Buffer Classe

Définition

Espace de noms:

System

Assembly:

System.Runtime.dll

Source:

Buffer.cs

Manipule les tableaux de types primitifs.

public ref class Buffer abstract sealed

public static class Buffer

type Buffer = class

Public Class Buffer

Héritage

Object

Buffer

Exemples

L’exemple de code suivant illustre l’utilisation de plusieurs Buffer méthodes de classe.

// Example of the Buffer class methods.
using namespace System;

// Display the array elements from right to left in hexadecimal.
void DisplayArray( array<short>^arr )
{
   Console::Write( "  arr:" );
   for ( int loopX = arr->Length - 1; loopX >= 0; loopX-- )
      Console::Write( " {0:X4}", arr[ loopX ] );
   Console::WriteLine();
}

int main()
{
   
   // This array is to be modified and displayed.
   array<short>^arr = {258,259,260,261,262,263,264,265,266,267,268,269,270,271};
   Console::WriteLine( "This example of the Buffer class "
   "methods generates the following output.\n"
   "Note: The array is displayed from right to left.\n" );
   Console::WriteLine( "Initial values of array:\n" );
   
   // Display the initial array values and ByteLength.
   DisplayArray( arr );
   Console::WriteLine( "\nBuffer::ByteLength( arr ): {0}", Buffer::ByteLength( arr ) );
   
   // Copy a region of the array; set a byte within the array.
   Console::WriteLine( "\nCall these methods: \n"
   "  Buffer::BlockCopy( arr, 5, arr, 16, 9 ),\n"
   "  Buffer::SetByte( arr, 7, 170 ).\n" );
   Buffer::BlockCopy( arr, 5, arr, 16, 9 );
   Buffer::SetByte( arr, 7, 170 );
   
   // Display the array and a byte within the array.
   Console::WriteLine( "Final values of array:\n" );
   DisplayArray( arr );
   Console::WriteLine( "\nBuffer::GetByte( arr, 26 ): {0}", Buffer::GetByte( arr, 26 ) );
}

/*
This example of the Buffer class methods generates the following output.
Note: The array is displayed from right to left.

Initial values of array:

  arr: 010F 010E 010D 010C 010B 010A 0109 0108 0107 0106 0105 0104 0103 0102

Buffer::ByteLength( arr ): 28

Call these methods:
  Buffer::BlockCopy( arr, 5, arr, 16, 9 ),
  Buffer::SetByte( arr, 7, 170 ).

Final values of array:

  arr: 010F 0101 0801 0701 0601 0501 0109 0108 0107 0106 AA05 0104 0103 0102

Buffer::GetByte( arr, 26 ): 15
*/

// Example of the Buffer class methods.
using System;

class BufferClassDemo
{
    // Display the array elements from right to left in hexadecimal.
    public static void DisplayArray( short[ ] arr )
    {
        Console.Write( "  arr:" );
        for( int loopX = arr.Length - 1; loopX >= 0; loopX-- )
            Console.Write( " {0:X4}", arr[ loopX ] );
        Console.WriteLine( );
    }

    public static void Main( )
    {
        // This array is to be modified and displayed.
        short[ ] arr = { 258, 259, 260, 261, 262, 263, 264,
                         265, 266, 267, 268, 269, 270, 271 };

        Console.WriteLine( "This example of the Buffer class " +
            "methods generates the following output.\n" +
            "Note: The array is displayed from right to left.\n" );
        Console.WriteLine( "Initial values of array:\n" );

        // Display the initial array values and ByteLength.
        DisplayArray( arr );
        Console.WriteLine( "\nBuffer.ByteLength( arr ): {0}",
            Buffer.ByteLength( arr ) );

        // Copy a region of the array; set a byte within the array.
        Console.WriteLine( "\nCall these methods: \n" +
            "  Buffer.BlockCopy( arr, 5, arr, 16, 9 ),\n" +
            "  Buffer.SetByte( arr, 7, 170 ).\n" );

        Buffer.BlockCopy( arr, 5, arr, 16, 9 );
        Buffer.SetByte( arr, 7, 170 );

        // Display the array and a byte within the array.
        Console.WriteLine( "Final values of array:\n" );
        DisplayArray( arr );
        Console.WriteLine( "\nBuffer.GetByte( arr, 26 ): {0}",
            Buffer.GetByte( arr, 26 ) );
    }
}

/*
This example of the Buffer class methods generates the following output.
Note: The array is displayed from right to left.

Initial values of array:

  arr: 010F 010E 010D 010C 010B 010A 0109 0108 0107 0106 0105 0104 0103 0102

Buffer.ByteLength( arr ): 28

Call these methods:
  Buffer.BlockCopy( arr, 5, arr, 16, 9 ),
  Buffer.SetByte( arr, 7, 170 ).

Final values of array:

  arr: 010F 0101 0801 0701 0601 0501 0109 0108 0107 0106 AA05 0104 0103 0102

Buffer.GetByte( arr, 26 ): 15
*/

open System

// Display the array elements from right to left in hexadecimal.
let displayArray (arr: int16 []) =
    printf "  arr:"
    for i = arr.Length - 1 downto 0 do
        printf $" {arr[i]:X4}"
    printfn ""

// This array is to be modified and displayed.
let arr = 
    [| 258s; 259s; 260s; 261s; 262s; 263s; 264s
       265s; 266s; 267s; 268s; 269s; 270s; 271s |]

printfn "This example of the Buffer class methods generates the following output.\nNote: The array is displayed from right to left.\n"
printfn "Initial values of array:\n"

// Display the initial array values and ByteLength.
displayArray arr
printfn $"\nBuffer.ByteLength(arr): {Buffer.ByteLength arr}"

