回收器视图未更新，日志表示viewrootimpl：sendUserActionEvent（）mView==null

Question

我知道这个问题已经被问了很多次，我已经尝试了这里和这里建议的所有方法，但我仍然不能解决这个问题，所以我在这里再问一次。

12-26 23:46:13.890 1509-1509/com.example.vuclip.gallaryapp D/ViewRootImpl: #3 mView = null

12-26 23:46:13.910 1509-1509/com.example.vuclip.gallaryapp E/ViewRootImpl: sendUserActionEvent() mView == null

我可以添加我的代码，如果你们想，但我不认为有任何错误在我的代码。请帮我做这个，谢谢。

更新

//Main activity
public class MainActivity extends AppCompatActivity {

private static final String TAG = MainActivity.class.getSimpleName();
private static final String apiURL = "http://api.androidhive.info/json/glide.json";
private RecyclerView recyclerView;
private ArrayList<Image> images;
private ProgressDialog pDialog;
private MyRecyclerAdapter mAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    pDialog = new ProgressDialog(this);
    images = new ArrayList<>();

    mAdapter = new MyRecyclerAdapter(images, getApplicationContext());
    RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getApplicationContext(), 2);
    recyclerView.setLayoutManager(layoutManager);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setAdapter(mAdapter);

    fetchImages(apiURL);
}


private void fetchImages(String url) {
    new JSONDownloader().execute(url);
}

private void parseJson(String jsonString) {
    Log.d(TAG, "parseJson: json = " + jsonString);
    images.clear();
    JSONParser parser = new JSONParser(jsonString);
    images = parser.parse();
    mAdapter.notifyDataSetChanged();
}

private class JSONDownloader extends AsyncTask<String, Void, String> {
    @Override
    protected void onPreExecute() {
        pDialog.setMessage("Downloading JSON");
        pDialog.show();
    }

    @Override
    protected String doInBackground(String... params) {
       String json = "";
        try {
            HttpHelper http = new HttpHelper(new URL(params[0]));
            json = http.getJSON();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        Log.d(TAG, "doInBackground: json received = " + json);
        return json;
    }

    @Override
    protected void onPostExecute(String response) {
        if (pDialog.isShowing()) pDialog.cancel();

        parseJson(response);
    }
    }
}

回收器适配器

public class MyRecyclerAdapter extends RecyclerView.Adapter<MyRecyclerAdapter.MyViewHolder>{
private static final String TAG = MyRecyclerAdapter.class.getSimpleName();
private List<Image> images;
private Context context;

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.gallery_thumbnail,parent,false);
    return new MyViewHolder(view);
}

@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
    Image image = images.get(position);
    Log.d(TAG, "onBindViewHolder: image URL = " + image.getMedium_thumb_url());
    Glide.with(context)
            .load(image.getMedium_thumb_url())
            .thumbnail(0.5f)
            .crossFade()
            .into(holder.imageView);
}

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

class MyViewHolder extends RecyclerView.ViewHolder{

    private ImageView imageView;
    public MyViewHolder(View itemView) {
        super(itemView);
        imageView = (ImageView) itemView.findViewById(R.id.thumbnail);
    }
}

public MyRecyclerAdapter(List<Image> images, Context context) {
    this.images = images;
    this.context = context;
}
}

Answer 1

您正在创建ArrayList的新引用，这与您在RecycerView的适配器上设置的引用不同。

而是使用。addall（）属性创建新的引用。

private void parseJson(String jsonString) {
   Log.d(TAG, "parseJson: json = " + jsonString);
   images.clear();
   JSONParser parser = new JSONParser(jsonString);
   // Use .addAll and avoid new refernce
   images.addAll(parser.parse());
   mAdapter.notifyDataSetChanged();
}