Windows API to extract zip files? - winapi

Question

In Windows Explorer you can extract a compressed folder (a zip file)
Is there an API or command line to extract a zip file using the same method programatically?

Answer 1

You can use this VBScript script:
'Adapted from http://www.robvanderwoude.com/vbstech_files_zip.html
strFile = "c:\filename.zip"
strDest = "c:\files"
Set objFSO = CreateObject("Scripting.FileSystemObject")
If Not objFSO.FolderExists(strDest) Then
objFSO.CreateFolder(strDest)
End If
UnZipFile strFile, strDest
Sub UnZipFile(strArchive, strDest)
Set objApp = CreateObject( "Shell.Application" )
Set objArchive = objApp.NameSpace(strArchive).Items()
Set objDest = objApp.NameSpace(strDest)
objDest.CopyHere objArchive
End Sub

Answer 2

Check Compress Zip files with
Windows Shell API and C#
You could use SharpZipLib which
is free for a dot net project.

Answer 3

I tried the above function Sub UnZipFile(...) under Excel 2010 and it was not working: Run-time error '91' (Object variable or With block not set) in the line
Set objArchive = objApp.Namespace(strArchive).Items()
and the line
Set objDest = objApp.Namespace(strDest)
is silently also not working: After execution the objDest is still nothing!
Microsoft's .Namespace() accepts as parameter either an object, a string constant or a string variable. With string variables there are often suspicious problems, which are requiring an workaround:
Set objArchive = objApp.Namespace(**CStr(** strArchive **)**).Items()
Set objDest = objApp.Namespace(**CStr(** strDest **)**)
or an alternative workaround
Set objArchive = objApp.Namespace(**"" &** strArchive).Items()
Set objDest = objApp.Namespace(**"" &** strDest)
And the line objDest.CopyHere objArchive was also not working: The destination folder remained empty!
Here a version, which is working in Excel 2010 and most probably also in other environments:
Sub UnZipFile(strZipArchive As String, strDestFolder As String)
Dim objApp As Object
Dim vItem As Variant
Dim objDest As Object
Set objApp = CreateObject("Shell.Application")
Set objDest = objApp.Namespace(CStr(strDestFolder))
For Each vItem In objApp.Namespace(CStr(strZipArchive)).Items
objDest.CopyHere vItem
Next vItem
End Sub

Answer 4

For C# or VB users, you can check the answer from MSDN:
https://msdn.microsoft.com/en-us/library/ms404280(v=vs.100).aspx
For .net 4.x, here is the sample code from MSDN
using System;
using System.IO;
using System.IO.Compression;
namespace ConsoleApplication
{
class Program
{
static void Main(string[] args)
{
string startPath = #"c:\example\start";
string zipPath = #"c:\example\result.zip";
string extractPath = #"c:\example\extract";
ZipFile.CreateFromDirectory(startPath, zipPath);
ZipFile.ExtractToDirectory(zipPath, extractPath);
}
}
}