Xceed .NET Libraries Documentation
Compress(Byte[],CompressionMethod,CompressionLevel) Method


Xceed.Compression.Formats Assembly > Xceed.Compression.Formats Namespace > ZLibCompressedStream Class > Compress Method : Compress(Byte[],CompressionMethod,CompressionLevel) Method
The array of bytes to compress.
A Xceed.Compression.CompressionMethod value representing the compression method to use.
A Xceed.Compression.CompressionLevel value representing the compression level to use.
Compresses an array of bytes using the ZLib compression format with specified compression method and level.
Syntax
'Declaration
 
Public Overloads Shared Function Compress( _
   ByVal buffer() As Byte, _
   ByVal method As CompressionMethod, _
   ByVal level As CompressionLevel _
) As Byte()
'Usage
 
Dim buffer() As Byte
Dim method As CompressionMethod
Dim level As CompressionLevel
Dim value() As Byte
 
value = ZLibCompressedStream.Compress(buffer, method, level)
public static byte[] Compress( 
   byte[] buffer,
   CompressionMethod method,
   CompressionLevel level
)

Parameters

buffer
The array of bytes to compress.
method
A Xceed.Compression.CompressionMethod value representing the compression method to use.
level
A Xceed.Compression.CompressionLevel value representing the compression level to use.

Return Value

An array of bytes containing the compressed data.
Remarks

If the data to compress is not a byte array, it will need to be converted into a byte array before it can be compressed. This can be done, in the case of a string, using the System.Text.Encoding.GetBytes(System.Char[]) method of the System.Text.Encoding class.

The compression level only applies to the Deflated and Deflated64 compression methods.  It does not apply to the BZip2, BWT, or PPMd compression methods.

The PPMd algorithm uses a custom memory management system called SubAllocator. In a zip file, the memory size the SubAllocator uses is defined in the WinZip PPMd header for the compressed file and this header's value is used when decompressing the data. In general, WinZip uses 64Mb. Since the algorithm used was not optimized from the original PPMd version I revision 1, the SubAllocator initially requires the total amount of memory specified in the PPMd compressor. This means you must have at least 64 free Mb of RAM when using this compression method.

Requirements

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

See Also

Reference

ZLibCompressedStream Class
ZLibCompressedStream Members
Overload List