捕捉Silverlight程序全屏显示时候按ESC退出全屏显示

App.Current.Host.Content.FullScreenChanged+= new xxxxx

例子：

App.Current.Host.Content.FullScreenChanged += FullScreenChanged;

 

 private void FullScreenChanged(object sender, EventArgs handler)
        {
            if (Application.Current.Host.Content.IsFullScreen)
            {
                TextBlock tb = LayoutRoot.FindName("txt_fullscreen") as TextBlock;
                tb.Text = "退出全屏";
            }
            else
            {
                TextBlock tb = LayoutRoot.FindName("txt_fullscreen") as TextBlock;
                tb.Text = "全屏";
            }
        }