/// <summary>
 /// 删除轮播窗体
 /// </summary>
 /// <param name="playWindow"></param>
 public void Del(PlayWindow playWindow)
 {
     if (playList.Contains(playWindow))
     {
         playWindow.Exit -= Play_Exit;
         playList.Remove(playWindow);
     }
 }
 /// <summary>
 /// 添加自动轮播窗体
 /// </summary>
 /// <param name="playWindow"></param>
 public void Add(PlayWindow playWindow)
 {
     if (!playList.Contains(playWindow) && playWindow.DelayTime > 0)
     {
         playList.Add(playWindow);
         playWindow.Playing = true;
         playWindow.Exit   += new PlayWindow.ExitHandle(Play_Exit);
     }
 }