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GZipStream Constructor (Stream, CompressionMode)

Updated: January 2012

Initializes a new instance of the GZipStream class using the specified stream and CompressionMode value.

Namespace:  System.IO.Compression
Assembly:  System (in System.dll)

	Stream^ stream, 
	CompressionMode mode


Type: System.IO::Stream
The stream to compress or decompress.
Type: System.IO.Compression::CompressionMode
One of the CompressionMode values that indicates the action to take.


stream is nullptr.


mode is not a valid CompressionMode enumeration value.


CompressionMode is Compress and CanWrite is false.


CompressionMode is Decompress and CanRead is false.

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.

The GZipStream class might not be able to decompress data that results in over 8 GB of uncompressed data.

The following example initializes a new instance of the GZipStream class with mode set to Compress. This example is part of a larger example provided for the GZipStream class.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.




January 2012

Added information about decompression size limit.

Content bug fix.

March 2011

Corrected exceptions.

Information enhancement.