Buffer.BlockCopy(Array, Int32, Array, Int32, Int32) Methode
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Kopieert een opgegeven aantal bytes van een bronmatrix vanaf een bepaalde offset naar een doelmatrix die begint bij een bepaalde offset.
public:
static void BlockCopy(Array ^ src, int srcOffset, Array ^ dst, int dstOffset, int count);public static void BlockCopy(Array src, int srcOffset, Array dst, int dstOffset, int count);static member BlockCopy : Array * int * Array * int * int -> unitPublic Shared Sub BlockCopy (src As Array, srcOffset As Integer, dst As Array, dstOffset As Integer, count As Integer)Parameters
- src
- Array
De bronbuffer.
- srcOffset
- Int32
De byte-offset op basis van nul in src.
- dst
- Array
De doelbuffer.
- dstOffset
- Int32
De byte-offset op basis van nul in dst.
- count
- Int32
Het aantal te kopiëren bytes.
Uitzonderingen
src of dst is null.
src of dst is geen matrix van primitieven.
– of –
Het aantal bytes in src is kleiner dan srcOffset plus count.
– of –
Het aantal bytes in dst is kleiner dan dstOffset plus count.
srcOffset, dstOffsetof count kleiner is dan 0.
Voorbeelden
In het volgende voorbeeld worden regio's met matrices gekopieerd met behulp van de BlockCopy methode. Voor elke BlockCopy bewerking worden de bron- en doelmatrices weergegeven als een matrix met waarden en als een reeks bytes. Het voorbeeld illustreert het belang van het beschouwen van de endianiteit van een systeem bij het werken met de methode BlockCopy: Omdat Windows systemen little-endian zijn, worden de lagere bytes van de waarde van een primitief gegevenstype voorafgegaan door de hogere volgordebytes.
using System;
class Example
{
// Display the individual bytes in the array in hexadecimal.
public static void DisplayArray(Array arr, string name)
{
Console.WindowWidth = 120;
Console.Write("{0,11}:", name);
for (int ctr = 0; ctr < arr.Length; ctr++)
{
byte[] bytes;
if (arr is long[])
bytes = BitConverter.GetBytes((long) arr.GetValue(ctr));
else
bytes = BitConverter.GetBytes((short) arr.GetValue(ctr));
foreach (byte byteValue in bytes)
Console.Write(" {0:X2}", byteValue);
}
Console.WriteLine();
}
// Display the individual array element values in hexadecimal.
public static void DisplayArrayValues(Array arr, string name)
{
// Get the length of one element in the array.
int elementLength = Buffer.ByteLength(arr) / arr.Length;
string formatString = String.Format(" {{0:X{0}}}", 2 * elementLength);
Console.Write( "{0,11}:", name);
for (int ctr = 0; ctr < arr.Length; ctr++)
Console.Write(formatString, arr.GetValue(ctr));
Console.WriteLine();
}
public static void Main( )
{
// These are the source and destination arrays for BlockCopy.
short[] src = { 258, 259, 260, 261, 262, 263, 264,
265, 266, 267, 268, 269, 270 };
long[] dest = { 17, 18, 19, 20 };
// Display the initial value of the arrays in memory.
Console.WriteLine( "Initial values of arrays:");
Console.WriteLine(" Array values as Bytes:");
DisplayArray(src, "src" );
DisplayArray(dest, "dest");
Console.WriteLine(" Array values:");
DisplayArrayValues(src, "src");
DisplayArrayValues(dest, "dest");
Console.WriteLine();
// Copy bytes 5-10 from source to index 7 in destination and display the result.
Buffer.BlockCopy(src, 5, dest, 7, 6);
Console.WriteLine("Buffer.BlockCopy(src, 5, dest, 7, 6 )");
Console.WriteLine(" Array values as Bytes:");
DisplayArray(src, "src");
DisplayArray(dest, "dest");
Console.WriteLine(" Array values:");
DisplayArrayValues(src, "src");
DisplayArrayValues(dest, "dest");
Console.WriteLine();
// Copy bytes 16-20 from source to index 22 in destination and display the result.
