values and display the results.
        DecimalFromDouble( 1.234567890123E-30 )
        DecimalFromDouble( 1.2345678901234E-25 )
        DecimalFromDouble( 1.23456789012345E-20 )
        DecimalFromDouble( 1.234567890123456E-10 )
        DecimalFromDouble( 1.2345678901234567 )
        DecimalFromDouble( 1.23456789012345678E+12 )
        DecimalFromDouble( 1.234567890123456789E+28 ) 
        DecimalFromDouble( 1.234567890123456789E+30 )
    End Sub 
End Module

' This example of the explicit conversion from Double to Decimal
' generates the following output.
'           Double argument                    Decimal value
'           ---------------                    -------------
'   1.2345678901230000E-030                                0
'   1.2345678901233999E-025   0.0000000000000000000000001235
'   1.2345678901234499E-020   0.0000000000000000000123456789
'   1.2345678901234560E-010       0.000000000123456789012346
'   1.2345678901234567E+000                 1.23456789012346
'   1.2345678901234568E+012                 1234567890123.46
'   1.2345678901234568E+028    12345678901234600000000000000
'   1.2345678901234569E+030                OverflowException

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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