public bool checkUI() {

　　PointerEventData data = new PointerEventData(eventSystem);

　　data.pressPosition = Input.mousePosition;

　　data.position= Input.mousePosition;

　　List<RaycastResult>list = new List<RaycastResult>();

　　RaycastInCanvas.Raycast(data,list);

 　   return list.Count > 0;

}