new Thread() {
        public void run() {
            Message message = Message.obtain();
            try {

                Thread.sleep(2000);
                message.what = GO_HOME;
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            handler.sendMessage(message);
        }
    }.start();

private Handler handler = new Handler() {
    /**
     * 當handler 發送的消息需要在主線程執行時，調用此方法
     */
    public void handleMessage(android.os.Message msg) {
        switch (msg.what) {
            case GO_HOME:
              break;
        }
    };
};