public MainWindow()
 {
     InitializeComponent();
     _spider = new Spider();
     _spider.ContentsSaved += new Spider.ContentsSavedHandler(Spider_ContentsSaved);
     _spider.DownloadFinish += new Spider.DownloadFinishHandler(Spider_DownloadFinish);
     this.Closed += new EventHandler(MainWindow_Closed);
     this.Loaded += new RoutedEventHandler(MainWindow_Loaded);
     btnStop.IsEnabled = false;
 }