how to use "blocking object" in unity 5 ?

Unity Engine
1

hi guys, I tried to add a button in my scene. in the canvas of the button, I set “blocking object” to “all” in the graphic raycaster. In the scene,there is a gameobject with a script,simply code:

if input.getmousebuttondown(0)
{
doSomething();
}

but when I click on the button

I found the click is not blocking,the “dosSomething” is still called

is that a new problem for unity5？.

or, is there another way,when i click on the objects on UI layer, the object on other layer will not triger any event?

2

UI doesn’t block physics raycasts, so GetMouseButtonDown will pass through.

you can check if the click is over a ui element though:

http://docs.unity3d.com/ScriptReference/EventSystems.EventSystem.IsPointerOverGameObject.html

3
4

thanks to all of above
then, should I use event trigger interface for all script which will be attach to a gameObject that under UI?
and,what’s the correct use of “blocking object”?