Zipping items in memory

This topic demonstrates how to add items in memory to a zip file using both the MemoryFile class and the OpenWrite method of the ZippedFile class.

Basic steps

To copy an item located in memory to a zip file using the MemoryFile class, the following steps must be performed:

Retrieve a reference to a file located in memory using the MemoryFile class. With Xceed Zip for .NET, a file is a file; it does not matter if it is located within a zip file, on disk or in memory.
If the file does not exist, create it.
Retrieve a reference to a new or existing zip file using the ZipArchive class.
Call the CopyTo method to copy the entire contents of the folder to the zip file.

To write a data directly in a zip file, the following steps must be performed:

Retrieve a reference to a new or existing zip file using the ZipArchive class.
Retrieve a reference to a new or existing file inside the zip file using the ZippedFile class.
Convert the data to write to the file within the zip file to a byte array.
Open a stream to the ZippedFile object using its OpenWrite method.
Write the data to the ZippedFile object.

Demonstration

This example demonstrates how to copy a file located in memory to a zip file.

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 file As New MemoryFile("RAM_DRIVE", "file.txt")` `If Not file.Exists Then file.Create() End If` `Dim zip As New ZipArchive(New DiskFile("d:\dump\test.zip") ) file.CopyTo(zip, True)`

Imports Xceed.Zip Imports Xceed.FileSystem

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

Dim file As New MemoryFile("RAM_DRIVE", "file.txt")

If Not file.Exists Then file.Create() End If

Dim zip As New ZipArchive(New DiskFile("d:\dump\test.zip") ) file.CopyTo(zip, True)

C# Copy Code

C#	Copy Code
`using Xceed.Zip; using Xceed.FileSystem;` `// Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework. MemoryFile file = new MemoryFile( "RAM_DRIVE", "file.txt" );` `if( !file.Exists ) file.Create();` `ZipArchive zip = new ZipArchive( new DiskFile( @"d:\dump\test.zip" ) ); file.CopyTo( zip, true );`

using Xceed.Zip; using Xceed.FileSystem;

// Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework. MemoryFile file = new MemoryFile( "RAM_DRIVE", "file.txt" );

if( !file.Exists ) file.Create();

ZipArchive zip = new ZipArchive( new DiskFile( @"d:\dump\test.zip" ) ); file.CopyTo( zip, true );

This next example demonstrates how to write data directly in a zip file.

VB.NET Copy Code

VB.NET	Copy Code
Imports Xceed.Zip Imports Xceed.FileSystem Imports System.IO ' Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework. Dim zipFile As New ZipArchive(New DiskFile("d:\dump\test.zip")) Dim file As ZippedFile = CType(zipFile.GetFile("file.txt"), ZippedFile) If Not file.Exists Then file.Create() End If Dim data As String = "This is the data which will be added to the zip file" ' Convert the data to a byte array. Dim byteData() As Byte = System.Text.Encoding.Default.GetBytes(data) ' Write the information to the ZippedFile object Dim stream As Stream = file.OpenWrite(True) stream.Write(byteData, 0, byteData.Length) stream.Close()

Imports Xceed.Zip
Imports Xceed.FileSystem
Imports System.IO

' Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework.
Dim zipFile As New ZipArchive(New DiskFile("d:\dump\test.zip"))
Dim file As ZippedFile = CType(zipFile.GetFile("file.txt"), ZippedFile)

If Not file.Exists Then
   file.Create()
End If

Dim data As String = "This is the data which will be added to the zip file"

' Convert the data to a byte array.
Dim byteData() As Byte = System.Text.Encoding.Default.GetBytes(data)

' Write the information to the ZippedFile object
Dim stream As Stream = file.OpenWrite(True)

stream.Write(byteData, 0, byteData.Length)
stream.Close()

C# Copy Code

C#	Copy Code
using Xceed.Zip; using Xceed.FileSystem; using System.IO; // If your trial period has expired, you must purchase a registered license key, // uncomment the next line of code, and insert your registered license key. // For more information, jump to the How the 45-day trial works and the // How to license the component topics. //Xceed.Zip.Licenser.LicenseKey = "ZINXX-XXXXX-XXXXX-XXXX"; // Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework. ZipArchive zipFile = new ZipArchive( new DiskFile( @"d:\dump\test.zip" ) ); ZippedFile file = ( ZippedFile )zipFile.GetFile( "file.txt" ); if( !file.Exists ) file.Create(); string data = "This is the data which will be added to the zip file"; // Convert the data to a byte array. byte[] byteData = System.Text.Encoding.Default.GetBytes( data ); // Write the information to the ZippedFile object using( Stream stream = file.OpenWrite( true ) ) { stream.Write( byteData, 0, byteData.Length ); }

using Xceed.Zip;
using Xceed.FileSystem;
using System.IO;

// If your trial period has expired, you must purchase a registered license key,
// uncomment the next line of code, and insert your registered license key.
// For more information, jump to the How the 45-day trial works and the
// How to license the component topics.
//Xceed.Zip.Licenser.LicenseKey = "ZINXX-XXXXX-XXXXX-XXXX";
// Note: Pathnames must be modified for code snippets to work under the .NET Compact Framework.

ZipArchive zipFile = new ZipArchive( new DiskFile( @"d:\dump\test.zip" ) );

ZippedFile file = ( ZippedFile )zipFile.GetFile( "file.txt" );

if( !file.Exists )
    file.Create();
  
string data = "This is the data which will be added to the zip file";

// Convert the data to a byte array.
byte[] byteData = System.Text.Encoding.Default.GetBytes( data );

// Write the information to the ZippedFile object
using( Stream stream = file.OpenWrite( true ) )
{
    stream.Write( byteData, 0, byteData.Length );
}

Things you should consider

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

Do you want to copy a folder rather than a file? Create a MemoryFolder class rather than a MemoryFile class.
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 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 only want to copy the contents of folder? Use the CopyFilesTo method.
Do you want to move items rather than copy them? Use the MoveTo and MoveFilesTo methods.
Do you want to change the location of the temporary folder. Set the ZipArchive's TempFolder or DefaultTempFolder property.
Do you only want to do basic zip file operations? Use the QuickZip class.
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.