public void OnPointerDown(PointerEventData eventData)
    {
        Debug.Log("点击了一下");
        ItemUI currentItem = transform.GetChild(0).GetComponent<ItemUI>();
        if (transform.childCount > 0)
        {
            if (InventoryManager.Instance.IsPickedItem == true)
            {
                Debug.Log("点击后是否选择了物品:" + InventoryManager.Instance.IsPickedItem);
            }

            if (InventoryManager.Instance.IsPickedItem == false)
            {
                Debug.Log("点击前是否选择了物品:" + InventoryManager.Instance.IsPickedItem);
                if (Input.GetKey(KeyCode.LeftControl))
                {
                    Debug.Log("鼠标上没有东西，按下了ctr");
                    int amountPicked = (currentItem.Amount + 1) / 2;
                    //Debug.Log(amountPicked);
                    InventoryManager.Instance.PickUpItem(currentItem.Item, amountPicked);
                    int amountRemained = currentItem.Amount - amountPicked;
                    if (amountRemained <= 0)
                    {
                        Destroy(currentItem.gameObject);
                    }
                    else
                    {
                        currentItem.SetAmount(amountRemained);
                    }
                }
                else
                {
                    Debug.Log("鼠标上没有东西，没有按下ctr");
                    InventoryManager.Instance.PickUpItem(currentItem.Item, currentItem.Amount);
                    Destroy(currentItem.gameObject);
                }

            }
            else
            {
                Debug.Log("为什么不执行这一段");
                Debug.Log(InventoryManager.Instance.IsPickedItem);
                if (currentItem.Item.ID == InventoryManager.Instance.PickedItem.Item.ID)
                {
                    if (Input.GetKey(KeyCode.LeftControl))
                    {
                        Debug.Log("相同的东西，按下了ctr");
                        if (currentItem.Item.Capacity > currentItem.Amount)//当前物品槽还有容量
                        {
                            currentItem.AddAmount();
                            //InventoryManager.Instance.RemoveOneItem();
                        }
                        else
                        {
                            return;
                        }
                    }
                }
            }
        }
    }

老师我上面这段代码，第一次检测鼠标按下的时候可以检测到，为什么检测不到第二次的鼠标按下呢，是不是UI遮挡的问题(吧物品的Raycasy Target勾掉也没有用)