Android：异步任务线程Hibernate错误

Question

我在StackOverflow的职业生涯中有一个第一个问题。我希望是你帮我。

发生了什么：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.recycler_view, container, false);
    recyclerView = (RecyclerView) view.findViewById(R.id.my_recycler_view);
    textViewErrorMsg = (TextView) view.findViewById(R.id.tv_error_message);
    progressBarLoading = (ProgressBar) view.findViewById(R.id.pb_loading);
    new TakeDates().execute();
    return view;
}

@SuppressLint("StaticFieldLeak")
class TakeDates extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        progressDialog = new ProgressDialog(getActivity());
        progressDialog.getWindow().clearFlags(
                WindowManager.LayoutParams.FLAG_DIM_BEHIND);
        progressDialog.setMessage("Loading places...");
        progressDialog.setCanceledOnTouchOutside(false);
        progressDialog.show();
    }

    @Override
    protected Void doInBackground(Void... voids) {
        try {
            Thread.sleep(2200);
            populateFromJson();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        if (progressDialog.isShowing())
            progressDialog.dismiss();
    }

}

 private void populateFromJson() {
    ConnectivityManager conMgr = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
    assert conMgr != null;
    NetworkInfo i = conMgr.getActiveNetworkInfo();
    if (i != null && i.isConnected() && i.isAvailable()) {
        ApiService api = RetroClient.getApiService(PLACES_URL);

        Call<PlaceList> call = api.getMyJSON();

        call.enqueue(new Callback<PlaceList>() {
            @Override
            public void onResponse(Call<PlaceList> call, Response<PlaceList> response) {
                if (response.isSuccessful()) {
                    itemList = response.body().getItemList();
                    adapter = new RecyclerViewPlaceAdapter(itemList, getContext());
                    recyclerView.setAdapter(adapter);
                    recyclerView.setHasFixedSize(true);
                    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
                    showPlaces();
                } else {
                    showErrorMessage("Try to restart your app.");
                }
            }

            @Override
            public void onFailure(Call<PlaceList> call, Throwable t) {
                showErrorMessage("Here is the main error: " + t.getMessage() + "\nTry to restart your app.");
            }
        });
    } else {
        showErrorMessage("Internet Connection Not Available" + "\nTry to find better connection to the internet.");
    }
}

@Override
    protected Void doInBackground(Void... voids) {
        try {
            Thread.sleep(2200); 
            populateFromJson();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return null;
    }

Answer 1

populateFromJSON()尝试使用recicleview。视图（和视图子类）对象不能从活动线程以外的任何线程使用。

在AsyncTask上执行.execute()时，onpreexecute和onpostexecute将由活动线程执行，doinbackground由子线程执行。

一旦了解了这一点，您就很容易理解，为了避免该错误，您应该在onPostExecute中调用populateFromjson()

N.B.如果您的doInBackground方法真的需要等待，那么有更有效的方法可以做到这一点。看看这里和这里