RecyclerView / MapView crashes when rotating device

Issue

I have a Android.Support.V4.Fragment that contains both a MapView and a RecyclerView. These are separate views in the Fragment.

The app crashes when the device is rotated:

Android.OS.BadParcelableException: ClassNotFoundException when unmarshalling: android.support.v7.widget.RecyclerView$SavedState

I am passing the lifecycle methods to the MapView as required by the docs:

private MapView mapView;
private RecyclerView myRecyclerView;
private RecyclerView.LayoutManager myLayoutManager;

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    base.OnCreateView(inflater, container, savedInstanceState);

    myRecyclerView = myRootView.FindViewById<RecyclerView>(Resource.Id.myRecyclerView);
    myLayoutManager = new LinearLayoutManager(activity, LinearLayoutManager.Horizontal, false);
    myRecyclerView.SetLayoutManager(myLayoutManager);
    myRecyclerAdapter = ...
    myRecyclerView.SetAdapter(myRecyclerAdapter);

    mapView.OnCreate(savedInstanceState);
}


public override void OnSaveInstanceState(Bundle outState)
{
    ...
    if (mapView != null) mapView.OnSaveInstanceState(outState);
    base.OnSaveInstanceState(outState);
}

If I remove the RecyclerView form the AXML it rotates correctly, if I include it the app crashes at mapView.OnCreate(savedInstanceState) why is this?

Solution

For anyone that searches and has the same problem. This is the solution, It would appear to be a 2yr old bug.

I was able to get around it by saving the MapView's saved state on a separate Bundle and then adding it to the outgoing saved state bundle. Then in onCreate(), I would just grab the MapView's saved state from the incoming one and pass it into its onCreate() method, thus stopping the crashes.

In my case I implemented as so:

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
{
    base.OnCreateView(inflater, container, savedInstanceState);

    myRecyclerView = myRootView.FindViewById<RecyclerView>(Resource.Id.myRecyclerView);
    myLayoutManager = new LinearLayoutManager(activity, LinearLayoutManager.Horizontal, false);
    myRecyclerView.SetLayoutManager(myLayoutManager);
    myRecyclerAdapter = ...
    myRecyclerView.SetAdapter(myRecyclerAdapter);

    Bundle mapViewSavedInstanceState = savedInstanceState != null ? savedInstanceState.GetBundle("mapViewSaveState") : null;
    mapView.OnCreate(mapViewSavedInstanceState); 
}


public override void OnSaveInstanceState(Bundle outState) 
{
    if (mapView != null)
    { 
        Bundle mapViewSaveState = new Bundle(outState);
        outState.PutBundle("mapViewSaveState", mapViewSaveState);
        mapView.OnSaveInstanceState(outState);

    }
    base.OnSaveInstanceState(outState); 
}

Answered By - tallpaul