onPostExecute not called after completion AsyncTask

Question

For some reason my onPostExecute() is not called after my AsyncTask finishes.

My class decleration:

public class setWallpaper

Answer 1

After having the same problem and none of these answers helped me, I found out that my UI thread was blocked (I used a CountDownLatch.await()) and therefore the onPostExecute() method that is supposed to be called by the UI thread was never called.

Answer 2

Did you start the task with execute() method? The onPostExecute wouldn't run if you just invoke the doInBackground.

Answer 3

I had the same behaviour, and the cause was that I have been posting a lot of messages as a progress inside doInBackground with following code:

new Handler(Looper.getMainLooper()).post(new Runnable() {
   @Override
   public void run() {
     // .. some UI updates
   }
});

this must have overloaded main thrad message queue, and caused long delay before onPostExecute would get called. The solution was to post only once every second.

Answer 4

For me it was user error. I was ending the AsyncTask by invoking cancel(true) on it and not reading the documentation closely enough to know that onPostExecute is not called in this case, onCancelled is.

Answer 5

Found/Made another nasty mistake:

If your params of onPostExecute(Param param) don't match the one you defined with extends AsyncTask<...,...,Param> and you didn't use the @Override annotation, it will never be executed and you don't get a warning from Eclipse.

Note to myself: Just always use the @Override annotation and Eclipse will help you.

Another easy way to avoid all named mistakes:

in Eclipse: Right-click in code > Source > Override/Implement Methods

Answer 6

Did you create your AsyncTask on the UI thread? Also add an @Override annotaiton on your onPostExecute() method to make sure you declared it correctly.