GZipStream 构造函数

参考

定义

命名空间:: System.IO.Compression

程序集:: System.IO.Compression.dll

程序集:: System.dll

程序集:: netstandard.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

初始化 GZipStream 类的新实例。

重载

GZipStream(Stream, CompressionLevel)	用指定的流和压缩级别初始化 GZipStream 类的新实例。
GZipStream(Stream, CompressionMode)	用指定的流和压缩模式初始化 GZipStream 类的新实例。
GZipStream(Stream, CompressionLevel, Boolean)	使用指定的流和压缩级别，初始化 GZipStream 类的新实例，有选择性的打开流。
GZipStream(Stream, CompressionMode, Boolean)	使用指定的流和压缩模式，初始化 GZipStream 类的新实例，有选择性的打开流。

GZipStream(Stream, CompressionLevel)

Source:: GZipStream.cs

Source:: GZipStream.cs

Source:: GZipStream.cs

用指定的流和压缩级别初始化 GZipStream 类的新实例。

public:
 GZipStream(System::IO::Stream ^ stream, System::IO::Compression::CompressionLevel compressionLevel);

public GZipStream (System.IO.Stream stream, System.IO.Compression.CompressionLevel compressionLevel);

new System.IO.Compression.GZipStream : System.IO.Stream * System.IO.Compression.CompressionLevel -> System.IO.Compression.GZipStream

Public Sub New (stream As Stream, compressionLevel As CompressionLevel)

参数

stream: Stream

压缩数据写入到的流。

compressionLevel: CompressionLevel

枚举值之一，该值指示在将数据压缩到流中时是强调速度还是压缩效率。

例外

ArgumentNullException

stream 为 null。

ArgumentException

流不支持写入操作，如压缩。（流对象上的 CanWrite 属性是 false。）

注解

如果要指定压缩效率还是速度对于类的 GZipStream 实例更重要，请使用此构造函数。

此构造函数重载使用压缩模式 Compress。若要将压缩模式设置为另一个值，请使用 GZipStream(Stream, CompressionMode) 或 GZipStream(Stream, CompressionMode, Boolean) 重载。

适用于

GZipStream(Stream, CompressionMode)

Source:: GZipStream.cs

Source:: GZipStream.cs

Source:: GZipStream.cs

用指定的流和压缩模式初始化 GZipStream 类的新实例。

public:
 GZipStream(System::IO::Stream ^ stream, System::IO::Compression::CompressionMode mode);

public GZipStream (System.IO.Stream stream, System.IO.Compression.CompressionMode mode);

new System.IO.Compression.GZipStream : System.IO.Stream * System.IO.Compression.CompressionMode -> System.IO.Compression.GZipStream

Public Sub New (stream As Stream, mode As CompressionMode)

参数

stream: Stream

压缩数据写入的流或从中读取解压缩数据的流。

mode: CompressionMode

枚举值之一，该值指示是将数据压缩到流中还是从流中解压缩数据。

例外

ArgumentNullException

stream 为 null。

ArgumentException

mode 不是有效的 CompressionMode 枚举值。

- 或 -

CompressionMode 为 Compress，而 CanWrite 为 false。

- 或 -

CompressionMode 为 Decompress，而 CanRead 为 false。

示例

以下示例演示如何在创建 GZipStream 对象时设置压缩模式。

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

public class FileCompressionModeExample
{
    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 const string OriginalFileName = "original.txt";
    private const string CompressedFileName = "compressed.gz";
    private const string DecompressedFileName = "decompressed.txt";

    public static void Run()
    {
        CreateFileToCompress();
        CompressFile();
        DecompressFile();
        PrintResults();
        DeleteFiles();

        /*
         Output:

            The original file 'original.txt' is 445 bytes. Contents: "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."

            The compressed file 'compressed.gz' is 283 bytes.

            The decompressed file 'decompressed.txt' is 445 bytes. Contents: "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 void CreateFileToCompress() => File.WriteAllText(OriginalFileName, Message);

    private static void CompressFile()
    {
        using FileStream originalFileStream = File.Open(OriginalFileName, FileMode.Open);
        using FileStream compressedFileStream = File.Create(CompressedFileName);
        using var compressor = new GZipStream(compressedFileStream, CompressionMode.Compress);
        originalFileStream.CopyTo(compressor);
    }

    private static void DecompressFile()
    {
        using FileStream compressedFileStream = File.Open(CompressedFileName, FileMode.Open);
        using FileStream outputFileStream = File.Create(DecompressedFileName);
        using var decompressor = new GZipStream(compressedFileStream, CompressionMode.Decompress);
        decompressor.CopyTo(outputFileStream);
    }

    private static void PrintResults()
    {
        long originalSize = new FileInfo(OriginalFileName).Length;
        long compressedSize = new FileInfo(CompressedFileName).Length;
        long decompressedSize = new FileInfo(DecompressedFileName).Length;

