DeflateStream DeflateStream DeflateStream Constructors

Definition

Overloads

DeflateStream(Stream, CompressionLevel) DeflateStream(Stream, CompressionLevel) DeflateStream(Stream, CompressionLevel)

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

DeflateStream(Stream, CompressionMode) DeflateStream(Stream, CompressionMode) DeflateStream(Stream, CompressionMode)

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

DeflateStream(Stream, CompressionLevel, Boolean) DeflateStream(Stream, CompressionLevel, Boolean) 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) DeflateStream(Stream, CompressionMode, Boolean) 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.

Remarks

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

DeflateStream(Stream, CompressionLevel) DeflateStream(Stream, CompressionLevel) DeflateStream(Stream, CompressionLevel)

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

Parameters

stream
Stream Stream Stream

The stream to compress.

compressionLevel
CompressionLevel CompressionLevel CompressionLevel

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

Exceptions

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

Examples

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

using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string directoryPath = @"c:\users\public\reports";
            DirectoryInfo directorySelected = new DirectoryInfo(directoryPath);

            foreach (FileInfo fileToCompress in directorySelected.EnumerateFiles())
            {
                Compress(fileToCompress);
            }
        }

        public static void Compress(FileInfo fileToCompress)
        {
            using (FileStream originalFileStream = fileToCompress.OpenRead())
            {
                if ((File.GetAttributes(fileToCompress.FullName) & FileAttributes.Hidden) != FileAttributes.Hidden & fileToCompress.Extension != ".cmp")
                {
                    using (FileStream compressedFileStream = File.Create(fileToCompress.FullName + ".cmp"))
                    {
                        using (DeflateStream compressionStream = new DeflateStream(compressedFileStream, CompressionLevel.Fastest))
                        {
                            originalFileStream.CopyTo(compressionStream);
                        }
                    }
                }
            }
        }
    }
}
Imports System.IO
Imports System.IO.Compression

Module Module1

    Sub Main()
        Dim directoryPath As String = "c:\users\public\reports"
        Dim directorySelected As DirectoryInfo = New DirectoryInfo(directoryPath)

        For Each fileToCompress As FileInfo In directorySelected.EnumerateFiles()
            Compress(fileToCompress)
        Next
    End Sub

    Public Sub Compress(fileToCompress As FileInfo)
        Using originalFileStream As FileStream = fileToCompress.OpenRead()
            If ((File.GetAttributes(fileToCompress.FullName) & FileAttributes.Hidden) <> FileAttributes.Hidden And fileToCompress.Extension <> ".cmp") Then
                Using compressedFileStream As FileStream = File.Create(fileToCompress.FullName + ".cmp")
                    Using compressionStream As DeflateStream = New DeflateStream(compressedFileStream, CompressionLevel.Fastest)
                        originalFileStream.CopyTo(compressionStream)
                    End Using
                End Using
            End If
        End Using
    End Sub

End Module

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.

DeflateStream(Stream, CompressionMode) DeflateStream(Stream, CompressionMode) DeflateStream(Stream, CompressionMode)

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

Parameters

stream
Stream Stream Stream

The stream to compress or decompress.

mode
CompressionMode CompressionMode CompressionMode

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

Exceptions

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 class Program
{
    static string directoryPath = @"c:\temp";
    public static void Main()
    {
        
        DirectoryInfo directorySelected = new DirectoryInfo(directoryPath);
           Compress(directorySelected);
        

        foreach (FileInfo fileToDecompress in directorySelected.GetFiles("*.cmp"))
        {
            Decompress(fileToDecompress);
        }
    }

    public static void Compress(DirectoryInfo directorySelected)
    {
        
     
        foreach (FileInfo file in directorySelected.GetFiles("*.xml"))
        using (FileStream originalFileStream = file.OpenRead())
        {
            if ((File.GetAttributes(file.FullName) & FileAttributes.Hidden)
                != FileAttributes.Hidden & file.Extension != ".cmp")
            {
                using (FileStream compressedFileStream = File.Create(file.FullName + ".cmp"))
                {
                    using (DeflateStream compressionStream = new DeflateStream(compressedFileStream, CompressionMode.Compress))
                    {
                        originalFileStream.CopyTo(compressionStream);
                    }
                }

                FileInfo info = new FileInfo(directoryPath + "\\" + file.Name + ".cmp");
                Console.WriteLine("Compressed {0} from {1} to {2} bytes.", file.Name, file.Length, info.Length);
            }
        }
    }

    public static void Decompress(FileInfo fileToDecompress)
    {
        using (FileStream originalFileStream = fileToDecompress.OpenRead())
        {
            string currentFileName = fileToDecompress.FullName;
            string newFileName = currentFileName.Remove(currentFileName.Length - fileToDecompress.Extension.Length);

            using (FileStream decompressedFileStream = File.Create(newFileName))
            {
                using (DeflateStream decompressionStream = new DeflateStream(originalFileStream, CompressionMode.Decompress))
                {
                    decompressionStream.CopyTo(decompressedFileStream);
                    Console.WriteLine("Decompressed: {0}", fileToDecompress.Name);
                }
            }
        }
    }
}
Imports System.IO
Imports System.IO.Compression

