Xceed .NET Libraries Documentation
OpenWrite(FileSystemEvents,Object,Boolean,CompressionMethod,CompressionLevel,String) Method


Xceed.Zip Assembly > Xceed.Zip Namespace > ZippedFile Class > OpenWrite Method : OpenWrite(FileSystemEvents,Object,Boolean,CompressionMethod,CompressionLevel,String) Method
A Xceed.FileSystem.FileSystemEvents object that will be used to raise events. Cannot be a null reference (Nothing in Visual Basic).
Opaque data that will be passed back to the event handler when an event is raised.
true if existing data for the item should be replaced; false if existing data should be preserved, appending new data at the end.
The CompressionMethod that will be used to compress the file.
The CompressionLevel that will be used when compressing the file.
The password that will be used to encrypt the file.
Opens the file for writing providing an encryption password and specifying if existing data should be replaced. Events will be raised during the process.
Syntax
'Declaration
 
Public Overloads Function OpenWrite( _
   ByVal events As FileSystemEvents, _
   ByVal userData As Object, _
   ByVal overwrite As Boolean, _
   ByVal compressionMethod As CompressionMethod, _
   ByVal compressionLevel As CompressionLevel, _
   ByVal encryptionPassword As String _
) As Stream
'Usage
 
Dim instance As ZippedFile
Dim events As FileSystemEvents
Dim userData As Object
Dim overwrite As Boolean
Dim compressionMethod As CompressionMethod
Dim compressionLevel As CompressionLevel
Dim encryptionPassword As String
Dim value As Stream
 
value = instance.OpenWrite(events, userData, overwrite, compressionMethod, compressionLevel, encryptionPassword)

Parameters

events
A Xceed.FileSystem.FileSystemEvents object that will be used to raise events. Cannot be a null reference (Nothing in Visual Basic).
userData
Opaque data that will be passed back to the event handler when an event is raised.
overwrite
true if existing data for the item should be replaced; false if existing data should be preserved, appending new data at the end.
compressionMethod
The CompressionMethod that will be used to compress the file.
compressionLevel
The CompressionLevel that will be used when compressing the file.
encryptionPassword
The password that will be used to encrypt the file.

Return Value

A System.IO.Stream object that can be used to write data to the file.
Remarks

The returned stream is guaranteed to be writable, but may or may not be seekable.

The file will be opened with System.IO.FileShare.None shared access.

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

ZippedFile Class
ZippedFile Members
Overload List