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ToUInt64 Method

BitConverter.ToUInt64 Method

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

This API is not CLS-compliant. 

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

'Declaration
<CLSCompliantAttribute(False)> _
Public Shared Function ToUInt64 ( _
	value As Byte(), _
	startIndex As Integer _
) As ULong
'Usage
Dim value As Byte()
Dim startIndex As Integer 
Dim returnValue As ULong 

returnValue = BitConverter.ToUInt64(value, _
	startIndex)

Parameters

value
Type: System.Byte()

An array of bytes.

startIndex
Type: System.Int32

The starting position within value.

Return Value

Type: System.UInt64
A 64-bit unsigned integer formed by the 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 Nothing.

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. 
Imports System
Imports Microsoft.VisualBasic

Module BytesToUInt64Demo

    Const formatter As String = "{0,5}{1,27}{2,24}" 

    ' Convert eight Byte array elements to a UInt64 and display it. 
    Sub BAToUInt64( bytes( ) As Byte, index As Integer )

        Dim value As UInt64 = BitConverter.ToUInt64( bytes, index )

        Console.WriteLine( formatter, index, _
            BitConverter.ToString( bytes, index, 8 ), value )
    End Sub  

    ' Display a Byte array, using multiple lines if necessary. 
    Sub WriteMultiLineByteArray( bytes( ) As Byte )

        Const rowSize As Integer = 20 
        Dim iter As Integer

        Console.WriteLine( "initial Byte array" )
        Console.WriteLine( "------------------" )

        For iter = 0 To bytes.Length - rowSize - 1 Step rowSize
            Console.Write( _
                BitConverter.ToString( bytes, iter, rowSize ) )
            Console.WriteLine( "-" )
        Next iter

        Console.WriteLine( BitConverter.ToString( bytes, iter ) )
        Console.WriteLine( )
    End Sub 

    Sub Main( )
        Dim byteArray as Byte( ) = { _
            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( ), " & _
            "Integer ) " & vbCrLf & "method generates the " & _
            "following output. It converts elements " & vbCrLf & _
            "of a Byte array to UInt64 values." & vbCrLf )

        WriteMultiLineByteArray( byteArray )

        Console.WriteLine( formatter, "index", "array elements", _
            "UInt64" )
        Console.WriteLine( formatter, "-----", "--------------", _
            "------" )

        ' Convert Byte array elements to UInt64 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 )
    End Sub  
End Module 

' This example of the BitConverter.ToUInt64( Byte( ), Integer ) 
' method generates the following output. It converts elements 
' of a Byte array to UInt64 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                  UInt64 
' -----             --------------                  ------ 
'     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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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