ExtractAll

objZipFile = ZipFile.Read(sourceFilePath, objReadOptions);

if (!string.IsNullOrEmpty(password))
{
    objZipFile.Password = password;
}
                                
objZipFile.ExtractAll(destinationFilePath, ExtractExistingFileAction.InvokeExtractProgressEvent);

The event handler ExtractProgress doesnt get called at all although all files are extracted successfully. 