Buffer.BlockCopy(src, 16, dest, 22, 5);
Console.WriteLine("Buffer.BlockCopy(src, 16, dest, 22, 5)");
Console.WriteLine(" Array values as Bytes:");
DisplayArray(src, "src");
DisplayArray(dest, "dest");
Console.WriteLine(" Array values:");
DisplayArrayValues(src, "src");
DisplayArrayValues(dest, "dest");
Console.WriteLine();
// Copy overlapping range of bytes 4-10 to index 5 in source.
Buffer.BlockCopy(src, 4, src, 5, 7 );
Console.WriteLine("Buffer.BlockCopy( src, 4, src, 5, 7)");
Console.WriteLine(" Array values as Bytes:");
DisplayArray(src, "src");
DisplayArray(dest, "dest");
Console.WriteLine(" Array values:");
DisplayArrayValues(src, "src");
DisplayArrayValues(dest, "dest");
Console.WriteLine();
// Copy overlapping range of bytes 16-22 to index 15 in source.
Buffer.BlockCopy(src, 16, src, 15, 7);
Console.WriteLine("Buffer.BlockCopy( src, 16, src, 15, 7)");
Console.WriteLine(" Array values as Bytes:");
DisplayArray(src, "src");
DisplayArray(dest, "dest");
Console.WriteLine(" Array values:");
DisplayArrayValues(src, "src");
DisplayArrayValues(dest, "dest");
}
}
// The example displays the following output:
// Initial values of arrays:
// Array values as Bytes:
// src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 00 12 00 00 00 00 00 00 00 13 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00
// Array values:
// src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
// dest: 0000000000000011 0000000000000012 0000000000000013 0000000000000014
//
// Buffer.BlockCopy(src, 5, dest, 7, 6 )
// Array values as Bytes:
// src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00
// Array values:
// src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
// dest: 0100000000000011 0000000701060105 0000000000000013 0000000000000014
//
// Buffer.BlockCopy(src, 16, dest, 22, 5)
// Array values as Bytes:
// src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
// Array values:
// src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
// dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
//
// Buffer.BlockCopy( src, 4, src, 5, 7)
// Array values as Bytes:
// src: 02 01 03 01 04 04 01 05 01 06 01 07 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
// Array values:
// src: 0102 0103 0404 0501 0601 0701 0108 0109 010A 010B 010C 010D 010E
// dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
//
// Buffer.BlockCopy( src, 16, src, 15, 7)
// Array values as Bytes:
// src: 02 01 03 01 04 04 01 05 01 06 01 07 08 01 09 0A 01 0B 01 0C 01 0D 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
// Array values:
// src: 0102 0103 0404 0501 0601 0701 0108 0A09 0B01 0C01 0D01 010D 010E
// dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
open System
// Display the individual bytes in the array in hexadecimal.
let displayArray (arr: 'a []) (name: string) =
Console.WindowWidth <- 120
printf $"%11s{name}:"
for i = 0 to arr.Length - 1 do
let bytes =
match box arr with
| :? array<int64> ->
BitConverter.GetBytes(box arr[i] :?> int64)
| _ ->
BitConverter.GetBytes(box arr[i] :?> int16)
for byteValue in bytes do
printf $" %02X{byteValue}"
printfn ""
// Display the individual array element values in hexadecimal.
let inline displayArrayValues (arr: ^a []) name =
// Get the length of one element in the array.
let elementLength = Buffer.ByteLength arr / arr.Length
printf $"%11s{name}:"
for value in arr do
printf " %0*X" (2 * elementLength) value
printfn ""
// These are the source and destination arrays for BlockCopy.
let src =
[| 258s; 259s; 260s; 261s; 262s; 263s; 264s
265s; 266s; 267s; 268s; 269s; 270s |]
let dest =
[| 17L; 18L; 19L; 20L |]
// Display the initial value of the arrays in memory.
printfn "Initial values of arrays:"
printfn " Array values as Bytes:"
displayArray src "src"
displayArray dest "dest"
printfn " Array values:"
displayArrayValues src "src"
displayArrayValues dest "dest"
printfn ""
// Copy bytes 5-10 from source to index 7 in destination and display the result.
