SEHException: 外部组件发生异常。
StackTrace:
   在 System.Windows.Input.InputElement.GetContainingUIElement(DependencyObject o, Boolean onlyTraverse2D)
   在 MS.Internal.UIElementHelper.GetUIParent(DependencyObject child, Boolean continuePastVisualTree)
   在 System.Windows.UIElement.BuildRouteHelper(DependencyObject e, EventRoute route, RoutedEventArgs args)
   在 System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   在 System.Windows.Input.RoutedCommand.CanExecuteImpl(Object parameter, IInputElement target, Boolean trusted, Boolean& continueRouting)
   在 MS.Internal.Commands.CommandHelpers.CanExecuteCommandSource(ICommandSource commandSource)
   在 System.Windows.Controls.Primitives.ButtonBase.UpdateCanExecute()
   在 System.Windows.WeakEventManager.ListenerList.DeliverEvent(Listener& listener, Object sender, EventArgs args, Type managerType)
   在 System.Windows.WeakEventManager.ListenerList.DeliverEvent(Object sender, EventArgs args, Type managerType)
   在 System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
   在 System.Windows.Input.CommandManager.RaiseRequerySuggested(Object obj)
   在 System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   在 System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)