java - E/RecyclerView : No adapter attached; skipping layout D/OpenGLRenderer: eglDestroySurface = 0x730c9a02d0

Question

我遇到了有关 Recyclerview 未连接适配器的问题。这是我的定位:

E/RecyclerView: No adapter attached; skipping layout
D/OpenGLRenderer: eglDestroySurface = 0x730c9a02d0
D/ViewRootImpl@8aa7e83[AddPostActivity]: Relayout returned: old=[0,0] 
[1080,1920] new=[0,0][1080,1920] result=0x5 surface={valid=false 0} 
changed=true
W/ClassMapper: No setter/field for YtyKXov13lReyirA8U4iritiUs6220-July- 
201910: 39 found on class gurungdinesh.com.sisapen.ModelPost
W/ClassMapper: No setter/field for pdMZtSaxkzd5Uul592qwXKawnaI220-July- 
201910: 40 found on class gurungdinesh.com.sisapen.ModelPost
D/FA: Connected to remote service
V/FA: Processing queued up service tasks: 4
I/zygote64: Do partial code cache collection, code=498KB, data=332KB
I/zygote64: After code cache collection, code=498KB, data=332KB
I/zygote64: Increasing code cache capacity to 2MB
D/ViewRootImpl@f8f3e40[MainActivity2]: MSG_RESIZED_REPORT: frame=Rect(0, 
0 - 1080, 1920) ci=Rect(0, 72 - 0, 0) vi=Rect(0, 72 - 0, 0) or=1
MSG_WINDOW_FOCUS_CHANGED 1

这是我的适配器:

public class AdapterPost extends  
RecyclerView.Adapter<AdapterPost.MyHolder> {

Context context;
List<ModelPost> postList;

public AdapterPost(Context context, List<ModelPost>postList) {
this.context = context;
this.postList = postList;

}


@NonNull
@Override
public MyHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int 
viewType) {

//inflate layout
    View view = 
LayoutInflater.from(context).inflate(R.layout.activity_users_posts, 
viewGroup, false);

    return new MyHolder(view);
}

@Override
public void onBindViewHolder(@NonNull MyHolder myHolder, int i) {
//get data
    String fullname = postList.get(i).getFullname();
    String date = postList.get(i).getDate();
    String time = postList.get(i).getTime();
    String Title = postList.get(i).getTitle();
    String Writing = postList.get(i).getWriting();

    //set data
    myHolder.uNameTv.setText(fullname);
    myHolder.pTimeTv.setText(time);
    myHolder.pDate.setText(date);
    myHolder.pTitileTv.setText(Title);
    myHolder.pWritingTv.setText(Writing);


}

@Override
public int getItemCount() {
    return postList.size();
}

//view holder class
class MyHolder extends RecyclerView.ViewHolder
{
    //views from users post
    ImageButton moreBtn;
    CircularImageView uPictureIv;
    TextView uNameTv, pTimeTv, pTitileTv, pWritingTv, pLikesTv, pDate;
    Button likebtn, commentBtn, shareBtn;

    private MyHolder(@NonNull View itemView) {
        super(itemView);

        //init views
        uPictureIv = itemView.findViewById(R.id.uPictureTv);
        uNameTv = itemView.findViewById(R.id.uNameTv);
        pTimeTv = itemView.findViewById(R.id.pTimeTv);
        moreBtn = itemView.findViewById(R.id.moreBtn);
        pDate = itemView.findViewById(R.id.pDateTv);
        pTitileTv = itemView.findViewById(R.id.pTitleTv);
        pWritingTv = itemView.findViewById(R.id.pWriting);
        pLikesTv = itemView.findViewById(R.id.pLikesTv);
        likebtn = itemView.findViewById(R.id.likeBtn);
        commentBtn = itemView.findViewById(R.id.commentBtn);
        shareBtn = itemView.findViewById(R.id.shareBtn);

    }

这是我的 HomeFragment:

public class HomeFragment extends Fragment {
private FirebaseAuth mFirebase;
private DatabaseReference databaseReference;


private RecyclerView recyclerView;
private List<ModelPost> postList;
private AdapterPost adapterPost;


@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable 
ViewGroup container, @Nullable Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.home_activity, container, 
false);


    //init
    mFirebase = FirebaseAuth.getInstance();
    databaseReference = 
 FirebaseDatabase.getInstance().getReference("posts");

    recyclerView = view.findViewById(R.id.all_user_post_list);

    LinearLayoutManager layoutManager = new 
LinearLayoutManager(getActivity());
    layoutManager.setStackFromEnd(true);
    layoutManager.setReverseLayout(true);
    recyclerView.setLayoutManager(layoutManager);

    postList = new ArrayList<>();

    loadPosts();

    return view;
}

private void loadPosts() {
    databaseReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


            postList.clear();
            for (DataSnapshot ds : dataSnapshot.getChildren()) {
                ModelPost modelPost = ds.getValue(ModelPost.class);

                postList.add(modelPost);

                //adapter
                adapterPost = new AdapterPost(getActivity(), postList);
                //set adapter to RecyclerView
                recyclerView.setAdapter(adapterPost);


            }

        }


        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

            //in case of error
            Toast.makeText(getActivity(), "" + 
databaseError.getMessage(), Toast.LENGTH_SHORT).show();
        }
    });

我尝试了很多事情，但什么也没发生。

Answer 1

由于 Firebase 任务是异步的，因此在 onCreateView 方法中的 return view; 后调用 setAdapter 方法。这就是为什么它会给出错误未连接适配器。您可以做的是在 onCreateView 方法中调用 setAdapter ，并在填充列表后，调用 notifyDataSetChanged() 。请参阅下面的代码

public class HomeFragment extends Fragment {

    private FirebaseAuth mFirebase;
    private DatabaseReference databaseReference;

    private RecyclerView recyclerView;
    private List<ModelPost> postList;
    private AdapterPost adapterPost;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable
            ViewGroup container, @Nullable Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.home_activity, container,
                false);

        //init
        mFirebase = FirebaseAuth.getInstance();
        databaseReference =
                FirebaseDatabase.getInstance().getReference("posts");

        recyclerView = view.findViewById(R.id.all_user_post_list);

        LinearLayoutManager layoutManager = new
                LinearLayoutManager(getActivity());
        layoutManager.setStackFromEnd(true);
        layoutManager.setReverseLayout(true);
        recyclerView.setLayoutManager(layoutManager);

        postList = new ArrayList<>();
        // ----------- set the adapter here --------------------
        adapterPost = new AdapterPost(getActivity(), postList);
        recyclerView.setAdapter(adapterPost);

        loadPosts();

        return view;
    }

    private void loadPosts() {
        databaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                postList.clear();
                for (DataSnapshot ds : dataSnapshot.getChildren()) {
                    ModelPost modelPost = ds.getValue(ModelPost.class);
                    postList.add(modelPost);
                }
                // ----------- call notifyDataSetChanged --------------------
                adapterPost.notifyDataSetChanged()

            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

                //in case of error
                Toast.makeText(getActivity(), "" +
                        databaseError.getMessage(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}