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BitConverter.ToDouble Method

.NET Framework 3.0
Returns a double-precision floating point number converted from eight bytes at a specified position in a byte array.

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

C#
C++
VB
Copy 
public static double ToDouble (
	byte[] value,
	int startIndex
)
J#
Copy 
public static double ToDouble (
	byte[] value, 
	int startIndex
)
JScript
Copy 
public static function ToDouble (
	value : byte[], 
	startIndex : int
) : double
XAML
Copy 
Not applicable.

Parameters

value

An array of bytes.

startIndex

The starting position within value.

Return Value

A double precision floating point number formed by eight bytes beginning at startIndex.
Exception typeCondition

ArgumentException

startIndex is greater than or equal to the length of value minus 7, and is less than or equal to the length of value minus 1.

ArgumentNullException

value is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

startIndex is less than zero or greater than the length of value minus 1.

The following code example converts elements of Byte arrays to Double values with the ToDouble method.

C#
C++
VB
Copy 
// Example of the BitConverter.ToDouble method.
using System;

class BytesToDoubleDemo
{
    const string formatter = "{0,5}{1,27}{2,27:E16}";
 
    // Convert eight byte array elements to a double and display it.
    public static void BAToDouble( byte[ ] bytes, int index )
    {
        double value = BitConverter.ToDouble( bytes, index );

        Console.WriteLine( formatter, index, 
            BitConverter.ToString( bytes, index, 8 ), value );
    }

    // Display a byte array, using multiple lines if necessary.
    public static void WriteMultiLineByteArray( byte[ ] bytes )
    {
        const int rowSize = 20;
        int iter;

        Console.WriteLine( "initial byte array" );
        Console.WriteLine( "------------------" );

        for( iter = 0; iter < bytes.Length - rowSize; iter += rowSize )
        {
            Console.Write( 
                BitConverter.ToString( bytes, iter, rowSize ) );
            Console.WriteLine( "-" );
        }

        Console.WriteLine( BitConverter.ToString( bytes, iter ) );
        Console.WriteLine( );
    }

    public static void Main( )
    {
        byte[ ] byteArray = {
              0,   0,   0,   0,   0,   0,   0,   0, 240,  63, 
              0,   0,   0,   0,   0, 224, 111,  64,   0,   0, 
            224, 255, 255, 255, 239,  65,   0,   0,   0,   0, 
              0,   0, 112,  63,   0,   0,   0,   0,   0,   0, 
            240,  61, 223, 136,  30,  28, 254, 116, 170,   1, 
            250,  89, 140,  66, 202, 192, 243,  63, 251,  89, 
            140,  66, 202, 192, 243,  63, 252,  89, 140,  66, 
            202, 192, 243,  63,  82, 211, 187, 188, 232, 126, 
             61, 126, 255, 255, 255, 255, 255, 255, 239, 255, 
            255, 255, 255, 255, 255, 239, 127,   1,   0,   0, 
              0,   0,   0,   0,   0, 248, 255,   0,   0,   0, 
              0,   0,   0, 240, 255,   0,   0,   0,   0,   0, 
              0, 240, 127 };

        Console.WriteLine( 
            "This example of the BitConverter.ToDouble( byte[ ], " +
            "int ) \nmethod generates the following output. It " +
            "converts elements \nof a byte array to double values.\n" );

        WriteMultiLineByteArray( byteArray );

        Console.WriteLine( formatter, "index", "array elements", 
            "double" );
        Console.WriteLine( formatter, "-----", "--------------", 
            "------" );
          
        // Convert byte array elements to double values.
        BAToDouble( byteArray, 0 );
        BAToDouble( byteArray, 2 );
        BAToDouble( byteArray, 10 );
        BAToDouble( byteArray, 18 );
        BAToDouble( byteArray, 26 );
        BAToDouble( byteArray, 34 );
        BAToDouble( byteArray, 42 );
        BAToDouble( byteArray, 50 );
        BAToDouble( byteArray, 58 );
        BAToDouble( byteArray, 66 );
        BAToDouble( byteArray, 74 );
        BAToDouble( byteArray, 82 );
        BAToDouble( byteArray, 89 );
        BAToDouble( byteArray, 97 );
        BAToDouble( byteArray, 99 );
        BAToDouble( byteArray, 107 );
        BAToDouble( byteArray, 115 );
    }
}

