AsyncTask onPostExecute never gets called

Note that if you cancel the task via cancel(), onPostExecute() won't be called. Pretty logical, but simply overlooking a call to that method had me stumped.

I had a similiar problem just now. I was extending AsyncTask<Integer,Integer,Integer> and my onPostExecute method looked like:

protected void onPostExecute(int result)

This seemed OK to me, but then again I'm more of a .NET guy than a Java guy. I changed it to:

protected void onPostExecute(Integer result)

because for some reason Java thinks there is a difference between int and Integer?

I think that your problem is that you're declaring the return type as void in your:

extends<Void,Void,Void>

That means no params, no progress and no result. If you want to execute something when it's done, I think you need to give it some kind of value like and integer or a boolean.

If you change your extends to:

<Void,Void,Integer>

Now your passing no params, not publishing any progress, but are returning a value. Change your onPostExecute method to accept an Integer:

protected void onPostExecute(Integer result)

Then change the return in your doInBackground method to something like:

return 1;

Then it should execute for you.

There's one more gotcha about AsyncTasks that I just spent half the day on:

The AsyncTask class must be loaded on the UI thread. This is done automatically as of JELLY_BEAN.

Says the documentation. On Gingerbread (and probably before), given the right circumstances, this leads to onPostExecute not being run. The solution, however, is easy, just a

new MyAsyncTask();

early in the UI thread so the class gets loaded before anything in the background can inadvertently load it.

I had used a static function in my AsyncTask subclass from a background thread that, depending on timing, got called before anything on the UI thread used that AsyncTask subclass, and bingo, a nice Heisenbug.

(Bear with me for answering this old, already answered question, but I didn't find that tidbit of info anywhere, and this is my first post)

My problem was that somehow I didn't @Override the onPostExecute method correctly. I fixed that by clicking right mouse button->source-> Override\Implement method.

Hopes it helps someone