在这种情况下我如何使用进度条？voidClient_DownloadFileCompleted(objectsender,AsyncCompletedEventArgse){//System.Windows.MessageBox.Show("UpdateComplete!","Message",MessageBoxButton.OK,MessageBoxImage.Information);Uriuri=newUri(url);stringfilename=System.IO.Path.GetFileName(uri.AbsolutePath);ZipFile.ExtractToDir