zlib.ZStream.Open

Method Signatures

 Shared Function Open(InputStream As Readable,   Encoding As Integer = zlib.Z_DETECT) As zlib.ZStream
 Shared Function Open(InputStream As FolderItem, Encoding As Integer = zlib.Z_DETECT) As zlib.ZStream

Parameters

Name	Type	Comment
InputStream	Readable, FolderItem	The file or stream to decompress from.
Encoding	Integer	Optional. The type of compression.

Return value

A new instance of ZStream.

Remarks

Opens a compressed file or readable stream for decompression. 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)