Xceed Real-Time Zip for .NET Documentation
Compress(Byte[],Int32,Int32,CompressionMethod,CompressionLevel,String) Method


Xceed.Compression.Formats Assembly > Xceed.Compression.Formats Namespace > XceedCompressedStreamEx Class > Compress Method : Compress(Byte[],Int32,Int32,CompressionMethod,CompressionLevel,String) Method
The array of bytes to compress. A maximum of count bytes are taken from this array and compressed
The byte offset in buffer at which to begin taking the data to compress.
The maximum number of bytes to be taken from buffer.
A Xceed.Compression.CompressionMethod value representing the compression method to use.
A Xceed.Compression.CompressionLevel value representing the compression level to use.
The encryption password to use.
Compresses an array of bytes using the extended Xceed compression format specifying the amount of bytes to compress as well as compression method and level, and the encryption password. Use this method to compress data compatible with the ActiveX Xceed Zip Compression Library (XceedCompression object).
Syntax
'Declaration
 
Public Overloads Shared Shadows Function Compress( _
   ByVal buffer() As Byte, _
   ByVal offset As Integer, _
   ByVal count As Integer, _
   ByVal method As CompressionMethod, _
   ByVal level As CompressionLevel, _
   ByVal encryptionPassword As String _
) As Byte()
'Usage
 
Dim buffer() As Byte
Dim offset As Integer
Dim count As Integer
Dim method As CompressionMethod
Dim level As CompressionLevel
Dim encryptionPassword As String
Dim value() As Byte
 
value = XceedCompressedStreamEx.Compress(buffer, offset, count, method, level, encryptionPassword)
public new static byte[] Compress( 
   byte[] buffer,
   int offset,
   int count,
   CompressionMethod method,
   CompressionLevel level,
   string encryptionPassword
)

Parameters

buffer
The array of bytes to compress. A maximum of count bytes are taken from this array and compressed
offset
The byte offset in buffer at which to begin taking the data to compress.
count
The maximum number of bytes to be taken from buffer.
method
A Xceed.Compression.CompressionMethod value representing the compression method to use.
level
A Xceed.Compression.CompressionLevel value representing the compression level to use.
encryptionPassword
The encryption password to use.
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 Stored compression method is not supported. 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

XceedCompressedStreamEx Class
XceedCompressedStreamEx Members
Overload List