wpf实现框架frame中旧页面跳转新页面

Frame pageFrame = null;
  DependencyObject currParent = VisualTreeHelper.GetParent(this);
  while (currParent != null && pageFrame == null)
  {
 pageFrame = currParent as Frame;
 currParent = VisualTreeHelper.GetParent(currParent);
  }
  // Change the page of the frame.
  if (pageFrame != null)
  {
 pageFrame.Source = new Uri("WindowPages/LawCase/LawCasePanel.xaml", UriKind.Relative);
}