If you use Android's JUnit test runner, you can use the @OnUiThread annotation to run a test on the UI thread :)
On Mon, Aug 9, 2010 at 8:55 AM, Streets Of Boston <[email protected]> wrote: > I had a similar problem. The problem i had was in JUnit tests, which > run in non-UI threads, causing AsyncTasks to be loaded in non-UI > threads and i got the same error message. However, as long as you > create your process' first AsyncTask in a UI-thread, all next ones can > be created in non-UI threads. > > This is what i did in my JUnit tests: > > First some 'static' code calls this method below as soon as possible, > which creates a dummy AsyncTask that is never executed. It just makes > sure that the Looper for every AsyncTask is created in a UI-thread. > public static synchronized void initialize(Instrumentation inst) { > if (hasBeenInitialized) > return; > > // Just to load AsyncTask in the main UI thread.... > // If the first AsyncTask instance is loaded in any other thread, UI- > callbacks will never work. > inst.runOnMainSync(new Runnable() { > public void run() { > Object dummy = new AsyncTask<Void,Void,Void>() { > protected Void > doInBackground(Void... params) { return null; } }; > } > }); > hasBeenInitialized = true; > } > > After this method has been called, AsyncTasks can be created from non- > UI threads. > > If you don't deal with JUnit tests and such, just make sure that your > first (dummy) AsyncTask instance is created in a UI-thread (e.g > onCreate). All subsequent ones can be created in non-UI threads. > > However, TreKing's comments about calling performTask when your > service starts is still very valid :-) > > > On Aug 9, 7:06 am, Samuh <[email protected]> wrote: >> I have a helper class that contains definition of an AsyncTask(inner >> class). Other classes instantiate this class and call one of its >> method which in turn instantiates, the AsyncTask and starts execution. >> >> class TaskManager{ >> >> private class SomeTask extends AsyncTask<>{} >> >> public void performTask(){ >> new SomeTask().execute(); >> >> } >> } >> >> //usage: new TaskManager().performTask(); >> >> I schedule Alarms which when triggered start a Service. When the >> service starts it creates a Runnable and enqueues it in the work >> queue. From this Runnable, I want to instantiate my helper class and >> start execution of the AsynTask. >> >> The problem is AsyncTask needs to be instantiated from main UI thread >> I am getting errors as soon as the spawned thread calls the method of >> the helper class. The exception is that AsyncTask cannot be called >> from a thread that hasnt called Looper.prepare(). >> >> How do I avoid this? > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > -- Romain Guy Android framework engineer [email protected] Note: please don't send private questions to me, as I don't have time to provide private support. All such questions should be posted on public forums, where I and others can see and answer them -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
