How do we use runOnUiThread in Android?

Question

I\'m new to Android and I\'m trying to use the UI-Thread, so I\'ve written a simple test activity. But I think I\'ve misunderstood something, because on clicking the button

Answer 1

Below is corrected Snippet of runThread Function.

private void runThread() {

    new Thread() {
        public void run() {
            while (i++ < 1000) {
                try {
                    runOnUiThread(new Runnable() {

                        @Override
                        public void run() {
                            btn.setText("#" + i);
                        }
                    });
                    Thread.sleep(300);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }.start();
}