Waiting for ASyncTask to finish or variable to be set

Question

I am trying to set a variable in an activity to the result of my AsyncTask. I have read that I cannot return a variable and that I would have to set up the variable in my activity and then change it in the onPostExecute method.

My problem is that after the AsyncTask finishes I need to use that variable. I am having trouble with this because all the solutions I have tried so far cause the UI to freeze up and then go non-responding.

What I have tried so far:

while (!task.isCancelled()) {
    // Wait... 
}

And

while (variable == null) { 
    // Wait ...
}

Is what I am doing the best way to pass a variable from the AsyncTask to my Activity? If it is then how can I wait for the task to finish in the activity without locking up the UI?

Answer 1

If you are dependent on the result of an AsyncTask, you can do this.

Object result = asyncTask.execute().get();

The type of the result is the return type in your doInBackground() method. But then your main thread will be waiting until the task is complete.