1.Image配合Canvas,可以修改層級。
2.CanvasGroup不能獨立接收UI事件孵构,需要Image和它的RaycastTarget打開屁商。然后CanvasGroup需要BlocksRaycast打開。
3.子Canvas會阻礙UI事件
Unity UI Events not working for Canvas objects - Questions & Answers - Unity Discussions
4.transform.SetSiblingIndex
How do I change the sorting layer of a UI image when it is being dragged? - Questions & Answers - Unity Discussions
這個是排序卡牌用的關鍵所在