问题
Hi I'm having an issue with the new Android Lollipop RecyclerView
It keeps crashing with the following exception:
Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView$LayoutManager.onMeasure(android.support.v7.widget.RecyclerView$Recycler, android.support.v7.widget.RecyclerView$State, int, int)' on a null object reference
Full stack trace can found here
The code used to initiate the RecyclerView is the same mostly the same as the tutorial, however for some reason this still complains. Any help would be greatly appreciated.
The code can be accessed at: gist here and layout: this gist
None of the views, or objects are null
回答1:
Add the following code:
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
Before adding adapter:
recyclerView.setAdapter(adapter);
回答2:
In the android Api level 22 it will not give the error. Instead it skips the layout if the Adapter is not found.
By showing the warning:
RecyclerView﹕ No adapter attached; skipping layout
But your app will not crash and runs, but recyclerView doesn't shown.
来源：https://stackoverflow.com/questions/26446162/android-recyclerview-layoutmanager-exception