Unity用坐标来判断是否点击在UI上，并调用

        if (Input.GetMouseButtonDown(1))
        {
            //EventSystem.current就是场景中的EventSystem
            PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
            eventDataCurrentPosition.position = new Vector2(Input.mousePosition.x, Input.mousePosition.y);

            List results = new List();
            EventSystem.current.RaycastAll(eventDataCurrentPosition, results);

            if (results.Count > 0)
            {
                results[0].gameObject.GetComponent().onClick.Invoke();
            }
        }

        if (Input.GetMouseButtonDown(0) || (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began))
        {
#if IPHONE || ANDROID
			if (EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
#else
            if (EventSystem.current.IsPointerOverGameObject())
#endif
                Debug.Log("当前触摸在UI上" + EventSystem.current.currentSelectedGameObject.name);
            else
                Debug.Log("当前没有触摸在UI上");
        }