Q:

android thread: how worker thread send signal to main(GUI) thread?

I have a gui thread starting a new thread to do some busy things. The GUI thread will wait the worker thread to be completed, in the mean time the GUI need to be responsive.
Psedo code:
main thread:
start_thread();
wait_thread_done();
work thread:
doing_sth();
notify_main_thread();
What is the easiest way to do this in android?

A:

The easiest way to do this is with Android's AsyncTask.  The documentation is here
http://developer.android.com/reference/android/os/AsyncTask.html
And you can call Activity.runOnUiThread() to update the UI from your background task.