/*
This example of the BitConverter.ToDouble( byte[ ], int )
method generates the following output. It converts elements
of a byte array to double values.

initial byte array
------------------
00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
E0-FF-FF-FF-EF-41-00-00-00-00-00-00-70-3F-00-00-00-00-00-00-
F0-3D-DF-88-1E-1C-FE-74-AA-01-FA-59-8C-42-CA-C0-F3-3F-FB-59-
8C-42-CA-C0-F3-3F-FC-59-8C-42-CA-C0-F3-3F-52-D3-BB-BC-E8-7E-
3D-7E-FF-FF-FF-FF-FF-FF-EF-FF-FF-FF-FF-FF-FF-EF-7F-01-00-00-
00-00-00-00-00-F8-FF-00-00-00-00-00-00-F0-FF-00-00-00-00-00-
00-F0-7F

index             array elements                     double
-----             --------------                     ------
    0    00-00-00-00-00-00-00-00    0.0000000000000000E+000
    2    00-00-00-00-00-00-F0-3F    1.0000000000000000E+000
   10    00-00-00-00-00-E0-6F-40    2.5500000000000000E+002
   18    00-00-E0-FF-FF-FF-EF-41    4.2949672950000000E+009
   26    00-00-00-00-00-00-70-3F    3.9062500000000000E-003
   34    00-00-00-00-00-00-F0-3D    2.3283064365386963E-010
   42    DF-88-1E-1C-FE-74-AA-01    1.2345678901234500E-300
   50    FA-59-8C-42-CA-C0-F3-3F    1.2345678901234565E+000
   58    FB-59-8C-42-CA-C0-F3-3F    1.2345678901234567E+000
   66    FC-59-8C-42-CA-C0-F3-3F    1.2345678901234569E+000
   74    52-D3-BB-BC-E8-7E-3D-7E    1.2345678901234569E+300
   82    FF-FF-FF-FF-FF-FF-EF-FF   -1.7976931348623157E+308
   89    FF-FF-FF-FF-FF-FF-EF-7F    1.7976931348623157E+308
   97    01-00-00-00-00-00-00-00    4.9406564584124654E-324
   99    00-00-00-00-00-00-F8-FF                        NaN
  107    00-00-00-00-00-00-F0-FF                  -Infinity
  115    00-00-00-00-00-00-F0-7F                   Infinity
*/
J#
Copy 
// Example of the BitConverter.ToDouble method.
import System.*;

class BytesToDoubleDemo
{
    private static String formatter = "{0,5}{1,27}{2,27:E16}";

    // Convert eight byte array elements to a double and display it.
    public static void BAToDouble(ubyte bytes[], int index)
    {
        double value = BitConverter.ToDouble(bytes, index);
        Console.WriteLine(formatter, (Int32)index, 
            BitConverter.ToString(bytes, index, 8), (System.Double)value);
    } //BAToDouble

    // Display a byte array, using multiple lines if necessary.
    public static void WriteMultiLineByteArray(ubyte bytes[])
    {
        final int rowSize = 20;
        int iter;

        Console.WriteLine("initial byte array");
        Console.WriteLine("------------------");

        for (iter = 0; iter < bytes.length - rowSize; iter+=rowSize) {
            Console.Write(BitConverter.ToString(bytes, iter, rowSize));
            Console.WriteLine("-");
        }
        Console.WriteLine(BitConverter.ToString(bytes, iter));
        Console.WriteLine();
    } //WriteMultiLineByteArray

