UGUI 点击穿透问题

unity上 用 做游戏欢迎界面上通用的ui，然后导到游戏里面直接用，但发现游戏里面是用ngui的，点击ugui 的ui 会穿透过去 ngui会响应，原本模型的点击处理也会响应

我用的 unity 版本 是 4.6.3的

本来是用   EventSystem.current.IsPointerOverGameObject()   来检测点击穿透的

在pc的unity编辑器上都可以检测到。可是打包到android 上 就无效，网上有的说以前的版本可以，不知道是不是之后的bug，还是有其他的接口

在网上搜到了这里，找到以下解决方法：

 1     /// <summary>
 2     /// Cast a ray to test if Input.mousePosition is over any UI object in EventSystem.current. This is a replacement
 3     /// for IsPointerOverGameObject() which does not work on Android in 4.6.0f3
 4     /// </summary>
 5     private static bool IsPointerOverUIObject()
 6     {
 7         if (EventSystem.current == null)
 8             return false;
 9
10         // Referencing this code for GraphicRaycaster https://gist.github.com/stramit/ead7ca1f432f3c0f181f
11         // the ray cast appears to require only eventData.position.
12         PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
13         eventDataCurrentPosition.position = new Vector2(Input.mousePosition.x, Input.mousePosition.y);
14
15         List<RaycastResult> results = new List<RaycastResult>();
16         EventSystem.current.RaycastAll(eventDataCurrentPosition, results);
17
18         return results.Count > 0;
19     }
20
21     /// <summary>
22     /// Cast a ray to test if screenPosition is over any UI object in canvas. This is a replacement
23     /// for IsPointerOverGameObject() which does not work on Android in 4.6.0f3
24     /// </summary>
25     private bool IsPointerOverUIObject(Canvas canvas, Vector2 screenPosition)
26     {
27         if (EventSystem.current == null)
28             return false;
29
30         // Referencing this code for GraphicRaycaster https://gist.github.com/stramit/ead7ca1f432f3c0f181f
31         // the ray cast appears to require only eventData.position.
32         PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
33         eventDataCurrentPosition.position = screenPosition;
34
35         GraphicRaycaster uiRaycaster = canvas.gameObject.GetComponent<GraphicRaycaster>();
36         List<RaycastResult> results = new List<RaycastResult>();
37         uiRaycaster.Raycast(eventDataCurrentPosition, results);
38         return results.Count > 0;
39     }