Handler耗时操作，不开启线程

开启线程太消耗资源，所以不开启线程做handler耗时操作
handler对象

 private Handler handler = new Handler(new Handler.Callback() {        @Override        public boolean handleMessage(Message message) { //handler处理message的过程            switch (message.what) {                case 0:                    textView.setText(String.valueOf(message.arg1));                    message.arg1++;                    if (message.arg1 < 100) {                        handler.sendMessageDelayed(Message.obtain(message), 1000);//延时发送                    }                    break;            }            return true;        }    });

发送消息

  handler.obtainMessage(0, 0, 0).sendToTarget();