Introduction

This topic demonstrates how to create a zip file in memory.

Basic steps

To create a zip file in memory, the following steps must be performed:

Retrieve a reference to a folder whose files will be added to the zip file using either the DiskFolder, ZippedFolder, ZipArchive, MemoryFolder or IsolatedFolder classes. With Xceed Zip for .NET, a folder is a folder; it does not matter if it is located within a zip file, on disk or in memory.
Retrieve a reference to a new or existing zip file using the ZipArchive class. Because we want the zip file to reside in memory, we will use a MemoryFile in the constructor of the ZipArchive class.
Call the CopyFilesTo method to copy the entire contents of the folder to the zip file.

Demonstration

This example demonstrates how to copy the contents of a folder located on disk to a zip file located in memory.

VB.NET Copy Code

VB.NET	Copy Code
`Imports Xceed.Zip Imports Xceed.FileSystem` `' Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework.` `Dim folder As New DiskFolder("c:\windows\fonts") Dim memFile As New MemoryFile("RAM_File", "fonts.zip") Dim zip As New ZipArchive(memFile)` `folder.CopyFilesTo( zip, false, true )` `' Once the zip file has been created, if you want to convert it ' to a byte array, the following code can be used:` `Dim baZip() As Byte Dim memStream As New MemoryStream()` `Dim s As Stream = memFile.OpenRead()` `Dim buffer(1024) As Byte Dim bytesRead As Integer` `Do bytesRead = s.Read(buffer, 0, buffer.Length)` `If bytesRead > 0 Then memStream.Write(buffer, 0, bytesRead) End If Loop Until bytesRead = 0` `s.Close()` `' Get the byte array from the memory stream baZip = memStream.ToArray() memStream.Close()`

Imports Xceed.Zip Imports Xceed.FileSystem

' Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework.

Dim folder As New DiskFolder("c:\windows\fonts") Dim memFile As New MemoryFile("RAM_File", "fonts.zip") Dim zip As New ZipArchive(memFile)

folder.CopyFilesTo( zip, false, true )

' Once the zip file has been created, if you want to convert it ' to a byte array, the following code can be used:

Dim baZip() As Byte Dim memStream As New MemoryStream()

Dim s As Stream = memFile.OpenRead()

Dim buffer(1024) As Byte Dim bytesRead As Integer

Do bytesRead = s.Read(buffer, 0, buffer.Length)

If bytesRead > 0 Then memStream.Write(buffer, 0, bytesRead) End If Loop Until bytesRead = 0

s.Close()

' Get the byte array from the memory stream baZip = memStream.ToArray() memStream.Close()

C# Copy Code

C#	Copy Code
using Xceed.Zip; using Xceed.FileSystem; using System.IO; // Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework. DiskFolder folder = new DiskFolder( @"c:\windows\fonts" ); MemoryFile memFile = new MemoryFile( "RAM_File", "fonts.zip" ); ZipArchive zip = new ZipArchive( memFile ); folder.CopyFilesTo( zip, false, true ); // Once the zip file has been created, if you want to convert it // to a byte array, the following code can be used: byte[] baZip; using( MemoryStream memStream = new MemoryStream() ) { using( Stream s = memFile.OpenRead() ) { byte[] buffer = new byte[ 1024 ]; int bytesRead; while( ( bytesRead = s.Read( buffer, 0, buffer.Length ) ) > 0 ) { memStream.Write( buffer, 0, bytesRead ); } } // Get the byte array from the memory stream baZip = memStream.ToArray(); }

using Xceed.Zip;
using Xceed.FileSystem;
using System.IO;
 
// Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework.
 
DiskFolder folder = new DiskFolder( @"c:\windows\fonts" ); 
MemoryFile memFile = new MemoryFile( "RAM_File", "fonts.zip" ); 
ZipArchive zip = new ZipArchive( memFile );
 
folder.CopyFilesTo( zip, false, true );
 
// Once the zip file has been created, if you want to convert it
// to a byte array, the following code can be used:
 
byte[] baZip;
 
using( MemoryStream memStream = new MemoryStream() )
{
   using( Stream s = memFile.OpenRead() )
   {
      byte[] buffer = new byte[ 1024 ];
      int bytesRead;
 
      while( ( bytesRead = s.Read( buffer, 0, buffer.Length ) ) > 0 )
      {
         memStream.Write( buffer, 0, bytesRead );
      }
   } 
 
   // Get the byte array from the memory stream
   baZip = memStream.ToArray();
}

Things you should consider

The main questions you should ask yourself when copying items to a zip file are:

Do you want to filter (specify specific files and folders) the items that are to be added to the zip file? Use filters.
Do you want to display the status of the operation? See the Handling events topic.
Do you want to add items into a specific folder within the zip file? Create an instance of a ZippedFolder object rather than a ZipArchive object.
Do you want to change the location of the temporary folder. Set the ZipArchive's TempFolder or DefaultTempFolder property.
Do you only want to copy a specific file or folder? Use the CopyTo method.
Do you want to move items rather than copy them? Use the MoveTo and MoveFilesTo methods.
Do you want to modify the default extra headers that are stored to a zip file? Set the ZipArchive's DefaultExtraHeaders property.

All zip files will automatically be created in the Zip64 zip file format if the limitations of the regular Zip format are reached.

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