wp8.1 页面返回 页面导航

public The_second()

public second()
{
    this.InitializeComponent();
    Frame frame = Window.Current.Content as Frame;
    frame.Navigating += Frame_Navigating;//请求新的页面导航是发生
}
private void Frame_Navigating(objectsender,NavigatingCancelEventArgs e)
{
    if (xxx参数)//参数..
   {
     e.Cancel = true;//是否取消
   }
}