Android: how to use SystemClock.elapsedRealtime() to show second one by one?

Question

I am using the SystemClock.elapsedRealtime() to display the time.

But now I want to show the seconds one-by-one to be increase based on the SystemClock.elapsedRealtime() time.
And yes I must use the thred.

So how to do it ?

I have tried it with this thread:

// Start lengthy operation in a background thread
progressThread = new Thread(new Runnable() {

    public void run() {
        while (mProgressStatus < 1000) {
            mProgressStatus = ((int) (SystemClock.elapsedRealtime() / 10));
            // Update the progress bar
            mHandler.post(new Runnable() {

                public void run() {   
                    // try {
                    //  // progressThread.sleep(1000);
                    // } catch (InterruptedException e) {
                    //  // TODO Auto-generated catch block
                    //  e.printStackTrace();
                    // }
                    // progressBar.setProgress(mProgressStatus);
                    System.out.println("SECOND is :" + mProgressStatus);
                }
            });
        }
    }
});

So what should I change in this thread to get seconds one by one to be increased ??

Please help me for this.

Thanks.

Answer 1

You can use the Chronometer class. You can bind it to SystemClock.elapsedRealtime() using setBase() . Another way could be if you use Handler inside an Activity and using the sendEmptyMessageDelayed() method with value 1000 to update your timer.

Answer 2

If you want to use a second thread to get the elapsed time (as you have done) then you MUST employ some method to notify your Activity's main thread that the canvas must be re-painted, as mentioned here and in here.

You could also employ a Handler which has been instantiated in your Activities Main thread. From your second thread (which gets the system time) you send a Message which contains the system time to the Handler. Because the Handler runs in the Main thread it is safe to alter Views from here. I would doubt that this is an accurate way of displaying system time on Android ie I would think there's a better way.