ToDouble Method

BitConverter.ToDouble Method

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)

[SecuritySafeCriticalAttribute]
public static double ToDouble(
	byte[] value,
	int startIndex
)

Parameters

value
Type: System.Byte[]
An array of bytes.
startIndex
Type: System.Int32
The starting position within value.

Return Value

Type: System.Double
A double precision floating point number formed by eight bytes beginning at startIndex.

ExceptionCondition
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 null.

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.


// Example of the BitConverter.ToDouble method.
using System;

class Example
{
   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(System.Windows.Controls.TextBlock outputBlock, byte[] bytes, int index)
   {
      double value = BitConverter.ToDouble(bytes, index);

      outputBlock.Text += String.Format(formatter, index,
          BitConverter.ToString(bytes, index, 8), value) + "\n";
   }

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

      outputBlock.Text += "initial byte array" + "\n";
      outputBlock.Text += "------------------" + "\n";

      for (iter = 0; iter < bytes.Length - rowSize; iter += rowSize)
      {
         outputBlock.Text += String.Format(
             BitConverter.ToString(bytes, iter, rowSize));
         outputBlock.Text += "-" + "\n";
      }

      outputBlock.Text += String.Format(BitConverter.ToString(bytes, iter)) + "\n";
      outputBlock.Text += "\n";
   }

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      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 };

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

      WriteMultiLineByteArray(outputBlock, byteArray);

      outputBlock.Text += String.Format(formatter, "index", "array elements",
          "double") + "\n";
      outputBlock.Text += String.Format(formatter, "-----", "--------------",
          "------") + "\n";

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


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

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

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