in 4.6RC1 uGUI, sprites blocks buttons/scrollrect from clicking/scrolling

(sorry my English wasn’t very good…)
I built a scene with 4.6 RC1, as the pictures 1 & 2

picture 1:

picture 2:

players could scroll the scene to left or right to see more levels(by using a invisible ScrollRect)
each level was Instantiated from prefab, put under a GridLayoutGroup, and contains a button for player to click
at the front side were sea waves.

now here comes the problem:

  1. for now, i put scrollview behind level buttons and sea waves. so only 1/3 of the screen could respond the scroll, even the sea waves would block the scrollview
  2. if i put scrollview before level buttons, i can’t trigger buttons any more. any idea how to make them together peaceful?

ps:
i also try to settle this problem through physics2D layer collision matrix, but didn’t work (or maybe it’s my own problem beacuse i’m not quite understand it yet)
and i also tried setting the GraphicRaycaster script on canvas, but also didn’t change anything(and that’s really wired)

Hey guys! Just had a lot of problems with this - in Unity3d 5
event triggers will NOT work (you won’t be able to drag) - use good ole buttons!!!

For the waves in the front, you should check the answer I gave to this question.

As for your buttons, maybe you’ll need to write your own ICanvasRaycastFilter. But I’m not sure what you are trying to achieve. Since how do the buttons and the scrollrect need to co-operate, and how do they work now (If you put buttons in front of scrollrect)