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BitConverter.ToInt64 Method

Returns a 64-bit signed integer converted from eight bytes at a specified position in a byte array.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
[SecuritySafeCriticalAttribute]
public static long ToInt64(
	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.Int64
A 64-bit signed integer 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 Int64 values with the ToInt64 method.


// Example of the BitConverter.ToInt64 method.
using System;

class Example
{
   const string formatter = "{0,5}{1,27}{2,24}";

   // Convert eight byte array elements to a long and display it.
   public static void BAToInt64(System.Windows.Controls.TextBlock outputBlock, byte[] bytes, int index)
   {
      long value = BitConverter.ToInt64(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,  54, 101, 196, 255, 255, 255, 255,   0,   0,
              0,   0,   0,   0,   0,   0, 128,   0, 202, 154, 
             59,   0,   0,   0,   0,   1,   0,   0,   0,   0, 
            255, 255, 255, 255,   1,   0,   0, 255, 255, 255, 
            255, 255, 255, 255, 127,  86,  85,  85,  85,  85, 
             85, 255, 255, 170, 170, 170, 170, 170, 170,   0, 
              0, 100, 167, 179, 182, 224,  13,   0,   0, 156, 
             88,  76,  73,  31, 242 };

      outputBlock.Text += String.Format(
          "This example of the BitConverter.ToInt64( byte[ ], " +
          "int ) \nmethod generates the following output. It " +
          "converts elements \nof a byte array to long values.\r\n") + "\n";

      WriteMultiLineByteArray(outputBlock, byteArray);

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

      // Convert byte array elements to long values.
      BAToInt64(outputBlock, byteArray, 8);
      BAToInt64(outputBlock, byteArray, 5);
      BAToInt64(outputBlock, byteArray, 34);
      BAToInt64(outputBlock, byteArray, 17);
      BAToInt64(outputBlock, byteArray, 0);
      BAToInt64(outputBlock, byteArray, 21);
      BAToInt64(outputBlock, byteArray, 26);
      BAToInt64(outputBlock, byteArray, 53);
      BAToInt64(outputBlock, byteArray, 45);
      BAToInt64(outputBlock, byteArray, 59);
      BAToInt64(outputBlock, byteArray, 67);
      BAToInt64(outputBlock, byteArray, 37);
      BAToInt64(outputBlock, byteArray, 9);
   }
}

/*
This example of the BitConverter.ToInt64( byte[ ], int )
method generates the following output. It converts elements
of a byte array to long values.

initial byte array
------------------
00-36-65-C4-FF-FF-FF-FF-00-00-00-00-00-00-00-00-80-00-CA-9A-
3B-00-00-00-00-01-00-00-00-00-FF-FF-FF-FF-01-00-00-FF-FF-FF-
FF-FF-FF-FF-7F-56-55-55-55-55-55-FF-FF-AA-AA-AA-AA-AA-AA-00-
00-64-A7-B3-B6-E0-0D-00-00-9C-58-4C-49-1F-F2

index             array elements                    long
-----             --------------                    ----
    8    00-00-00-00-00-00-00-00                       0
    5    FF-FF-FF-00-00-00-00-00                16777215
   34    01-00-00-FF-FF-FF-FF-FF               -16777215
   17    00-CA-9A-3B-00-00-00-00              1000000000
    0    00-36-65-C4-FF-FF-FF-FF             -1000000000
   21    00-00-00-00-01-00-00-00              4294967296
   26    00-00-00-00-FF-FF-FF-FF             -4294967296
   53    AA-AA-AA-AA-AA-AA-00-00         187649984473770
   45    56-55-55-55-55-55-FF-FF        -187649984473770
   59    00-00-64-A7-B3-B6-E0-0D     1000000000000000000
   67    00-00-9C-58-4C-49-1F-F2    -1000000000000000000
   37    FF-FF-FF-FF-FF-FF-FF-7F     9223372036854775807
    9    00-00-00-00-00-00-00-80    -9223372036854775808
*/


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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