Articolo
11/18/2011

Convert.ToDecimal Method (Double)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Converts the value of the specified double-precision floating point number to an equivalent Decimal number.

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

Syntax

'Declaration
Public Shared Function ToDecimal ( _
    value As Double _
) As Decimal

public static decimal ToDecimal(
    double value
)

Parameters

value
Type: System.Double
A double-precision floating point number.

Return Value

Type: System.Decimal
A Decimal number equivalent to the value of value.

Exceptions

Exception	Condition
OverflowException	The numeric value of value is greater than MaxValue or less than MinValue.

Remarks

The Decimal value returned by this method contains a maximum of 15 significant digits. If the value parameter contains more than 15 significant digits, it is rounded using rounding to nearest. The following example illustrates how the Convert.ToDecimal(Double) method uses rounding to nearest to return a Decimal value with 15 significant digits.

outputBlock.Text &= Convert.ToDecimal(1.234567890123455E+17R) & vbCrLf   ' Displays 1234568000
outputBlock.Text &= Convert.ToDecimal(1.234567890123465E+17R) & vbCrLf   ' Displays 1234568000

outputBlock.Text &= Convert.ToDecimal(10030.12345678905R) & vbCrLf       ' Displays 10030.123456789 
outputBlock.Text &= Convert.ToDecimal(10030.12345678915R) & vbCrLf       ' Displays 10030.1234567892

outputBlock.Text += Convert.ToDecimal(123456789012345500.12D) + "\n";  // Displays 1234568000
outputBlock.Text += Convert.ToDecimal(123456789012346500.12D) + "\n";  // Displays 1234568000

outputBlock.Text += Convert.ToDecimal(10030.12345678905D) + "\n";      // Displays 10030.123456789 
outputBlock.Text += Convert.ToDecimal(10030.12345678915D) + "\n";      // Displays 10030.1234567892

Examples

The following example uses the ToDecimal(Double) method to convert a Double value to a Decimal value.

Public Sub ConvertDoubleDecimal(ByVal decimalVal As Decimal)

   Dim doubleVal As Double

   ' Decimal to Double conversion cannot overflow.
   doubleVal = System.Convert.ToDouble(decimalVal)
   outputBlock.Text &= String.Format("{0} as a Double is: {1}", _
                            decimalVal, doubleVal) & vbCrLf

   ' Conversion from Double to Decimal can overflow.
   Try
      decimalVal = System.Convert.ToDecimal(doubleVal)
      outputBlock.Text &= String.Format("{0} as a Decimal is: {1}", _
                               doubleVal, decimalVal) & vbCrLf
   Catch exception As System.OverflowException
      outputBlock.Text &= String.Format( _
          "Overflow in Double-to-Decimal conversion.") & vbCrLf
   End Try

End Sub

public void ConvertDoubleDecimal(decimal decimalVal)
{
   double doubleVal;

   // Decimal to double conversion cannot overflow.
   doubleVal = System.Convert.ToDouble(decimalVal);
   outputBlock.Text += String.Format("{0} as a double is: {1}",
         decimalVal, doubleVal) + "\n";

   // Conversion from double to decimal can overflow.
   try
   {
      decimalVal = System.Convert.ToDecimal(doubleVal);
      outputBlock.Text += String.Format("{0} as a decimal is: {1}",
         doubleVal, decimalVal) + "\n";
   }
   catch (System.OverflowException)
   {
      outputBlock.Text += String.Format(
         "Overflow in double-to-double conversion.") + "\n";
   }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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