Easily zip / unzip files using Windows Shell32

Introduction

If you want to zip / unzip files without using third party libraries, and you want a method that can be used easily and works fine, you can use the Windows Shell32. I've written the code in VB 2010 using .NET Framework 2.0, but it's simple and can be easily converted to any other language like C#.

Using the Code

As I mentioned above, I'm going to use Visual Basic 2010 with .NET Framework 2.0.

1. Create a new project.
2. From the main menu, select Project -> Add Reference.
3. Select the COM tab and search for Microsoft Shell Controls and Automation.

How It Works

We will use the CopyHere command. We need to create an empty zip file, then we will use Shell32 to copy the files that we want to compress into the output Zip file. Or use it to unzip the files we have compressed previously to an output folder.

Imports Shell32
 
Public Class Form1
 
    Sub Zip()
        '1) Lets create an empty Zip File .
        'The following data represents an empty zip file .

        Dim startBuffer() As Byte = {80, 75, 5, 6, 0, 0, 0, 0, 0, 0, 0, _
                                     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} 
        ' Data for an empty zip file .
        FileIO.FileSystem.WriteAllBytes("d:\empty.zip", startBuffer, False)
 
        'We have successfully made the empty zip file .

        '2) Use the Shell32 to zip your files .
        ' Declare new shell class
        Dim sc As New Shell32.Shell()
        'Declare the folder which contains the files you want to zip .
        Dim input As Shell32.Folder = sc.NameSpace("D:\neededFiles")
        'Declare  your created empty zip file as folder  .
        Dim output As Shell32.Folder = sc.NameSpace("D:\empty.zip")
        'Copy the files into the empty zip file using the CopyHere command .
        output.CopyHere(input.Items, 4)
 
    End Sub
 
    Sub UnZip()
        Dim sc As New Shell32.Shell()
        ''UPDATE !!
        'Create directory in which you will unzip your files .
        IO.Directory.CreateDirectory("D:\extractedFiles") 
        'Declare the folder where the files will be extracted
        Dim output As Shell32.Folder = sc.NameSpace("D:\extractedFiles")
        'Declare your input zip file as folder  .
        Dim input As Shell32.Folder = sc.NameSpace("d:\myzip.zip")
        'Extract the files from the zip file using the CopyHere command .
        output.CopyHere(input.Items, 4)
 
    End Sub
 
End Class

In the CopyHere command, I have used option = 4. To use other options, please refer to this page:
http://msdn.microsoft.com/en-us/library/windows/desktop/bb787866(v=vs.85).aspx.

I hope I have provided something useful.