wp8.1 頁面傳回 頁面導航

public The_second()      

public second()
{
    this.InitializeComponent();
    Frame frame = Window.Current.Content as Frame;
    frame.Navigating += Frame_Navigating;//請求新的頁面導航是發生
}
private void Frame_Navigating(objectsender,NavigatingCancelEventArgs e)
{
    if (xxx參數)//參數..
   { 
     e.Cancel = true;//是否取消
   }
}