GZipStream Constructors
Definition
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 GZipStream class.
Overloads
GZipStream(Stream, CompressionLevel) |
Initializes a new instance of the GZipStream class by using the specified stream and compression level. |
GZipStream(Stream, CompressionMode) |
Initializes a new instance of the GZipStream class by using the specified stream and compression mode. |
GZipStream(Stream, CompressionLevel, Boolean) |
Initializes a new instance of the GZipStream class by using the specified stream and compression level, and optionally leaves the stream open. |
GZipStream(Stream, CompressionMode, Boolean) |
Initializes a new instance of the GZipStream class by using the specified stream and compression mode, and optionally leaves the stream open. |
GZipStream(Stream, CompressionLevel)
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
Initializes a new instance of the GZipStream class by using the specified stream and compression level.
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)
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
stream
is null
.
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 GZipStream class.
This constructor overload uses the compression mode Compress. To set the compression mode to another value, use the GZipStream(Stream, CompressionMode) or GZipStream(Stream, CompressionMode, Boolean) overload.
Applies to
GZipStream(Stream, CompressionMode)
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
Initializes a new instance of the GZipStream class by using the specified stream and compression mode.
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)
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
stream
is null
.
mode
is not a valid CompressionMode enumeration value.
-or-
CompressionMode is Compress and CanWrite is false
.
-or-
CompressionMode is Decompress and CanRead is false
.
Examples
The following example shows how to set the compression mode when creating a GZipStream object.
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
Remarks
By default, GZipStream owns the underlying stream, so closing the stream
parameter 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 GZipStream class is created with the mode
parameter equal to Compress
and no further action occurs, the stream will appear as a valid, empty compressed file.
By default, the compression level is set to Optimal when the compression mode is Compress.
Applies to
GZipStream(Stream, CompressionLevel, Boolean)
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
Initializes a new instance of the GZipStream class by using the specified stream and compression level, and optionally leaves the stream open.
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)
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 GZipStream object; otherwise, false
.
Exceptions
stream
is null
.
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 GZipStream object and how to leave the stream open.
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
Remarks
You use this constructor when you want to specify whether compression efficiency or speed is more important for an instance of the GZipStream class, and whether to leave the stream object open after disposing the GZipStream object.
This constructor overload uses the compression mode Compress. To set the compression mode to another value, use the GZipStream(Stream, CompressionMode) or GZipStream(Stream, CompressionMode, Boolean) overload.
Applies to
GZipStream(Stream, CompressionMode, Boolean)
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
- Source:
- GZipStream.cs
Initializes a new instance of the GZipStream class by using the specified stream and compression mode, and optionally leaves the stream open.
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)
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 GZipStream object; otherwise, false
.
Exceptions
stream
is null
.
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, GZipStream owns the underlying stream, so closing the stream
parameter also closes the underlying stream. 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 GZipStream class is created with the mode
parameter equal to Compress
and no further action occurs, the stream will appear as a valid, empty compressed file.
By default, the compression level is set to Optimal when the compression mode is Compress.
Applies to
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