Android计时器

1.Handler类的postDelayed方法：

         Handler mHandler = new Handler();
                 Runnable r = new Runnable() {

                    @Override
                    public void run() {
                            //do something
                            //每隔1s循环执行run方法
                            mHandler.postDelayed(this, 1000);
                    }
                };


主线程中调用：  mHandler.postDelayed(r, 100);//延时100毫秒

2.用handler+timer+timeTask方法：

      Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == 1){
                //do something
            }
            super.handleMessage(msg);
        }
    };

    Timer timer = new Timer();
    TimerTask timerTask = new TimerTask() {
        @Override
        public void run() {
            Message message = new Message();
            message.what = 1;
            handler.sendMessage(message);
        }
    };
 主线程中调用：timer.schedule(timerTask,1000,500);//延时1s，每隔500毫秒执行一次run方法

3.Thread+handler方法：

 Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == 1){
                //do something
            }
            super.handleMessage(msg);

        }
    };

    class MyThread extends Thread {//这里也可用Runnable接口实现
        @Override
        public void run() {
            while (true){
                try {
                    Thread.sleep(1000);//每隔1s执行一次
                    Message msg = new Message();
                    msg.what = 1;
                    handler.sendMessage(msg);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

            }
        }
    }
主线程中调用：new Thread(new MyThread()).start();
二、三种延时的快捷方法： 
1.Handler的postDelayed方法：

new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
              //do something
          }
       }, 1000);    //延时1s执行

2.timer + TimerTask方法：

                 timer = new Timer();
                 timer.schedule(new TimerTask() {                   
                    @Override
                    public void run() {
                          //do something
                    }
                },1000);//延时1s执行

3.Thread方法：

        new Thread(new MyThread()).start();
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(1000);//延时1s
                    //do something
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();