Buffer.BlockCopy(src, 5, dest, 7, 6)
printfn "Buffer.BlockCopy(src, 5, dest, 7, 6 )"
printfn " Array values as Bytes:"
displayArray src "src"
displayArray dest "dest"
printfn " Array values:"
displayArrayValues src "src"
displayArrayValues dest "dest"
printfn ""
// Copy bytes 16-20 from source to index 22 in destination and display the result.
Buffer.BlockCopy(src, 16, dest, 22, 5)
printfn "Buffer.BlockCopy(src, 16, dest, 22, 5)"
printfn " Array values as Bytes:"
displayArray src "src"
displayArray dest "dest"
printfn " Array values:"
displayArrayValues src "src"
displayArrayValues dest "dest"
printfn ""
// Copy overlapping range of bytes 4-10 to index 5 in source.
Buffer.BlockCopy(src, 4, src, 5, 7)
printfn "Buffer.BlockCopy(src, 4, src, 5, 7)"
printfn " Array values as Bytes:"
displayArray src "src"
displayArray dest "dest"
printfn " Array values:"
displayArrayValues src "src"
displayArrayValues dest "dest"
printfn ""
// Copy overlapping range of bytes 16-22 to index 15 in source.
Buffer.BlockCopy(src, 16, src, 15, 7)
printfn "Buffer.BlockCopy(src, 16, src, 15, 7)"
printfn " Array values as Bytes:"
displayArray src "src"
displayArray dest "dest"
printfn " Array values:"
displayArrayValues src "src"
displayArrayValues dest "dest"
// The example displays the following output:
// Initial values of arrays:
// Array values as Bytes:
// src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 00 12 00 00 00 00 00 00 00 13 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00
// Array values:
// src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
// dest: 0000000000000011 0000000000000012 0000000000000013 0000000000000014
//
// Buffer.BlockCopy(src, 5, dest, 7, 6 )
// Array values as Bytes:
// src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00
// Array values:
// src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
// dest: 0100000000000011 0000000701060105 0000000000000013 0000000000000014
//
// Buffer.BlockCopy(src, 16, dest, 22, 5)
// Array values as Bytes:
// src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
// Array values:
// src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
// dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
//
// Buffer.BlockCopy(src, 4, src, 5, 7)
// Array values as Bytes:
// src: 02 01 03 01 04 04 01 05 01 06 01 07 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
// Array values:
// src: 0102 0103 0404 0501 0601 0701 0108 0109 010A 010B 010C 010D 010E
// dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
//
// Buffer.BlockCopy(src, 16, src, 15, 7)
// Array values as Bytes:
// src: 02 01 03 01 04 04 01 05 01 06 01 07 08 01 09 0A 01 0B 01 0C 01 0D 0D 01 0E 01
// dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
// Array values:
// src: 0102 0103 0404 0501 0601 0701 0108 0A09 0B01 0C01 0D01 010D 010E
// dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
Module Example
' Display the individual bytes in the array in hexadecimal.
Sub DisplayArray(arr As Array, name As String)
Console.Write("{0,11}:", name)
For ctr As Integer = 0 to arr.Length - 1
Dim bytes() As Byte = BitConverter.GetBytes(arr(ctr))
For Each byteValue As Byte In bytes
Console.Write(" {0:X2}", byteValue)
Next
Next
Console.WriteLine()
End Sub
' Display the individual array element values in hexadecimal.
Sub DisplayArrayValues(arr As Array, name As String)
' Get the length of one element in the array.
Dim elementLength As Integer = Buffer.ByteLength(arr) / arr.Length
Dim formatString As String = String.Format(" {{0:X{0}}}", 2 * elementLength)
Console.Write("{0,11}:", name)
For ctr As Integer = 0 to arr.Length - 1
Console.Write(formatString, arr(ctr))
Next
Console.WriteLine()
End Sub
Sub Main()
Console.WindowWidth = 120
' These are source and destination arrays for BlockCopy.
Dim src() As Short = { 258, 259, 260, 261, 262, 263, 264, _
265, 266, 267, 268, 269, 270 }
Dim dest() As Long = { 17, 18, 19, 20 }
' Display the initial value of the arrays in memory.
