CODEWITHSUNDEEP
androidandroid-asynctaskandroid-recyclerview
Aaron Strickland
Aaron Strickland

Reputation: 91

Where to setAdapter in AsyncTask?

I'm trying to improve the performance of my mobile App. I'm attempting to use AsyncTask. I've looked at quite a lot of documentation on AsyncTask, also looked at numerous questions on here, but can't seem to get my code to run correctly.

I've seen examples where the Adapter is set in the onPostExecute method, but that does not work for me.. 

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



        Twitter.initialize(this);

        new getTweets().execute();
    }


private class getTweets extends AsyncTask<Void, Void, Void>{


    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        final RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(travel_updates.this));
    }

    @Override
    protected Void doInBackground(Void... params) {
        final UserTimeline searchTimeline = new UserTimeline.Builder().screenName("TflTravelAlerts")
                .maxItemsPerRequest(5)
                .build();

        final TweetTimelineRecyclerViewAdapter tweetAdapter =
                new TweetTimelineRecyclerViewAdapter.Builder(travel_updates.this)
                        .setTimeline(searchTimeline)
                        .setViewStyle(R.style.tw__TweetLightWithActionsStyle)
                        .build();
        return null;
    }

    @Override
    protected void onPostExecute(Void Void) {

recyclerView.setAdapter(tweetAdapter);

    }
  }
}

Thanks

Upvotes: 1

Views: 1657

Answers (1)

Barns
Barns

Reputation: 4848

Define your RecycleView in your MainActivity not in the onPreExecute method of your AsyncTask.

With in your onCreate method you can set the RecyclerView.

private RecyclerView recyclerView;


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

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    recyclerView.setLayoutManager(new LinearLayoutManager(travel_updates.this));

    Twitter.initialize(this);

    new getTweets().execute();
}

Because you have UserTimeline and TweetTimelineRecyclerViewAdapter inside the doInBackground method (which is not on the same Thread as you UI) you cannot set the adapter in doInBackground. Set the adapter on the UI thread.

@Override
protected Void doInBackground(Void... params) {
    final UserTimeline searchTimeline = new UserTimeline.Builder().screenName("TflTravelAlerts")
            .maxItemsPerRequest(5)
            .build();

    final TweetTimelineRecyclerViewAdapter tweetAdapter =
            new TweetTimelineRecyclerViewAdapter.Builder(travel_updates.this)
                    .setTimeline(searchTimeline)
                    .setViewStyle(R.style.tw__TweetLightWithActionsStyle)
                    .build();

     runOnUiThread(new Runnable() {
        @Override
        public void run() {
            recyclerView.setAdapter(tweetAdapter);
    });

    // I don't think you need to return anything if your method uses void??
    return null;
}

Then onPostExecute should be empty.

Upvotes: 1

Related Questions