how to populate a listview asynchronously?

Question

I am wondering how I should implement a ListAdapter that loads its views asynchronously into a ListView? I want to do this because I am populating the list with information from my database, which is making my activity a bit slow to load at times.

Answer 1

You can use an AsyncTask and use the onPostExecute methods to publish the newly loaded results:

private ArrayAdapter adapter = new YourArrayAdapter();

private class YourAsyncTask extends AsyncTask<Void, Void, List<YourItem>> {

    @Override
    protected void onPreExecute() {
        // start loading animation maybe?
        adapter.clear(); // clear "old" entries (optional)
    }

    @Override
    protected List<YourItem> doInBackground(Void... params) {
        // everything in here gets executed in a separate thread
        return DataBase.getItems();
    }

    @Override
    protected void onPostExecute(List<YourItem> items) {
        // stop the loading animation or something
        adapter.addAll(items);
    }
}