protected override void OnCreate(Bundle savedInstanceState) { base.OnCreate(savedInstanceState); // Set our view from the "main" layout resource SetContentView(Resource.Layout.activity_main); mRecyclerView = FindViewById <RecyclerView>(Resource.Id.recyclerView); AndroidX.AppCompat.Widget.Toolbar toolbar = FindViewById <AndroidX.AppCompat.Widget.Toolbar>(Resource.Id.toolbar); toolbar.InflateMenu(Resource.Menu.main); toolbar.SetOnMenuItemClickListener(this); mRecyclerView.SetLayoutManager(new LinearLayoutManager(this)); mRecyclerView.HasFixedSize = (true); if (savedInstanceState == null) { mHorizontal = true; } else { mHorizontal = savedInstanceState.GetBoolean(ORIENTATION); } SetupAdapter(); }