I spent a moment trying to figure out a way to add a header to a RecyclerView, unsuccessfully. This is what I got so far :

@Override protected void onCreate(Bundle savedInstanceState) { ... layouManager = new LinearLayoutManager(getActivity()); recyclerView.setLayoutManager(layouManager); LayoutInflater inflater = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE); headerPlaceHolder = inflater.inflate(R.layout.view_header_holder_medium, null, false); layouManager.addView(headerPlaceHolder, 0); ... } 

The LayoutManager seems to be the object handling the disposition of the RecyclerView items. As I couldn't find any addHeaderView(View view) method, I decided to go with the LayoutManager's addView(View view, int position) method and to add my header view in first position to act like a header.

Aaand this is where things get uglier :

java.lang.NullPointerException: Attempt to read from field 'android.support.v7.widget.RecyclerView$ViewHolder android.support.v7.widget.RecyclerView$LayoutParams.mViewHolder' on a null object reference at android.support.v7.widget.RecyclerView.getChildViewHolderInt(RecyclerView.java:2497) at android.support.v7.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:4807) at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:4803) at com.mathieumaree.showz.fragments.CategoryFragment.setRecyclerView(CategoryFragment.java:231) at com.mathieumaree.showz.fragments.CategoryFragment.access$200(CategoryFragment.java:47) at com.mathieumaree.showz.fragments.CategoryFragment$2.success(CategoryFragment.java:201) at com.mathieumaree.showz.fragments.CategoryFragment$2.success(CategoryFragment.java:196) at retrofit.CallbackRunnable$1.run(CallbackRunnable.java:41) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5221) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 

After getting several NullPointerExceptions trying to call the addView(View view) at different moments of the Activity creation (also tried adding the view once everything is set up, even the Adapter's data), I realized I have no idea if this is the right way to do it (and it doesn't look to be).

Could somebody help me? Or at least give me some idea / new direction to explore?

Thanks in advance!

VieuMa

PS: Also, a solution that could handle the GridLayoutManager in addition to the LinearLayoutManager would be really appreciated!