Public Class Program
    Shared directoryPath As String = "c:\temp"
    Public Shared Sub Main()

        Dim directorySelected As New DirectoryInfo(directoryPath)
        Compress(directorySelected)


        For Each fileToDecompress As FileInfo In directorySelected.GetFiles("*.cmp")
            Decompress(fileToDecompress)
        Next
    End Sub

    Public Shared Sub Compress(directorySelected As DirectoryInfo)

        For Each file__1 As FileInfo In directorySelected.GetFiles("*.xml")
            Using originalFileStream As FileStream = file__1.OpenRead()
                If (File.GetAttributes(file__1.FullName) And FileAttributes.Hidden) <> FileAttributes.Hidden And file__1.Extension <> ".cmp" Then
                    Using compressedFileStream As FileStream = File.Create(file__1.FullName & ".cmp")
                        Using compressionStream As Compression.DeflateStream = New DeflateStream(compressedFileStream, CompressionMode.Compress)
                            originalFileStream.CopyTo(compressionStream)
                        End Using
                    End Using

                    Dim info As New FileInfo(directoryPath & "\" & file__1.Name & ".cmp")
                    Console.WriteLine("Compressed {0} from {1} to {2} bytes.", file__1.Name, file__1.Length, info.Length)
                End If
            End Using
        Next
    End Sub

    Public Shared Sub Decompress(fileToDecompress As FileInfo)
        Using originalFileStream As FileStream = fileToDecompress.OpenRead()
            Dim currentFileName As String = fileToDecompress.FullName
            Dim newFileName As String = currentFileName.Remove(currentFileName.Length - fileToDecompress.Extension.Length)

            Using decompressedFileStream As FileStream = File.Create(newFileName)
                Using decompressionStream As New DeflateStream(originalFileStream, CompressionMode.Decompress)
                    decompressionStream.CopyTo(decompressedFileStream)
                    Console.WriteLine("Decompressed: {0}", fileToDecompress.Name)
                End Using
            End Using
        End Using
    End Sub
End Class

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.

DeflateStream(Stream, CompressionLevel, Boolean) DeflateStream(Stream, CompressionLevel, Boolean) 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.

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

Parameters

stream
Stream Stream Stream

The stream to compress.

compressionLevel
CompressionLevel CompressionLevel CompressionLevel

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

leaveOpen
Boolean Boolean Boolean

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

Exceptions

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

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.Collections.Generic;
using System.IO;
using System.IO.Compression;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string directoryPath = @"c:\users\public\reports";
            DirectoryInfo directorySelected = new DirectoryInfo(directoryPath);

            foreach (FileInfo fileToCompress in directorySelected.EnumerateFiles())
            {
                Compress(fileToCompress);
            }
        }

        public static void Compress(FileInfo fileToCompress)
        {
            using (FileStream originalFileStream = fileToCompress.OpenRead())
            {
                if ((File.GetAttributes(fileToCompress.FullName) & FileAttributes.Hidden) != FileAttributes.Hidden & fileToCompress.Extension != ".cmp")
                {
                    using (FileStream compressedFileStream = File.Create(fileToCompress.FullName + ".cmp"))
                    {
                        using (DeflateStream compressionStream = new DeflateStream(compressedFileStream, CompressionLevel.Fastest, true))
                        {
                            originalFileStream.CopyTo(compressionStream);
                        }
                        Console.WriteLine(string.Format("file compressed to {0} bytes", compressedFileStream.Length));
                    }
                }
            }
        }
    }
}
Imports System.IO
Imports System.IO.Compression

Module Module1

    Sub Main()
        Dim directoryPath As String = "c:\users\public\reports"
        Dim directorySelected As DirectoryInfo = New DirectoryInfo(directoryPath)

        For Each fileToCompress As FileInfo In directorySelected.EnumerateFiles()
            Compress(fileToCompress)
        Next
    End Sub

    Public Sub Compress(fileToCompress As FileInfo)
        Using originalFileStream As FileStream = fileToCompress.OpenRead()
            If ((File.GetAttributes(fileToCompress.FullName) & FileAttributes.Hidden) <> FileAttributes.Hidden And fileToCompress.Extension <> ".cmp") Then
                Using compressedFileStream As FileStream = File.Create(fileToCompress.FullName + ".cmp")
                    Using compressionStream As DeflateStream = New DeflateStream(compressedFileStream, CompressionLevel.Fastest, True)
                        originalFileStream.CopyTo(compressionStream)
                    End Using
                    Console.WriteLine(String.Format("file compressed to {0} bytes", compressedFileStream.Length))
                End Using
            End If
        End Using
    End Sub

End Module

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.

