zlib.ZStream.Create

Method Signatures

 Shared Function Create(OutputStream As Writeable,  CompressionLevel As Integer = zlib.Z_DEFAULT_COMPRESSION, Encoding As Integer = zlib.DEFLATE_ENCODING) As zlib.ZStream
 Shared Function Create(OutputStream As FolderItem, CompressionLevel As Integer = zlib.Z_DEFAULT_COMPRESSION, Overwrite As Boolean = False, Encoding As Integer = zlib.DEFLATE_ENCODING) As zlib.ZStream

Parameters

Name	Type	Comment
OutputStream	`Writeable`, `FolderItem`	Compressed output will be written to this object
CompressionLevel	Integer	Optional. The compression level for the stream. Valid levels are `1`(fast) to `9`(best)
Overwrite	Boolean	Optional. If `True`, the `OutputStream` FolderItem is overwritten if it exists.
Encoding	Integer	Optional. The type of compression.

Return value

A new instance of ZStream.

Remarks

Creates a new deflate stream for writing. Compressed data will be written to the OutputStream object. On error an exception will be raised.

Example

This example demonstrates how to use the ZStream.Open and ZStream.Create shared methods in concert with the built-in BinaryStream class to read and write a gzip-compressed text file on the user's desktop.

Dim outfile As FolderItem = SpecialFolder.Desktop.Child("hello.txt.gz")
Dim filestream As BinaryStream
Dim gzipstream As zlib.ZStream

' Create the file and then the compression stream
filestream = BinaryStream.Create(outfile)
gzipstream = zlib.ZStream.Create(filestream, zlib.Z_DEFAULT_COMPRESSION, zlib.GZIP_ENCODING)
For i As Integer = 0 To 9
  gzipstream.Write("This text will be compressed using gzip!")
Next
gzipstream.Close()
filestream.Close()

' Open the file and then the decompression stream
filestream = BinaryStream.Open(outfile)
gzipstream = zlib.ZStream.Open(filestream, zlib.GZIP_ENCODING)
Dim s As String
Do Until gzipstream.EOF
  s = gzipstream.Read(1024 * 64)
Loop
gzipstream.Close()
filestream.Close()

MsgBox(s)