DeflateStream Constructors

Reference

Definition

Namespace:: System.IO.Compression

Assembly:: System.IO.Compression.dll

Assembly:: System.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Initializes a new instance of the DeflateStream class.

Overloads

DeflateStream(Stream, CompressionLevel)	Initializes a new instance of the DeflateStream class by using the specified stream and compression level.
DeflateStream(Stream, CompressionMode)	Initializes a new instance of the DeflateStream class by using the specified stream and compression mode.
DeflateStream(Stream, CompressionLevel, Boolean)	Initializes a new instance of the DeflateStream class by using the specified stream and compression level, and optionally leaves the stream open.
DeflateStream(Stream, CompressionMode, Boolean)	Initializes a new instance of the DeflateStream class by using the specified stream and compression mode, and optionally leaves the stream open.
DeflateStream(Stream, ZLibCompressionOptions, Boolean)	Initializes a new instance of the DeflateStream class by using the specified stream, compression options, and optionally leaves the stream open.

Remarks

Using the DeflateStream class to compress a file larger than 4 GB will cause an exception.

DeflateStream(Stream, CompressionLevel)

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Initializes a new instance of the DeflateStream class by using the specified stream and compression level.

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

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

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

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

Parameters

stream: Stream

The stream to which compressed data is written.

compressionLevel: CompressionLevel

One of the enumeration values that indicates whether to emphasize speed or compression efficiency when compressing data to the stream.

Exceptions

ArgumentNullException

stream is null.

ArgumentException

The stream does not support write operations such as compression. (The CanWrite property on the stream object is false.)

Remarks

You use this constructor when you want to specify whether compression efficiency or speed is more important for an instance of the DeflateStream class.

This constructor overload uses the compression mode Compress. To set the compression mode to another value, use the DeflateStream(Stream, CompressionMode) or DeflateStream(Stream, CompressionMode, Boolean) overload.

Examples

The following example shows how to set the compression level when creating a DeflateStream object and how to leave the stream open.

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

public static class FileCompressionLevelExample
{
    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.dfl";

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

        /*
         Output:
            The original file 'original.txt' is 445 bytes.
            The compressed file 'compressed.dfl' is 259 bytes.
         */
    }

    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 DeflateStream(compressedFileStream, CompressionLevel.Fastest);
        originalFileStream.CopyTo(compressor);
    }

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

        Console.WriteLine($"The original file '{OriginalFileName}' is {originalSize} bytes.");
        Console.WriteLine($"The compressed file '{CompressedFileName}' is {compressedSize} bytes.");
    }

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

Imports System.IO
Imports System.IO.Compression

Module FileCompressionLevelExample
    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.dfl"

    Sub Main()
        CreateFileToCompress()
        CompressFile()
        PrintResults()
        DeleteFiles()

        'Output:
        '   The original file 'original.txt' weighs 445 bytes.
        '   The compressed file 'compressed.dfl' weighs 259 bytes.
    End Sub

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

    Private Sub CompressFile()
        Using originalFileStream As FileStream = File.Open(OriginalFileName, FileMode.Open)
            Using compressedFileStream As FileStream = File.Create(CompressedFileName)
                Using compressor = New DeflateStream(compressedFileStream, CompressionLevel.Fastest)
                    originalFileStream.CopyTo(compressor)
                End Using
            End Using
        End Using
    End Sub

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

        Console.WriteLine($"The original file '{OriginalFileName}' weighs {originalSize} bytes.")
        Console.WriteLine($"The compressed file '{CompressedFileName}' weighs {compressedSize} bytes.")
    End Sub

    Private Sub DeleteFiles()
        File.Delete(OriginalFileName)
        File.Delete(CompressedFileName)
    End Sub
End Module

Applies to

DeflateStream(Stream, CompressionMode)

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Initializes a new instance of the DeflateStream class by using the specified stream and compression mode.

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

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

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

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

Parameters

stream: Stream

The stream to which compressed data is written or from which data to decompress is read.

mode: CompressionMode

One of the enumeration values that indicates whether to compress data to the stream or decompress data from the stream.

Exceptions

ArgumentNullException

stream is null.

ArgumentException

mode is not a valid CompressionMode value.

-or-

CompressionMode is Compress and CanWrite is false.

-or-

CompressionMode is Decompress and CanRead is false.

Remarks

By default, DeflateStream owns the underlying stream, so closing the stream also closes the underlying stream. Note that the state of the underlying stream can affect the usability of the stream. Also, no explicit checks are performed, so no additional exceptions are thrown when the new instance is created.

If an instance of the DeflateStream class is created with the mode parameter equal to Compress, header information is inserted immediately. If no further action occurs, the stream appears as a valid, empty, compressed file.

Using the DeflateStream class to compress a file larger than 4 GB raises an exception.

By default, the compression level is set to Optimal when the compression mode is Compress.

Examples

The following example shows how to use the DeflateStream class to compress and decompress a file.

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

public static 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.dfl";
    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.dfl' is 265 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 DeflateStream(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 DeflateStream(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);
    }
}

Imports System.IO
Imports System.IO.Compression

Module 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.dfl"
    Private Const DecompressedFileName As String = "decompressed.txt"

    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.dfl' weighs 265 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 Sub CreateFileToCompress()
        File.WriteAllText(OriginalFileName, Message)
    End Sub

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

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

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

Applies to

DeflateStream(Stream, CompressionLevel, Boolean)

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Initializes a new instance of the DeflateStream class by using the specified stream and compression level, and optionally leaves the stream open.

