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GZipStream.Write Metoda

Definice

Přetížení

Write(ReadOnlySpan<Byte>)

Zapíše posloupnost bajtů do aktuálního datového proudu GZip z rozsahu bajtů jen pro čtení a posune aktuální pozici v tomto datovém proudu GZip o počet zapsaných bajtů.

Write(Byte[], Int32, Int32)

Zapíše komprimované bajty do podkladového datového proudu GZip ze zadaného pole bajtů.

Write(ReadOnlySpan<Byte>)

Zdroj:
GZipStream.cs
Zdroj:
GZipStream.cs
Zdroj:
GZipStream.cs

Zapíše posloupnost bajtů do aktuálního datového proudu GZip z rozsahu bajtů jen pro čtení a posune aktuální pozici v tomto datovém proudu GZip o počet zapsaných bajtů.

public:
 override void Write(ReadOnlySpan<System::Byte> buffer);
public override void Write (ReadOnlySpan<byte> buffer);
override this.Write : ReadOnlySpan<byte> -> unit
Public Overrides Sub Write (buffer As ReadOnlySpan(Of Byte))

Parametry

buffer
ReadOnlySpan<Byte>

Oblast paměti. Tato metoda zkopíruje obsah této oblasti do aktuálního datového proudu GZip.

Poznámky

CanWrite Pomocí vlastnosti určete, jestli aktuální instance podporuje zápis. K asynchronnímu zápisu do aktuálního datového WriteAsync proudu použijte metodu .

Pokud je operace zápisu úspěšná, pozice v rámci datového proudu GZip se posune o počet zapsaných bajtů. Pokud dojde k výjimce, zůstane pozice v rámci datového proudu GZip beze změny.

Platí pro

Write(Byte[], Int32, Int32)

Zdroj:
GZipStream.cs
Zdroj:
GZipStream.cs
Zdroj:
GZipStream.cs

Zapíše komprimované bajty do podkladového datového proudu GZip ze zadaného pole bajtů.

public:
 override void Write(cli::array <System::Byte> ^ array, int offset, int count);
public:
 override void Write(cli::array <System::Byte> ^ buffer, int offset, int count);
public override void Write (byte[] array, int offset, int count);
public override void Write (byte[] buffer, int offset, int count);
override this.Write : byte[] * int * int -> unit
override this.Write : byte[] * int * int -> unit
Public Overrides Sub Write (array As Byte(), offset As Integer, count As Integer)
Public Overrides Sub Write (buffer As Byte(), offset As Integer, count As Integer)

Parametry

arraybuffer
Byte[]

Vyrovnávací paměť obsahující data, která se mají komprimovat.

offset
Int32

Odsazení bajtů, ze kterého se bajty budou číst.

count
Int32

Maximální počet bajtů k zápisu.

Výjimky

Operaci zápisu nelze provést, protože datový proud je uzavřen.

Příklady

Následující příklad ukazuje, jak komprimovat a dekomprimovat bajty pomocí Read metod a Write .

using System;
using System.IO;
using System.IO.Compression;
using System.Text;

public static class MemoryWriteReadExample
{
    private const string Message = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";
    private static readonly byte[] s_messageBytes = Encoding.ASCII.GetBytes(Message);

    public static void Run()
    {
        Console.WriteLine($"The original string length is {s_messageBytes.Length} bytes.");
        using var stream = new MemoryStream();
        CompressBytesToStream(stream);
        Console.WriteLine($"The compressed stream length is {stream.Length} bytes.");
        int decompressedLength = DecompressStreamToBytes(stream);
        Console.WriteLine($"The decompressed string length is {decompressedLength} bytes, same as the original length.");
        /*
         Output:
            The original string length is 445 bytes.
            The compressed stream length is 282 bytes.
            The decompressed string length is 445 bytes, same as the original length.
        */
    }

    private static void CompressBytesToStream(Stream stream)
    {
        using var compressor = new GZipStream(stream, CompressionLevel.SmallestSize, leaveOpen: true);
        compressor.Write(s_messageBytes, 0, s_messageBytes.Length);
    }

    private static int DecompressStreamToBytes(Stream stream)
    {
        stream.Position = 0;
        int bufferSize = 512;
        byte[] buffer = new byte[bufferSize];
        using var gzipStream = new GZipStream(stream, CompressionMode.Decompress);

        int totalRead = 0;
        while (totalRead < buffer.Length)
        {
            int bytesRead = gzipStream.Read(buffer.AsSpan(totalRead));
            if (bytesRead == 0) break;
            totalRead += bytesRead;
        }

        return totalRead;
    }
}
open System.IO
open System.IO.Compression
open System.Text

let message =
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."

let s_messageBytes = Encoding.ASCII.GetBytes message

let compressBytesToStream stream =
    use compressor =
        new GZipStream(stream, CompressionLevel.SmallestSize, leaveOpen = true)

    compressor.Write(s_messageBytes, 0, s_messageBytes.Length)

let decompressStreamToBytes (stream: Stream) =
    stream.Position <- 0
    let bufferSize = 512
    let decompressedBytes = Array.zeroCreate bufferSize
    use decompressor = new GZipStream(stream, CompressionMode.Decompress)
    decompressor.Read(decompressedBytes, 0, bufferSize)

[<EntryPoint>]
let main _ =
    printfn $"The original string length is {s_messageBytes.Length} bytes."
    use stream = new MemoryStream()
    compressBytesToStream stream
    printfn $"The compressed stream length is {stream.Length} bytes."
    let decompressedLength = decompressStreamToBytes stream
    printfn $"The decompressed string length is {decompressedLength} bytes, same as the original length."
    0

// Output:
//     The original string length is 445 bytes.
//     The compressed stream length is 282 bytes.
//     The decompressed string length is 445 bytes, same as the original length.
Imports System.IO
Imports System.IO.Compression
Imports System.Text

Module MemoryWriteReadExample
    Private Const Message As String = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
    Private ReadOnly s_messageBytes As Byte() = Encoding.ASCII.GetBytes(Message)

    Sub Main()
        Console.WriteLine($"The original string length is {s_messageBytes.Length} bytes.")

        Using stream = New MemoryStream()
            CompressBytesToStream(stream)
            Console.WriteLine($"The compressed stream length is {stream.Length} bytes.")
            Dim decompressedLength As Integer = DecompressStreamToBytes(stream)
            Console.WriteLine($"The decompressed string length is {decompressedLength} bytes, same as the original length.")
        End Using
        ' Output:
        '   The original string length is 445 bytes.
        '   The compressed stream length is 282 bytes.
        '   The decompressed string length is 445 bytes, same as the original length.
    End Sub

    Private Sub CompressBytesToStream(ByVal stream As Stream)
        Using compressor = New GZipStream(stream, CompressionLevel.SmallestSize, leaveOpen:=True)
            compressor.Write(s_messageBytes, 0, s_messageBytes.Length)
        End Using
    End Sub

    Private Function DecompressStreamToBytes(ByVal stream As Stream) As Integer
        stream.Position = 0
        Dim bufferSize As Integer = 512
        Dim decompressedBytes As Byte() = New Byte(bufferSize - 1) {}
        Using decompressor = New GZipStream(stream, CompressionMode.Decompress)
            Dim length As Integer = decompressor.Read(decompressedBytes, 0, bufferSize)
            Return length
        End Using
    End Function
End Module

Poznámky

Operace zápisu nemusí proběhnout okamžitě, ale je uložena do vyrovnávací paměti, dokud není dosaženo velikosti vyrovnávací paměti nebo dokud Flush není volána metoda nebo Close .

Platí pro