Question

I need a timer which will send a message for its’ handler. I’ve made a class that implements Runnable and I feed its’ object to the thread runnable constructor. When I start the thread it hangs application and it obviously isn’t working asyncroniously. I could’ve used AsyncTask but I’ve also heard that they’re designed for short-term operations while my background timer must work throughout activity onResumed state. Would you mind pointing out my mistake and maybe giving useful links on the subject of threads in android. Thanks.

Here’s the code I’ve written:

@Override
public void onResume() {
    // TODO Auto-generated method stub
    super.onResume();

    _myTimerInstance = new MyTimer(new Handler() {
        @Override
        public void dispatchMessage(Message msg) {
            super.dispatchMessage(msg);
            // ...
        }
    });
    _myThread = new Thread(_myTimerInstance);
    _myThread.run();


}

private static class MyTimer implements Runnable {

    private Handler _myHandler;
    private boolean _activityHasBeenLeft;

    public MyTimer(Handler myHandler) {
        _myHandler = myHandler;
    }

    public void setActivityHasBeenLeft(boolean b) {
        _activityHasBeenLeft = b;
    }

    @Override
    public void run() {
        while (!_activityHasBeenLeft) {
            try {
                Thread.sleep(2000);
                _myHandler.sendEmptyMessage(0);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

Answer 1

You should always use Thread.start() not Thread.run()
Thread.run() is like a normal method call and is run on the same thread.

use

_myThread.start();