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

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

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

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

Parameters

stream: Stream

The stream to which compressed data is written.

compressionLevel: CompressionLevel

One of the enumeration values that indicates whether to emphasize speed or compression efficiency when compressing data to the stream.

leaveOpen: Boolean

true to leave the stream object open after disposing the DeflateStream object; otherwise, false.

Exceptions

ArgumentNullException

stream is null.

ArgumentException

The stream does not support write operations such as compression. (The CanWrite property on the stream object is false.)

Remarks

You use this constructor when you want to specify whether compression efficiency or speed is more important for an instance of the DeflateStream class, and whether to leave the stream object open after disposing the DeflateStream object.

Examples

The following example shows how to set the compression level when creating a DeflateStream object and how to leave the stream open.

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

public static class FileCompressionLevelExample
{
    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.dfl";

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

        /*
         Output:
            The original file 'original.txt' is 445 bytes.
            The compressed file 'compressed.dfl' is 259 bytes.
         */
    }

    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 DeflateStream(compressedFileStream, CompressionLevel.Fastest);
        originalFileStream.CopyTo(compressor);
    }

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

        Console.WriteLine($"The original file '{OriginalFileName}' is {originalSize} bytes.");
        Console.WriteLine($"The compressed file '{CompressedFileName}' is {compressedSize} bytes.");
    }

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

Imports System.IO
Imports System.IO.Compression

Module FileCompressionLevelExample
    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.dfl"

    Sub Main()
        CreateFileToCompress()
        CompressFile()
        PrintResults()
        DeleteFiles()

        'Output:
        '   The original file 'original.txt' weighs 445 bytes.
        '   The compressed file 'compressed.dfl' weighs 259 bytes.
    End Sub

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

    Private Sub CompressFile()
        Using originalFileStream As FileStream = File.Open(OriginalFileName, FileMode.Open)
            Using compressedFileStream As FileStream = File.Create(CompressedFileName)
                Using compressor = New DeflateStream(compressedFileStream, CompressionLevel.Fastest)
                    originalFileStream.CopyTo(compressor)
                End Using
            End Using
        End Using
    End Sub

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

        Console.WriteLine($"The original file '{OriginalFileName}' weighs {originalSize} bytes.")
        Console.WriteLine($"The compressed file '{CompressedFileName}' weighs {compressedSize} bytes.")
    End Sub

    Private Sub DeleteFiles()
        File.Delete(OriginalFileName)
        File.Delete(CompressedFileName)
    End Sub
End Module

Applies to

DeflateStream(Stream, CompressionMode, Boolean)

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Source:: DeflateStream.cs

Initializes a new instance of the DeflateStream class by using the specified stream and compression mode, and optionally leaves the stream open.

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

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

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

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

Parameters

stream: Stream

The stream to which compressed data is written or from which data to decompress is read.

mode: CompressionMode

One of the enumeration values that indicates whether to compress data to the stream or decompress data from the stream.

leaveOpen: Boolean

true to leave the stream open after disposing the DeflateStream object; otherwise, false.

Exceptions

ArgumentNullException

stream is null.

ArgumentException

mode is not a valid CompressionMode value.

-or-

CompressionMode is Compress and CanWrite is false.

-or-

CompressionMode is Decompress and CanRead is false.

Remarks

Using the DeflateStream class to compress a file larger than 4 GB raises an exception.

By default, the compression level is set to Optimal when the compression mode is Compress.

Examples

The following example shows how to use the DeflateStream class to compress and decompress a file.

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

public static 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.dfl";
    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.dfl' is 265 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 DeflateStream(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 DeflateStream(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);
    }
}

Imports System.IO
Imports System.IO.Compression

Module 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.dfl"
    Private Const DecompressedFileName As String = "decompressed.txt"

    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.dfl' weighs 265 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 Sub CreateFileToCompress()
        File.WriteAllText(OriginalFileName, Message)
    End Sub

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

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

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

Applies to

DeflateStream(Stream, ZLibCompressionOptions, Boolean)

Initializes a new instance of the DeflateStream class by using the specified stream, compression options, and optionally leaves the stream open.

public DeflateStream (System.IO.Stream stream, System.IO.Compression.ZLibCompressionOptions compressionOptions, bool leaveOpen = false);

new System.IO.Compression.DeflateStream : System.IO.Stream * System.IO.Compression.ZLibCompressionOptions * bool -> System.IO.Compression.DeflateStream

Public Sub New (stream As Stream, compressionOptions As ZLibCompressionOptions, Optional leaveOpen As Boolean = false)

Parameters

stream: Stream

The stream to which compressed data is written.

compressionOptions: ZLibCompressionOptions

The options for fine tuning the compression stream.

leaveOpen: Boolean

true to leave the stream object open after disposing the DeflateStream object; otherwise, false

Exceptions

ArgumentNullException

stream or compressionOptions is null.

Applies to

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DeflateStream Constructors

Definition

Overloads

Remarks

DeflateStream(Stream, CompressionLevel)

Parameters

Exceptions

Remarks

Examples

Applies to

DeflateStream(Stream, CompressionMode)

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Exceptions

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Examples

Applies to

DeflateStream(Stream, CompressionLevel, Boolean)

Parameters

Exceptions

Remarks

Examples

Applies to

DeflateStream(Stream, CompressionMode, Boolean)

Parameters

Exceptions

Remarks

Examples

Applies to

DeflateStream(Stream, ZLibCompressionOptions, Boolean)

Parameters

Exceptions

Applies to

Additional resources