Console.WriteLine( "Initial values of arrays:")
Console.WriteLine(" Array values as Bytes:")
DisplayArray(src, "src" )
DisplayArray(dest, "dest" )
Console.WriteLine(" Array values:")
DisplayArrayValues(src, "src")
DisplayArrayValues(dest, "dest")
Console.WriteLine()
' Copy bytes 5-10 from source to index 7 in destination and display the result.
Buffer.BlockCopy( src, 5, dest, 7, 6 )
Console.WriteLine("Buffer.BlockCopy(src, 5, dest, 7, 6 )")
Console.WriteLine(" Array values as Bytes:")
DisplayArray(src, "src")
DisplayArray(dest, "dest")
Console.WriteLine(" Array values:")
DisplayArrayValues(src, "src")
DisplayArrayValues(dest, "dest")
Console.WriteLine()
' Copy bytes 16-20 from source to index 22 in destination and display the result.
Buffer.BlockCopy( src, 16, dest, 22, 5 )
Console.WriteLine("Buffer.BlockCopy(src, 16, dest, 22, 5)")
Console.WriteLine(" Array values as Bytes:")
DisplayArray(src, "src")
DisplayArray(dest, "dest")
Console.WriteLine(" Array values:")
DisplayArrayValues(src, "src")
DisplayArrayValues(dest, "dest")
Console.WriteLine()
' Copy overlapping range of bytes 4-10 to index 5 in source.
Buffer.BlockCopy( src, 4, src, 5, 7 )
Console.WriteLine("Buffer.BlockCopy( src, 4, src, 5, 7)")
Console.WriteLine(" Array values as Bytes:")
DisplayArray(src, "src")
DisplayArray(dest, "dest")
Console.WriteLine(" Array values:")
DisplayArrayValues(src, "src")
DisplayArrayValues(dest, "dest")
Console.WriteLine()
' Copy overlapping range of bytes 16-22 to index 15 in source.
Buffer.BlockCopy(src, 16, src, 15, 7)
Console.WriteLine("Buffer.BlockCopy( src, 16, src, 15, 7)")
Console.WriteLine(" Array values as Bytes:")
DisplayArray(src, "src")
DisplayArray(dest, "dest")
Console.WriteLine(" Array values:")
DisplayArrayValues(src, "src")
DisplayArrayValues(dest, "dest")
End Sub
End Module
' This example displays the following output:
' Initial values of arrays:
' Array values as Bytes:
' src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
' dest: 11 00 00 00 00 00 00 00 12 00 00 00 00 00 00 00 13 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00
' Array values:
' src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
' dest: 0000000000000011 0000000000000012 0000000000000013 0000000000000014
'
' Buffer.BlockCopy(src, 5, dest, 7, 6 )
' Array values as Bytes:
' src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
' dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00
' Array values:
' src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
' dest: 0100000000000011 0000000701060105 0000000000000013 0000000000000014
'
' Buffer.BlockCopy(src, 16, dest, 22, 5)
' Array values as Bytes:
' src: 02 01 03 01 04 01 05 01 06 01 07 01 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
' dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
' Array values:
' src: 0102 0103 0104 0105 0106 0107 0108 0109 010A 010B 010C 010D 010E
' dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
'
' Buffer.BlockCopy( src, 4, src, 5, 7)
' Array values as Bytes:
' src: 02 01 03 01 04 04 01 05 01 06 01 07 08 01 09 01 0A 01 0B 01 0C 01 0D 01 0E 01
' dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
' Array values:
' src: 0102 0103 0404 0501 0601 0701 0108 0109 010A 010B 010C 010D 010E
' dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
'
' Buffer.BlockCopy( src, 16, src, 15, 7)
' Array values as Bytes:
' src: 02 01 03 01 04 04 01 05 01 06 01 07 08 01 09 0A 01 0B 01 0C 01 0D 0D 01 0E 01
' dest: 11 00 00 00 00 00 00 01 05 01 06 01 07 00 00 00 13 00 00 00 00 00 0A 01 0B 01 0C 00 00 00 00 00
' Array values:
' src: 0102 0103 0404 0501 0601 0701 0108 0A09 0B01 0C01 0D01 010D 010E
' dest: 0100000000000011 0000000701060105 010A000000000013 00000000000C010B
Opmerkingen
Met deze methode worden count bytes gekopieerd van src, beginnend bij srcOffset, naar dst, beginnend bij dstOffset. Beide srcOffset en dstOffset zijn op nul gebaseerd; dat wil gezegd: de eerste byte in elke buffer bevindt zich op positie 0, niet op positie 1.
