Question

I’m currently using the following code to show / hide a ProgressDialog in my Andorid app (called from withing MyActivity):

private void startTask() {
    new MyTask().execute();
}

private class MyTask extends AsyncTask<A, String, C> {
    private ProgressDialog pd;
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        this.pd = ProgressDialog.show(MyActivity.this, "Title", "Message", true, true);
        pd.setOnCancelListener(new OnCancelListener() {
            public void onCancel(DialogInterface dialog) {
                MyTask.this.cancel(true);
            }
        });

    }

    @Override
    protected void onProgressUpdate(String... values) {
        super.onProgressUpdate(values);
        this.pd.setMessage(values[0]);
    }

    @Override
    protected void onCancelled() {
        super.onCancelled();
        Toast.makeText(MyActivity.this, "cancelled", Toast.LENGTH_SHORT).show();
    }

    @Override
    protected void onPostExecute(RequestResult result) {
        super.onPostExecute(result);
        this.pd.dismiss();
    }
}

Now, since I read so much about onCreateDialog in Activities, I just want to know if my way of doing it has any downsides I didn’t think of, or even why I should prefer the onCreateDialog mechanism.

Answer 1

[UPDATED]

The problem with this approach is that in case Activity will be destroyed (e.g. on rotation) your AsyncTask will retain it in memory, thus create a temporary memory leak. Also, it will cause an IllegalArgumentException while attempting to access ProgressDialog after activity’s onDestroy().