Rendering Problems: java.lang.NullPointerException at android.support.v7.widget.RecyclerView in Android Studio 1.1.0

Question

I have recently updated android sdk to api 22 and android studio 1.1.0. After that I am getting rendering issues on RecyclerView. Here is what I am getting

Answer 1

I have had the same error. line 1216 of RecyclerView is:

return mLayout.canScrollVertically() ? mLayout.computeVerticalScrollRange(mState) : 0;

mLayout being null at the time is the issue, I am not sure why it is null, but it appears you have to call setLayoutManager() on your RecyclerView immediately after setContentView() or inflate(). My code was running a background thread before I tried to access the RecyclerView and call its setLayoutManager(). Once I changed to the following, it works

i.e.

this.setContentView(R.layout.schedule);
rv = (RecyclerView) this.findViewById(R.id.schedule_listview);
rv.setLayoutManager(new LinearLayoutManager(this));

I am still not quite understand why have to do that though