Try this :
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Core;
public class UnZipFileFolder
{
public string setPassword = "";
public void UnZip(string srcFileName, string dstFolderName)
{
using (ZipInputStream s = new ZipInputStream(File.OpenRead(@"" + srcFileName)))
{
if (setPassword.Trim() != "") s.Password = setPassword;
ZipEntry theEntry;
while ((theEntry = s.GetNextEntry()) != null)
{
string directoryName = Path.GetDirectoryName(dstFolderName);
string fileName = dstFolderName + "\\" + Path.GetFileName(theEntry.Name);
if (fileName != String.Empty)
{
using (FileStream streamWriter = File.Create(fileName))
{
int size = 2048;
byte[] data = new byte[2048];
while (true)
{
size = s.Read(data, 0, data.Length);
if (size > 0)
{
streamWriter.Write(data, 0, size);
}
else
{
break;
}
}
}
}
}
}
}
}