Buffer.GetByte Method (Array, Int32)

 

Retrieves the byte at a specified location in a specified array.

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

Public Shared Function GetByte (
	array As Array,
	index As Integer
) As Byte

Parameters

array
Type: System.Array

An array.

index
Type: System.Int32

A location in the array.

Return Value

Type: System.Byte

Returns the index byte in the array.

Exception Condition
ArgumentException

array is not a primitive.

ArgumentNullException

array is null.

ArgumentOutOfRangeException

index is negative or greater than the length of array.

OverflowException

array is larger than 2 gigabytes (GB).

The GetByte method gets a particular byte out of the array. The array must be an array of primitives.

The following code example displays the byte values at specified locations within arrays using the GetByte method.

' Example of the Buffer.GetByte method.
Imports System
Imports Microsoft.VisualBasic

Module GetByteDemo

    Const formatter As String = "{0,10}{1,10}{2,9} {3}"

    ' Display the array contents in hexadecimal.
    Sub DisplayArray( arr As Array, name As String )

        ' Get the array element width; format the formatting string.
        Dim loopX     As Integer
        Dim elemWidth As Integer = _
            Buffer.ByteLength( arr ) / arr.Length
        Dim format    As String = _
            String.Format( " {{0:X{0}}}", 2 * elemWidth )

        ' Display the array elements from right to left.
        Console.Write( "{0,7}:", name )
        For loopX = arr.Length - 1 to 0 Step -1
            Console.Write( format, arr( loopX ) )
        Next loopX
        Console.WriteLine( )
    End Sub

    Sub ArrayInfo( arr As Array, name As String, index As Integer )

        Dim value As Byte = Buffer.GetByte( arr, index )

        ' Display the array name, index, and byte to be viewed.
        Console.WriteLine( formatter, name, index, value, _
            String.Format( "&H{0:X2}", value ) )
    End Sub

    Sub Main( )

        ' These are the arrays to be viewed with GetByte.
        Dim longs( ) As Long  = _
            { 333333333333333333, 666666666666666666, 999999999999999999 }
        Dim ints( )  As Integer = _
            { 111111111, 222222222, 333333333, 444444444, 555555555 }

        Console.WriteLine( "This example of the " & _
            "Buffer.GetByte( Array, Integer ) " & vbCrLf & _
            "method generates the following output." & vbCrLf & _
            "Note: The arrays are displayed from right to left." )
        Console.WriteLine( vbCrLf & "  Values of arrays:" & vbCrLf )

        ' Display the values of the arrays.
        DisplayArray( longs, "longs" )
        DisplayArray( ints, "ints" )
        Console.WriteLine( )

        Console.WriteLine( formatter, "Array", "index", _
            "value", "" )
        Console.WriteLine( formatter, "-----", "-----", _
            "-----", "----" )

        ' Display the Length and ByteLength for each array.
        ArrayInfo( ints, "ints", 0 )
        ArrayInfo( ints, "ints", 7 )
        ArrayInfo( ints, "ints", 10 )
        ArrayInfo( ints, "ints", 17 )
        ArrayInfo( longs, "longs", 0 )
        ArrayInfo( longs, "longs", 6 )
        ArrayInfo( longs, "longs", 10 )
        ArrayInfo( longs, "longs", 17 )
        ArrayInfo( longs, "longs", 21 )
    End Sub 
End Module 

' This example of the Buffer.GetByte( Array, Integer )
' method generates the following output.
' Note: The arrays are displayed from right to left.
' 
'   Values of arrays:
' 
'   longs: 0DE0B6B3A763FFFF 094079CD1A42AAAA 04A03CE68D215555
'    ints: 211D1AE3 1A7DAF1C 13DE4355 0D3ED78E 069F6BC7
' 
'      Array     index    value
'      -----     -----    ----- ----
'       ints         0      199 &HC7
'       ints         7       13 &H0D
'       ints        10      222 &HDE
'       ints        17       26 &H1A
'      longs         0       85 &H55
'      longs         6      160 &HA0
'      longs        10       66 &H42
'      longs        17      255 &HFF
'      longs        21      182 &HB6

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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