Android implements timing loop and delay mode

1. Timing cycle

1. handler.postDelayed+Runnable

• First create a Handler object

Handler handler=new Handler();

• Then create a Runnable object

Runnable runnable=new Runnable(){
@Override
public void run(){
// TODO Auto-generated method stub      
  //要做的事情，这里再次调用此Runnable对象，以实现每两秒实现一次的定时器操作       
     handler.postDelayed(this,2000);
    }
};

• Called in the main thread, using the PostDelayed method, call this Runnable object after two seconds

handler.postDelayed(runnable,2000);

• ★ To turn off this timer, you can do this

handler.removeCallbacks(runnable);

2. handler+timer+timeTask

• First create a Handler object

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

• Then create a Timer object

Timer timer =new Timer();
TimerTask timerTask =new TimerTask(){
@Override
public void run(){
Message message =newMessage();
             message.what =1;
             handler.sendMessage(message);
}
};

• Called in the main thread, using the schedule method

//延时1s，每隔500毫秒执行一次run方法
timer.schedule(timerTask,1000,500);

3. Thread+handler

• First create a Handler object

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

• Then create a Timer object

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

• Called in the main thread

new Thread(new ScheduleThread()).start();

Two, delay

1. Handler's postDelayed method:

new Handler().postDelayed(newRunnable(){
@Override
public void run(){//do something
}
},1000);//延时1s执行

2. Timer + TimerTask method:

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

3. Thread method:

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

Reference link: https://www.jianshu.com/p/ea39ffb0f060