CODEWITHSUNDEEP
androidmultithreadingandroid-asynctask
Kaloyan Roussev
Kaloyan Roussev

Reputation: 14711

How to execute and receive results from AsyncTasks outside of the main thread?

I have a bunch of AsyncTasks and their callbacks (listener interfaces) that I dont want to have anything to do with the UI thread.

Reading the answer here: Android : can AsyncTask return in another thread than UI thread? I am left with the impressin that I can only start AsyncTasks from the UI Thread which means the callbacks that I invoke from their onPostExecute methods will also be in the main thread.

How do I move all this logic away from the UI thread?

Upvotes: 1

Views: 110

Answers (1)

ajpolt
ajpolt

Reputation: 1002

First, based on some issues I've had before when trying to run AsyncTasks in an IntentService, I think your assumption that you cannot run an AsyncTask from a non-UI thread is false.

The problem I've found with starting AsyncTasks off the UI thread is not that they don't run or that they cause crashes, but that onPostExecute() doesn't automatically run on the main UI thread after the other stuff finishes. I wouldn't recommend doing it, but you probably could if you wanted to.

But the whole reason AsyncTasks exist are basically to have an easy way to run some code off the UI thread and then be able to alter UI stuff after it's finished. So if you don't want to do anything at all with the UI thread, you shouldn't need to use an AsyncTask at all. If you don't need to run any code on the UI thread, you can just use something like:

new Thread(new Runnable() {
        public void run() {
            //Do your stuff
        }
}).start();

Upvotes: 3

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