De BlockCopy methode heeft toegang tot de bytes in de src parametermatrix met behulp van offsets in het geheugen, niet tot programmeerconstructies zoals indexen of boven- en ondermatrixgrenzen. Als u bijvoorbeeld in de programmeertaal van uw toepassing een Int32 matrix declareert met een op nul gebaseerde ondergrens van -50 en vervolgens de matrix en een offset van 5 doorgeeft aan de BlockCopy methode, is het eerste matrixelement dat de methode gebruikt het tweede element van de matrix, dat zich op index -49 bevindt. Bovendien, welke byte van matrixelement -49 eerst wordt geopend, is afhankelijk van de endianiteit van de computer die uw toepassing uitvoert.
Zoals de naam al aangeeft, kopieert de BlockCopy methode een blok bytes als geheel in plaats van één byte tegelijk te kopiëren. Dus als src en dst verwijst naar dezelfde matrix en het bereik vansrcOffset + count -1 overlapt het bereik vandstOffset + count- 1, worden de waarden van de overlappende bytes niet overschreven voordat ze naar het doel worden gekopieerd. In het volgende voorbeeld worden de waarden van bytes 0-16 in een matrix met de naam arr gekopieerd naar bytes 12-28. Ondanks het overlappende bereik worden de waarden van de bronbytes gekopieerd.
const int INT_SIZE = 4;
int[] arr = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
Buffer.BlockCopy(arr, 0 * INT_SIZE, arr, 3 * INT_SIZE, 4 * INT_SIZE);
foreach (int value in arr)
Console.Write("{0} ", value);
// The example displays the following output:
// 2 4 6 2 4 6 8 16 18 20
let intSize = 4
let arr = [| 2; 4; 6; 8; 10; 12; 14; 16; 18; 20 |]
Buffer.BlockCopy(arr, 0 * intSize, arr, 3 * intSize, 4 * intSize)
for value in arr do
printf $"{value} "
// The example displays the following output:
// 2 4 6 2 4 6 8 16 18 20
Const INT_SIZE As Integer = 4
Dim arr() As Integer = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 }
Buffer.BlockCopy(arr, 0 * INT_SIZE, arr, 3 * INT_SIZE, 4 * INT_SIZE)
For Each value As Integer In arr
Console.Write("{0} ", value)
Next
' The example displays the following output:
' 2 4 6 2 4 6 8 16 18 20
In het volgende voorbeeld worden de waarden van bytes 12-28 in een matrix met de naam arr gekopieerd naar bytes 0-16. Nogmaals, ondanks het overlappende bereik, worden de waarden van de bronbytes gekopieerd.
const int INT_SIZE = 4;
int[] arr = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
Buffer.BlockCopy(arr, 3 * INT_SIZE, arr, 0 * INT_SIZE, 4 * INT_SIZE);
foreach (int value in arr)
Console.Write("{0} ", value);
// The example displays the following output:
// 8 10 12 14 10 12 14 16 18 20
let intSize = 4
let arr = [| 2; 4; 6; 8; 10; 12; 14; 16; 18; 20 |]
Buffer.BlockCopy(arr, 3 * intSize, arr, 0 * intSize, 4 * intSize)
for value in arr do
printf $"{value} "
// The example displays the following output:
// 8 10 12 14 10 12 14 16 18 20
Const INT_SIZE As Integer = 4
Dim arr() As Integer = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 }
Buffer.BlockCopy(arr, 3 * INT_SIZE, arr, 0 * INT_SIZE, 4 * INT_SIZE)
For Each value As Integer In arr
Console.Write("{0} ", value)
Next
' The example displays the following output:
' 8 10 12 14 10 12 14 16 18 20
