How Can I Monitor The Event Of ScrollRect?

For new uGUI in unity4.6, I use the ScrollRect component to make a page effect, but I don’t know how to monitor the event, just like “OnBeginDrag”, “OnDrag”, or “OnEndDrag” and do some thing when the event happens.Thank you!

I found the solution,haha!NewUI system support 3 interfaces about drag event, IBeginDragHandler,IDragHandler, IEndDragHandler.You can monitor the event as long as you inherit the correspond interface.