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BitConverter.ToUInt64 Method

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

This method is not CLS-compliant.  

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

[CLSCompliantAttribute(false)] 
public static ulong ToUInt64 (
	byte[] value,
	int startIndex
)
/** @attribute CLSCompliantAttribute(false) */ 
public static UInt64 ToUInt64 (
	byte[] value, 
	int startIndex
)
CLSCompliantAttribute(false) 
public static function ToUInt64 (
	value : byte[], 
	startIndex : int
) : ulong
Not applicable.

Parameters

value

An array of bytes.

startIndex

The starting position within value.

Return Value

A 64-bit unsigned integer formed by the 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 UInt64 values with the ToUInt64 method.

// Example of the BitConverter.ToUInt64 method.
using System;

class BytesToUInt64Demo
{
    const string formatter = "{0,5}{1,27}{2,24}";
 
    // Convert eight byte array elements to a ulong and display it.
    public static void BAToUInt64( byte[ ] bytes, int index )
    {
        ulong value = BitConverter.ToUInt64( 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 = {
            255, 255, 255,   0,   0,   0,   0,   0,   0,   0, 
              0,   1,   0,   0,   0, 100, 167, 179, 182, 224, 
             13,   0, 202, 154,  59,   0,   0,   0,   0, 170, 
            170, 170, 170, 170, 170,   0,   0, 232, 137,   4, 
             35, 199, 138, 255, 255, 255, 255, 255, 255, 255, 
            255, 127 };

        Console.WriteLine( 
            "This example of the BitConverter.ToUInt64( byte[ ], " +
            "int ) \nmethod generates the following output. It " +
            "converts elements \nof a byte array to ulong values.\n" );

        WriteMultiLineByteArray( byteArray );

        Console.WriteLine( formatter, "index", "array elements", 
            "ulong" );
        Console.WriteLine( formatter, "-----", "--------------", 
            "------" );
          
        // Convert byte array elements to ulong values.
        BAToUInt64( byteArray, 3 );
        BAToUInt64( byteArray, 0 );
        BAToUInt64( byteArray, 21 );
        BAToUInt64( byteArray, 7 );
        BAToUInt64( byteArray, 29 );
        BAToUInt64( byteArray, 13 );
        BAToUInt64( byteArray, 35 );
        BAToUInt64( byteArray, 44 );
        BAToUInt64( byteArray, 43 );
    }
}

/*
This example of the BitConverter.ToUInt64( byte[ ], int )
method generates the following output. It converts elements
of a byte array to ulong values.

initial byte array
------------------
FF-FF-FF-00-00-00-00-00-00-00-00-01-00-00-00-64-A7-B3-B6-E0-
0D-00-CA-9A-3B-00-00-00-00-AA-AA-AA-AA-AA-AA-00-00-E8-89-04-
23-C7-8A-FF-FF-FF-FF-FF-FF-FF-FF-7F

index             array elements                   ulong
-----             --------------                  ------
    3    00-00-00-00-00-00-00-00                       0
    0    FF-FF-FF-00-00-00-00-00                16777215
   21    00-CA-9A-3B-00-00-00-00              1000000000
    7    00-00-00-00-01-00-00-00              4294967296
   29    AA-AA-AA-AA-AA-AA-00-00         187649984473770
   13    00-00-64-A7-B3-B6-E0-0D     1000000000000000000
   35    00-00-E8-89-04-23-C7-8A    10000000000000000000
   44    FF-FF-FF-FF-FF-FF-FF-7F     9223372036854775807
   43    FF-FF-FF-FF-FF-FF-FF-FF    18446744073709551615
*/

// Example of the BitConverter.ToUInt64 method.
import System.*;

class BytesToUInt64Demo
{
    private static String formatter = "{0,5}{1,27}{2,24}";

    // Convert eight byte array elements to a ulong and display it.
    public static void BAToUInt64(ubyte bytes[], int index)
    {
        UInt64 value = BitConverter.ToUInt64(bytes, index);
        Console.WriteLine(formatter, (Int32)index, 
            BitConverter.ToString(bytes, index, 8), (UInt64)value);
    } //BAToUInt64

    // 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[] =  { 
                               255, 255, 255, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 
                               0, 100, 167, 179, 182, 224, 13, 0, 202, 154, 59,
                               0, 0, 0, 0, 170, 170, 170, 170, 170, 170, 0, 0,
                               232, 137, 4, 35, 199, 138, 255, 255, 255, 255,
                               255, 255, 255, 255, 127
                            };

        Console.WriteLine("This example of the "
            + "BitConverter.ToUInt64( byte[ ], int ) \n"
            + "method generates the following output. " 
            + "It converts elements \nof a byte array to ulong values.\n");
        WriteMultiLineByteArray(byteArray);
        Console.WriteLine(formatter, "index", "array elements", "ulong");
        Console.WriteLine(formatter, "-----", "--------------", "------");

        // Convert byte array elements to ulong values.
        BAToUInt64(byteArray, 3);
        BAToUInt64(byteArray, 0);
        BAToUInt64(byteArray, 21);
        BAToUInt64(byteArray, 7);
        BAToUInt64(byteArray, 29);
        BAToUInt64(byteArray, 13);
        BAToUInt64(byteArray, 35);
        BAToUInt64(byteArray, 44);
        BAToUInt64(byteArray, 43);
    } //main
} //BytesToUInt64Demo

/*
This example of the BitConverter.ToUInt64( byte[ ], int )
method generates the following output. It converts elements
of a byte array to ulong values.

initial byte array
------------------
FF-FF-FF-00-00-00-00-00-00-00-00-01-00-00-00-64-A7-B3-B6-E0-
0D-00-CA-9A-3B-00-00-00-00-AA-AA-AA-AA-AA-AA-00-00-E8-89-04-
23-C7-8A-FF-FF-FF-FF-FF-FF-FF-FF-7F

index             array elements                   ulong
-----             --------------                  ------
    3    00-00-00-00-00-00-00-00                       0
    0    FF-FF-FF-00-00-00-00-00                16777215
   21    00-CA-9A-3B-00-00-00-00              1000000000
    7    00-00-00-00-01-00-00-00              4294967296
   29    AA-AA-AA-AA-AA-AA-00-00         187649984473770
   13    00-00-64-A7-B3-B6-E0-0D     1000000000000000000
   35    00-00-E8-89-04-23-C7-8A    10000000000000000000
   44    FF-FF-FF-FF-FF-FF-FF-7F     9223372036854775807
   43    FF-FF-FF-FF-FF-FF-FF-FF    18446744073709551615
*/

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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