android - 旋转设备时 RecyclerView/MapView 崩溃

Question

我有一个 Android.Support.V4.Fragment，其中包含一个 MapView 和一个 RecyclerView。这些是 Fragment 中的独立 View 。

设备旋转时应用崩溃:

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

我按照文档的要求将生命周期方法传递给 MapView:

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);
}

如果我从 AXML 中删除 RecyclerView，它会正确旋转，如果我包含它，应用程序会在 mapView.OnCreate(savedInstanceState) 崩溃，这是为什么？

Answer 1

对于搜索并遇到相同问题的任何人。 This is the solution , 这似乎是一个 2 年前的错误。

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.

在我的例子中，我是这样实现的:

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); 
}