AsyncTask: where does the return value of doInBackground() go?

Question

When calling AsyncTask<Integer,Integer,Boolean>, where is the return value of:

protected Boolean doInBackground(Integer... params)?

Usually we start AsyncTask with new AsyncTaskClassName().execute(param1,param2......); but it doesn't appear to return a value.

Where can the return value of doInBackground() be found?

Answer 1

The value is then available in onPostExecute which you may want to override in order to work with the result.

Here is example code snippet from Google's docs:

 private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {       protected Long doInBackground(URL... urls) {           int count = urls.length;           long totalSize = 0;           for (int i = 0; i < count; i++) {               totalSize += Downloader.downloadFile(urls[i]);               publishProgress((int) ((i / (float) count) * 100));           }           return totalSize;       }        protected void onProgressUpdate(Integer... progress) {           setProgressPercent(progress[0]);       }        protected void onPostExecute(Long result) {           showDialog("Downloaded " + result + " bytes");       }  }