DeflateStream.Read 方法

參考

定義

命名空間:: System.IO.Compression

組件:: System.IO.Compression.dll

組件:: netstandard.dll

組件:: System.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

多載

Read(Span<Byte>)	將位元組序列從目前的 Deflate 資料流程讀取到位元組範圍，並將 Deflate 資料流內位置前移到讀取的位元組數目。
Read(Byte[], Int32, Int32)	將大量解壓縮的位元組讀入指定的位元組陣列。

Read(Span<Byte>)

來源:: DeflateStream.cs

來源:: DeflateStream.cs

來源:: DeflateStream.cs

將位元組序列從目前的 Deflate 資料流程讀取到位元組範圍，並將 Deflate 資料流內位置前移到讀取的位元組數目。

public:
 override int Read(Span<System::Byte> buffer);

public override int Read (Span<byte> buffer);

override this.Read : Span<byte> -> int

Public Overrides Function Read (buffer As Span(Of Byte)) As Integer

參數

buffer: Span<Byte>

記憶體區域。當這個方法傳回時，讀取自目前來源的位元組會取代此區域內容。

傳回

Int32

緩衝區所讀取的總位元組數。如果目前無法取得足夠的位元組，則這個數目可能小於緩衝區所配置的位元組數，如果已經到達資料流末端，則為零 (0)。

備註

重要

從 .NET 6 開始，這個方法可能不會讀取所要求的位元元組數目。如需詳細資訊，請參閱 DeflateStream、GZipStream 和 CryptoStream 中的部分和零位元組讀取。

CanRead使用屬性來判斷目前的實例是否支援讀取。 ReadAsync使用方法，從目前的數據流異步讀取。

這個方法會從目前的數據流讀取最大 buffer.Length 位元組，並將其儲存在 buffer中。 Deflate 數據流中的目前位置會依讀取的位元元組數目進階;不過，如果發生例外狀況，Deflate 數據流中的目前位置會保持不變。如果沒有任何數據可用，這個方法將會封鎖，直到可以讀取至少一個字節的數據為止。 Read 只有在數據流中沒有其他數據，而且預期不會再傳回0 (，例如關閉的套接字或檔案結尾) 。即使尚未到達數據流結尾，方法仍可傳回比要求的位元組少。

用於 BinaryReader 讀取基本數據類型。

適用於

Read(Byte[], Int32, Int32)

來源:: DeflateStream.cs

來源:: DeflateStream.cs

來源:: DeflateStream.cs

將大量解壓縮的位元組讀入指定的位元組陣列。

public:
 override int Read(cli::array <System::Byte> ^ array, int offset, int count);

public:
 override int Read(cli::array <System::Byte> ^ buffer, int offset, int count);

public override int Read (byte[] array, int offset, int count);

public override int Read (byte[] buffer, int offset, int count);

override this.Read : byte[] * int * int -> int

override this.Read : byte[] * int * int -> int

Public Overrides Function Read (array As Byte(), offset As Integer, count As Integer) As Integer

Public Overrides Function Read (buffer As Byte(), offset As Integer, count As Integer) As Integer

參數

arraybuffer: Byte[]

用於儲存解壓縮位元組的陣列。

offset: Int32

將放置讀取位元組的位元移。

count: Int32

要讀取的最大解壓縮位元組數。

傳回

Int32

已讀入至位元組陣列的位元組數。

例外狀況

ArgumentNullException

array 或 buffer 為 null。

InvalidOperationException

建立物件時，CompressionMode 的值為 Compress。

-或-

基礎資料流不支援讀取。

ArgumentOutOfRangeException

offset 或 count 小於零。

-或-

array 或 buffer 長度減去索引起點小於 count。

InvalidDataException

資料的格式無效。

ObjectDisposedException

資料流已關閉。

備註

重要

從 .NET 6 開始，這個方法可能不會讀取所要求的位元元組數目。如需詳細資訊，請參閱 DeflateStream、GZipStream 和 CryptoStream 中的部分和零位元組讀取。

下列範例示範如何使用和 Write 方法來壓縮和解壓縮位元組Read。

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 265 bytes.
            The decompressed string length is 445 bytes, same as the original length.
        */
    }

    private static void CompressBytesToStream(Stream stream)
    {
        using var compressor = new DeflateStream(stream, CompressionMode.Compress, 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 deflateStream = new DeflateStream(stream, CompressionMode.Decompress);

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

        return totalRead;
    }
}

module MemoryWriteReadExample

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 DeflateStream(stream, CompressionMode.Compress, 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 DeflateStream(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 265 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 265 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 DeflateStream(stream, CompressionMode.Compress, 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 DeflateStream(stream, CompressionMode.Decompress)
            Dim length As Integer = decompressor.Read(decompressedBytes, 0, bufferSize)
            Return length
        End Using
    End Function
End Module

適用於

共用方式為

DeflateStream.Read 方法

定義

多載

Read(Span<Byte>)

參數

傳回

備註

適用於

Read(Byte[], Int32, Int32)

參數

傳回

例外狀況

備註

適用於

其他資源