    public static void main(String[] args)
    {
        ubyte byteArray[] = {
                            0, 0, 0, 0, 0, 0, 0, 0, 240, 63, 0, 0, 0, 0, 0,
                            224, 111, 64, 0, 0, 224, 255, 255, 255, 239, 65,
                            0, 0, 0, 0, 0, 0, 112, 63, 0, 0, 0, 0, 0, 0, 240,
                            61, 223, 136, 30, 28, 254, 116, 170, 1, 250, 89,
                            140, 66, 202, 192, 243, 63, 251, 89, 140, 66, 202,
                            192, 243, 63, 252, 89, 140, 66, 202, 192, 243, 63,
                            82, 211, 187, 188, 232, 126, 61, 126, 255, 255, 255,
                            255, 255, 255, 239, 255,255, 255, 255, 255, 255, 239,
                            127, 1, 0, 0, 0, 0,0, 0, 0, 248, 255, 0, 0, 0, 0, 0,
                            0, 240, 255, 0,0, 0, 0, 0, 0, 240, 127
                            };
        Console.WriteLine("This example of the "
            + "BitConverter.ToDouble( byte[ ], int ) \n"
            + "method generates the following output."  
            + " It converts elements \nof a byte array to double values.\n");
        WriteMultiLineByteArray(byteArray);
        Console.WriteLine(formatter, "index", "array elements", "double");
        Console.WriteLine(formatter, "-----", "--------------", "------");

        // Convert byte array elements to double values.
        BAToDouble(byteArray, 0);
        BAToDouble(byteArray, 2);
        BAToDouble(byteArray, 10);
        BAToDouble(byteArray, 18);
        BAToDouble(byteArray, 26);
        BAToDouble(byteArray, 34);
        BAToDouble(byteArray, 42);
        BAToDouble(byteArray, 50);
        BAToDouble(byteArray, 58);
        BAToDouble(byteArray, 66);
        BAToDouble(byteArray, 74);
        BAToDouble(byteArray, 82);
        BAToDouble(byteArray, 89);
        BAToDouble(byteArray, 97);
        BAToDouble(byteArray, 99);
        BAToDouble(byteArray, 107);
        BAToDouble(byteArray, 115);
    } //main
} //BytesToDoubleDemo

/*
This example of the BitConverter.ToDouble( byte[ ], int )
method generates the following output. It converts elements
of a byte array to double values.

initial byte array
------------------
00-00-00-00-00-00-00-00-F0-3F-00-00-00-00-00-E0-6F-40-00-00-
E0-FF-FF-FF-EF-41-00-00-00-00-00-00-70-3F-00-00-00-00-00-00-
F0-3D-DF-88-1E-1C-FE-74-AA-01-FA-59-8C-42-CA-C0-F3-3F-FB-59-
8C-42-CA-C0-F3-3F-FC-59-8C-42-CA-C0-F3-3F-52-D3-BB-BC-E8-7E-
3D-7E-FF-FF-FF-FF-FF-FF-EF-FF-FF-FF-FF-FF-FF-EF-7F-01-00-00-
00-00-00-00-00-F8-FF-00-00-00-00-00-00-F0-FF-00-00-00-00-00-
00-F0-7F

index             array elements                     double
-----             --------------                     ------
    0    00-00-00-00-00-00-00-00    0.0000000000000000E+000
    2    00-00-00-00-00-00-F0-3F    1.0000000000000000E+000
   10    00-00-00-00-00-E0-6F-40    2.5500000000000000E+002
   18    00-00-E0-FF-FF-FF-EF-41    4.2949672950000000E+009
   26    00-00-00-00-00-00-70-3F    3.9062500000000000E-003
   34    00-00-00-00-00-00-F0-3D    2.3283064365386963E-010
   42    DF-88-1E-1C-FE-74-AA-01    1.2345678901234500E-300
   50    FA-59-8C-42-CA-C0-F3-3F    1.2345678901234565E+000
   58    FB-59-8C-42-CA-C0-F3-3F    1.2345678901234567E+000
   66    FC-59-8C-42-CA-C0-F3-3F    1.2345678901234569E+000
   74    52-D3-BB-BC-E8-7E-3D-7E    1.2345678901234569E+300
   82    FF-FF-FF-FF-FF-FF-EF-FF   -1.7976931348623157E+308
   89    FF-FF-FF-FF-FF-FF-EF-7F    1.7976931348623157E+308
   97    01-00-00-00-00-00-00-00    4.9406564584124654E-324
   99    00-00-00-00-00-00-F8-FF                        NaN
  107    00-00-00-00-00-00-F0-FF                  -Infinity
  115    00-00-00-00-00-00-F0-7F                   Infinity
*/

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

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0
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