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.

DeflateStream(Stream, CompressionMode, Boolean) DeflateStream(Stream, CompressionMode, Boolean) 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.

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

Parameters

stream
Stream Stream Stream

The stream to compress or decompress.

mode
CompressionMode CompressionMode CompressionMode

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

leaveOpen
Boolean Boolean Boolean

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

Exceptions

Examples

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

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

public class Program
{
    static string directoryPath = @"c:\temp";
    public static void Main()
    {
        
        DirectoryInfo directorySelected = new DirectoryInfo(directoryPath);
           Compress(directorySelected);
        

        foreach (FileInfo fileToDecompress in directorySelected.GetFiles("*.cmp"))
        {
            Decompress(fileToDecompress);
        }
    }

    public static void Compress(DirectoryInfo directorySelected)
    {
        
     
        foreach (FileInfo file in directorySelected.GetFiles("*.xml"))
        using (FileStream originalFileStream = file.OpenRead())
        {
            if ((File.GetAttributes(file.FullName) & FileAttributes.Hidden)
                != FileAttributes.Hidden & file.Extension != ".cmp")
            {
                using (FileStream compressedFileStream = File.Create(file.FullName + ".cmp"))
                {
                    using (DeflateStream compressionStream = new DeflateStream(compressedFileStream, CompressionMode.Compress))
                    {
                        originalFileStream.CopyTo(compressionStream);
                    }
                }

                FileInfo info = new FileInfo(directoryPath + "\\" + file.Name + ".cmp");
                Console.WriteLine("Compressed {0} from {1} to {2} bytes.", file.Name, file.Length, info.Length);
            }
        }
    }

    public static void Decompress(FileInfo fileToDecompress)
    {
        using (FileStream originalFileStream = fileToDecompress.OpenRead())
        {
            string currentFileName = fileToDecompress.FullName;
            string newFileName = currentFileName.Remove(currentFileName.Length - fileToDecompress.Extension.Length);

            using (FileStream decompressedFileStream = File.Create(newFileName))
            {
                using (DeflateStream decompressionStream = new DeflateStream(originalFileStream, CompressionMode.Decompress))
                {
                    decompressionStream.CopyTo(decompressedFileStream);
                    Console.WriteLine("Decompressed: {0}", fileToDecompress.Name);
                }
            }
        }
    }
}
Imports System.IO
Imports System.IO.Compression

Public Class Program
    Shared directoryPath As String = "c:\temp"
    Public Shared Sub Main()

        Dim directorySelected As New DirectoryInfo(directoryPath)
        Compress(directorySelected)


        For Each fileToDecompress As FileInfo In directorySelected.GetFiles("*.cmp")
            Decompress(fileToDecompress)
        Next
    End Sub

    Public Shared Sub Compress(directorySelected As DirectoryInfo)

        For Each file__1 As FileInfo In directorySelected.GetFiles("*.xml")
            Using originalFileStream As FileStream = file__1.OpenRead()
                If (File.GetAttributes(file__1.FullName) And FileAttributes.Hidden) <> FileAttributes.Hidden And file__1.Extension <> ".cmp" Then
                    Using compressedFileStream As FileStream = File.Create(file__1.FullName & ".cmp")
                        Using compressionStream As Compression.DeflateStream = New DeflateStream(compressedFileStream, CompressionMode.Compress)
                            originalFileStream.CopyTo(compressionStream)
                        End Using
                    End Using

                    Dim info As New FileInfo(directoryPath & "\" & file__1.Name & ".cmp")
                    Console.WriteLine("Compressed {0} from {1} to {2} bytes.", file__1.Name, file__1.Length, info.Length)
                End If
            End Using
        Next
    End Sub

    Public Shared Sub Decompress(fileToDecompress As FileInfo)
        Using originalFileStream As FileStream = fileToDecompress.OpenRead()
            Dim currentFileName As String = fileToDecompress.FullName
            Dim newFileName As String = currentFileName.Remove(currentFileName.Length - fileToDecompress.Extension.Length)

            Using decompressedFileStream As FileStream = File.Create(newFileName)
                Using decompressionStream As New DeflateStream(originalFileStream, CompressionMode.Decompress)
                    decompressionStream.CopyTo(decompressedFileStream)
                    Console.WriteLine("Decompressed: {0}", fileToDecompress.Name)
                End Using
            End Using
        End Using
    End Sub
End Class

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.

Applies to