Question

I have a Main activity with a few methods.

• GetTopics: calls REST API and returns JSON results
• BindTopics: displays the results from GetTopics on the screen

There are a few others with similar functionality, but I’m sure I can fit the solution to these across all methods.

Question: What is the proper way to run these in separate threads? Should both of them be in the same thread? Should I call BindTopics once GetTopics is complete?

Either way, doesn’t the UI get built prior to the async threads are completed? If so, how do I update the UI?

Any help is appreciated.

Answer 1

I would load it in a progress dialog with an AsyncTask. You will need to declare the handler to update controls in the UI thread.

Example:

private Handler     handler         = new Handler();


final ProgressDialog pd = new ProgressDialog(this);
pd.setTitle("Getting topics..");
pd.setMessage("Please while topics are retrieved");
pd.setProgressStyle(ProgressDialog.STYLE_SPINNER);
pd.setIndeterminate(true);

new AsyncTask<Void, Void, Void>() {

    @Override
    protected Void doInBackground(Void... params) {

        GetTopics();

        return null;
    }

    @Override
    protected void onPreExecute() {

        pd.show();
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(Void result) {

        BindTopics();

        pd.dismiss();

        handler.post(new Runnable() {

            public void run() {
                // update UI
                // remove loading view
                // load details of topics
            }
        });
        super.onPostExecute(result);
    }

}.execute();