/// <summary>
 /// 右移
 /// </summary>
 /// <param name="index"></param>
 public void MoveRight(int index)
 {
     if (index < VideoItems.Count - 1)
     {
         VideoItems.Move(index, index + 1);
     }
 }
 /// <summary>
 /// 左移
 /// </summary>
 /// <param name="index"></param>
 public void MoveLeft(int index)
 {
     if (index > 0)
     {
         VideoItems.Move(index, index - 1);
     }
 }