'Declaration
 
Public Overloads Shared Shadows Function Compress( _
   ByVal buffer() As Byte, _
   ByVal method As CompressionMethod, _
   ByVal level As CompressionLevel, _
   ByVal encryptionPassword As String _
) As Byte()

'Usage
 
Dim buffer() As Byte
Dim method As CompressionMethod
Dim level As CompressionLevel
Dim encryptionPassword As String
Dim value() As Byte
 
value = XceedCompressedStreamEx.Compress(buffer, method, level, encryptionPassword)

public new static byte[] Compress( 
   byte[] buffer,
   CompressionMethod method,
   CompressionLevel level,
   string encryptionPassword
)

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.

encryptionPassword

The encryption password to use.

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.

.NET: net5.0, net5.0-windows, net6.0, net6.0-macos, net6.0-windows, net7.0, net7.0-macos, net7.0-windows, net8.0, net8.0-browser, net8.0-macos, net8.0-windows, net9.0, net9.0-browser, net9.0-macos, net9.0-windows, net10.0, net10.0-browser, net10.0-macos, net10.0-windows.

.NET Standard: netstandard2.0, netstandard2.1

.NET Framework: net20, net35, net40, net403, net45, net451, net452, net46, net461, net462, net463, net47, net471, net472, net48, net481.

Reference

XceedCompressedStreamEx Class
XceedCompressedStreamEx Members
Overload List
System.Text.Encoding.GetBytes(System.Char[])
System.Text.Encoding