        Console.WriteLine($"The original file '{OriginalFileName}' is {originalSize} bytes. Contents: \"{File.ReadAllText(OriginalFileName)}\"");
        Console.WriteLine($"The compressed file '{CompressedFileName}' is {compressedSize} bytes.");
        Console.WriteLine($"The decompressed file '{DecompressedFileName}' is {decompressedSize} bytes. Contents: \"{File.ReadAllText(DecompressedFileName)}\"");
    }

    private static void DeleteFiles()
    {
        File.Delete(OriginalFileName);
        File.Delete(CompressedFileName);
        File.Delete(DecompressedFileName);
    }
}

open System.IO
open System.IO.Compression

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 OriginalFileName = "original.txt"
let CompressedFileName = "compressed.gz"
let DecompressedFileName = "decompressed.txt"

let createFileToCompress () =
    File.WriteAllText(OriginalFileName, message)

let compressFile () =
    use originalFileStream = File.Open(OriginalFileName, FileMode.Open)
    use compressedFileStream = File.Create CompressedFileName
    use compressor = new GZipStream(compressedFileStream, CompressionMode.Compress)
    originalFileStream.CopyTo compressor

let decompressFile () =
    use compressedFileStream = File.Open(CompressedFileName, FileMode.Open)
    use outputFileStream = File.Create DecompressedFileName
    use decompressor = new GZipStream(compressedFileStream, CompressionMode.Decompress)
    decompressor.CopyTo outputFileStream

let printResults () =
    let originalSize = FileInfo(OriginalFileName).Length
    let compressedSize = FileInfo(CompressedFileName).Length
    let decompressedSize = FileInfo(DecompressedFileName).Length

    printfn
        $"The original file '{OriginalFileName}' weighs {originalSize} bytes. Contents: \"{File.ReadAllText OriginalFileName}\""

    printfn $"The compressed file '{CompressedFileName}' weighs {compressedSize} bytes."

    printfn
        $"The decompressed file '{DecompressedFileName}' weighs {decompressedSize} bytes. Contents: \"{File.ReadAllText DecompressedFileName}\""

let deleteFiles () =
    File.Delete OriginalFileName
    File.Delete CompressedFileName
    File.Delete DecompressedFileName

createFileToCompress ()
compressFile ()
decompressFile ()
printResults ()
deleteFiles ()

// Output:
//     The original file 'original.txt' weighs 445 bytes. Contents: "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."
//
//     The compressed file 'compressed.gz' weighs 283 bytes.
//
//     The decompressed file 'decompressed.txt' weighs 445 bytes. Contents: "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."

Imports System
Imports System.IO
Imports System.IO.Compression

Public Class FileCompressionModeExample
    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 Const OriginalFileName As String = "original.txt"
    Private Const CompressedFileName As String = "compressed.gz"
    Private Const DecompressedFileName As String = "decompressed.txt"

    Public Shared Sub Main()
        CreateFileToCompress()
        CompressFile()
        DecompressFile()
        PrintResults()
        DeleteFiles()

        ' Output:
        '   The original file 'original.txt' weighs 445 bytes. Contents: "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."

        '   The compressed file 'compressed.gz' weighs 283 bytes.

        '   The decompressed file 'decompressed.txt' weighs 445 bytes. Contents: "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."
    End Sub

    Private Shared Sub CreateFileToCompress()
        File.WriteAllText(OriginalFileName, Message)
    End Sub

    Private Shared Sub CompressFile()
        Using originalFileStream As FileStream = File.Open(OriginalFileName, FileMode.Open)
            Using compressedFileStream As FileStream = File.Create(CompressedFileName)
                Using compressor = New GZipStream(compressedFileStream, CompressionMode.Compress)
                    originalFileStream.CopyTo(compressor)
                End Using
            End Using
        End Using
    End Sub

    Private Shared Sub DecompressFile()
        Using compressedFileStream As FileStream = File.Open(CompressedFileName, FileMode.Open)
            Using outputFileStream As FileStream = File.Create(DecompressedFileName)
                Using decompressor = New GZipStream(compressedFileStream, CompressionMode.Decompress)
                    decompressor.CopyTo(outputFileStream)
                End Using
            End Using
        End Using
    End Sub

    Private Shared Sub PrintResults()
        Dim originalSize As Long = New FileInfo(OriginalFileName).Length
        Dim compressedSize As Long = New FileInfo(CompressedFileName).Length
        Dim decompressedSize As Long = New FileInfo(DecompressedFileName).Length

