How to animate RecyclerView height before items are shown

问题

How can I, or should I say when can I animate recyclerView height before items are shown ? I can get the final height in onMeasure but the items always appear too fast and the animation doesn't work.

Any idea on how I could get this animation to work ?

来源：https://stackoverflow.com/questions/38134727/how-to-animate-recyclerview-height-before-items-are-shown