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：
/// <summary>
/// Cast a ray to test if Input.mousePosition is over any UI object in EventSystem.current. This is a replacement
/// for IsPointerOverGameObject() which does not work on Android in 4.6.0f3
/// </summary>
private static bool IsPointerOverUIObject()
{
if (EventSystem.current == null)
return false; // Referencing this code for GraphicRaycaster https://gist.github.com/stramit/ead7ca1f432f3c0f181f
// the ray cast appears to require only eventData.position.
PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
eventDataCurrentPosition.position = new Vector2(Input.mousePosition.x, Input.mousePosition.y); List<RaycastResult> results = new List<RaycastResult>();
EventSystem.current.RaycastAll(eventDataCurrentPosition, results); return results.Count > ;
} /// <summary>
/// Cast a ray to test if screenPosition is over any UI object in canvas. This is a replacement
/// for IsPointerOverGameObject() which does not work on Android in 4.6.0f3
/// </summary>
private bool IsPointerOverUIObject(Canvas canvas, Vector2 screenPosition)
{
if (EventSystem.current == null)
return false; // Referencing this code for GraphicRaycaster https://gist.github.com/stramit/ead7ca1f432f3c0f181f
// the ray cast appears to require only eventData.position.
PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
eventDataCurrentPosition.position = screenPosition; GraphicRaycaster uiRaycaster = canvas.gameObject.GetComponent<GraphicRaycaster>();
List<RaycastResult> results = new List<RaycastResult>();
uiRaycaster.Raycast(eventDataCurrentPosition, results);
return results.Count > ;
}