// Copy a region of the array; set a byte within the array.
printfn "\nCall these methods: \n  Buffer.BlockCopy(arr, 5, arr, 16, 9),\n  Buffer.SetByte(arr, 7, 170).\n"

Buffer.BlockCopy(arr, 5, arr, 16, 9)
Buffer.SetByte(arr, 7, 170uy)

// Display the array and a byte within the array.
printfn "Final values of array:\n"
displayArray arr
printfn $"\nBuffer.GetByte(arr, 26): {Buffer.GetByte(arr, 26)}"


// This example of the Buffer class methods generates the following output.
// Note: The array is displayed from right to left.
//
// Initial values of array:
//
//   arr: 010F 010E 010D 010C 010B 010A 0109 0108 0107 0106 0105 0104 0103 0102
//
// Buffer.ByteLength(arr): 28
//
// Call these methods:
//   Buffer.BlockCopy(arr, 5, arr, 16, 9),
//   Buffer.SetByte(arr, 7, 170).
//
// Final values of array:
//
//   arr: 010F 0101 0801 0701 0601 0501 0109 0108 0107 0106 AA05 0104 0103 0102
//
// Buffer.GetByte(arr, 26): 15

' Example of the Buffer class methods.
Module BufferClassDemo

    ' Display the array elements from right to left in hexadecimal.
    Sub DisplayArray( arr( ) As Short )

        Console.Write( "  arr:" )
        Dim loopX     As Integer
        For loopX = arr.Length - 1 To 0 Step -1
            Console.Write( " {0:X4}", arr( loopX ) )
        Next loopX
        Console.WriteLine( )
    End Sub

    Sub Main( )

        ' This array is to be modified and displayed.
        Dim arr( ) As Short = { 258, 259, 260, 261, 262, 263, 264, _
                                265, 266, 267, 268, 269, 270, 271 }
        Console.WriteLine( _
            "This example of the Buffer class methods generates " & _
            "the following output." & vbCrLf & "Note: The " & _
            "array is displayed from right to left." & vbCrLf )
        Console.WriteLine( "Initial values of array:" & vbCrLf )

        ' Display the initial array values and ByteLength.
        DisplayArray( arr )
        Console.WriteLine( vbCrLf & _
            "Buffer.ByteLength( arr ): {0}", _
            Buffer.ByteLength( arr ) )

        ' Copy a region of the array; set a byte within the array.
        Console.WriteLine( vbCrLf & _
            "Call these methods: " & vbCrLf & _
            "  Buffer.BlockCopy( arr, 5, arr, 16, 9 )," & vbCrLf & _
            "  Buffer.SetByte( arr, 7, 170 )." & vbCrLf )

        Buffer.BlockCopy( arr, 5, arr, 16, 9 )
        Buffer.SetByte( arr, 7, 170 )

        ' Display the array and a byte within the array.
        Console.WriteLine( "Final values of array:" & vbCrLf )
        DisplayArray( arr )
        Console.WriteLine( vbCrLf & _
            "Buffer.GetByte( arr, 26 ): {0}", _
            Buffer.GetByte( arr, 26 ) )
    End Sub 
End Module 

' This example of the Buffer class methods generates the following output.
' Note: The array is displayed from right to left.
' 
' Initial values of array:
' 
'   arr: 010F 010E 010D 010C 010B 010A 0109 0108 0107 0106 0105 0104 0103 0102
' 
' Buffer.ByteLength( arr ): 28
' 
' Call these methods:
'   Buffer.BlockCopy( arr, 5, arr, 16, 9 ),
'   Buffer.SetByte( arr, 7, 170 ).
' 
' Final values of array:
' 
'   arr: 010F 0101 0801 0701 0601 0501 0109 0108 0107 0106 AA05 0104 0103 0102
' 
' Buffer.GetByte( arr, 26 ): 15

Remarques

Buffer affecte uniquement les tableaux de types primitifs ; cette classe ne s’applique pas aux objets. Chaque type primitif est traité comme une série d’octets sans tenir compte de tout comportement ou limitation associé au type primitif.

Buffer fournit des méthodes permettant de copier des octets d’un tableau de types primitifs vers un autre tableau de types primitifs, d’obtenir un octet à partir d’un tableau, de définir un octet dans un tableau et d’obtenir la longueur d’un tableau. Cette classe fournit de meilleures performances pour la manipulation de types primitifs que les méthodes similaires dans la System.Array classe .

Buffers’applique aux types primitifs suivants : Boolean, Char, ByteSByte, Int16, UInt16, Int32IntPtrUInt32UInt64UIntPtrInt64, Single, et .Double

Méthodes

BlockCopy(Array, Int32, Array, Int32, Int32)	Copie un nombre spécifié d'octets à partir d'un tableau source en commençant à un offset particulier vers un tableau de destination commençant à un offset donné.
ByteLength(Array)	Retourne le nombre d'octets dans le tableau spécifié.
GetByte(Array, Int32)	Récupère l’octet à l’emplacement spécifié du tableau spécifié.
MemoryCopy(Void*, Void*, Int64, Int64)	Copie un nombre d’octets spécifié en tant que valeur de type Entier long d’une adresse mémoire vers une autre. Cette API n’est pas conforme CLS.
MemoryCopy(Void*, Void*, UInt64, UInt64)	Copie un nombre d’octets spécifié en tant qu’entier long non signé depuis une adresse mémoire vers une autre. Cette API n’est pas conforme CLS.
SetByte(Array, Int32, Byte)	Assigne une valeur spécifiée à un octet à un emplacement particulier dans un tableau spécifié.