        Console.WriteLine($"The original file '{OriginalFileName}' weighs {originalSize} bytes. Contents: ""{File.ReadAllText(OriginalFileName)}""")
        Console.WriteLine($"The compressed file '{CompressedFileName}' weighs {compressedSize} bytes.")
        Console.WriteLine($"The decompressed file '{DecompressedFileName}' weighs {decompressedSize} bytes. Contents: ""{File.ReadAllText(DecompressedFileName)}""")
    End Sub

    Private Shared Sub DeleteFiles()
        File.Delete(OriginalFileName)
        File.Delete(CompressedFileName)
        File.Delete(DecompressedFileName)
    End Sub
End Class

注解

默认情况下， GZipStream 拥有基础流，因此关闭 stream 参数也会关闭基础流。请注意，基础流的状态可能会影响流的可用性。此外，不会执行显式检查，因此创建新实例时不会引发其他异常。

如果创建的mode类实例GZipStream的参数等于，Compress并且不执行进一步的操作，则流将显示为有效的空压缩文件。

默认情况下，当压缩模式Compress为时，压缩级别设置为 Optimal 。

适用于

GZipStream(Stream, CompressionLevel, Boolean)

Source:: GZipStream.cs

Source:: GZipStream.cs

Source:: GZipStream.cs

使用指定的流和压缩级别，初始化 GZipStream 类的新实例，有选择性的打开流。

public:
 GZipStream(System::IO::Stream ^ stream, System::IO::Compression::CompressionLevel compressionLevel, bool leaveOpen);

public GZipStream (System.IO.Stream stream, System.IO.Compression.CompressionLevel compressionLevel, bool leaveOpen);

new System.IO.Compression.GZipStream : System.IO.Stream * System.IO.Compression.CompressionLevel * bool -> System.IO.Compression.GZipStream

Public Sub New (stream As Stream, compressionLevel As CompressionLevel, leaveOpen As Boolean)

参数

stream: Stream

压缩数据写入到的流。

compressionLevel: CompressionLevel

枚举值之一，该值指示在将数据压缩到流中时是强调速度还是压缩效率。

leaveOpen: Boolean

如果在释放 GZipStream 对象之后打开流对象，则为 true；否则为 false。

例外

ArgumentNullException

stream 为 null。

ArgumentException

流不支持写入操作，如压缩。（流对象上的 CanWrite 属性是 false。）

示例

以下示例演示如何在创建 GZipStream 对象时设置压缩级别以及如何使流保持打开状态。

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

注解

如果要指定压缩效率还是速度对于类的 GZipStream 实例更重要，以及是否在释放 GZipStream 对象后让流对象保持打开状态，可以使用此构造函数。

适用于

GZipStream(Stream, CompressionMode, Boolean)

Source:: GZipStream.cs

Source:: GZipStream.cs

Source:: GZipStream.cs

使用指定的流和压缩模式，初始化 GZipStream 类的新实例，有选择性的打开流。

public:
 GZipStream(System::IO::Stream ^ stream, System::IO::Compression::CompressionMode mode, bool leaveOpen);

public GZipStream (System.IO.Stream stream, System.IO.Compression.CompressionMode mode, bool leaveOpen);

new System.IO.Compression.GZipStream : System.IO.Stream * System.IO.Compression.CompressionMode * bool -> System.IO.Compression.GZipStream

Public Sub New (stream As Stream, mode As CompressionMode, leaveOpen As Boolean)

参数

stream: Stream

压缩数据写入的流或从中读取解压缩数据的流。

mode: CompressionMode

枚举值之一，该值指示是将数据压缩到流中还是从流中解压缩数据。

leaveOpen: Boolean

如果在释放 GZipStream 对象之后打开流，则为 true；否则为 false。

例外

ArgumentNullException

stream 为 null。

ArgumentException

mode 不是有效的 CompressionMode 值。

- 或 -

CompressionMode 为 Compress，而 CanWrite 为 false。

- 或 -

CompressionMode 为 Decompress，而 CanRead 为 false。

注解

默认情况下， GZipStream 拥有基础流，因此关闭 stream 参数也会关闭基础流。基础流的状态可能会影响流的可用性。此外，不会执行显式检查，因此创建新实例时不会引发其他异常。

如果创建的mode类实例GZipStream的参数等于，Compress并且不执行进一步的操作，则流将显示为有效的空压缩文件。

默认情况下，当压缩模式Compress为时，压缩级别设置为 Optimal 。

适用于

GZipStream 构造函数

定义

重载

GZipStream(Stream, CompressionLevel)

参数

例外

注解

适用于

GZipStream(Stream, CompressionMode)

参数

例外

示例

注解

适用于

GZipStream(Stream, CompressionLevel, Boolean)

参数

例外

示例

注解

适用于

GZipStream(Stream, CompressionMode, Boolean)

参数

例外

注解

适用于

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