Android 定时器 延时器

通过实际项目的练习,掌握了几种android基本定时器和延时的用法,这里我想总结一下作为自己的收获,下面列出的是比较简洁的模式,方便简单地在程序中直接调用。

1.CountDownTimer

public class ZpTimerActivity extends Activity {  
  
    private CountDownTimer mTimer;  
  
    @Override  
    protected void onCreate(@Nullable Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
  
        setContentView(R.layout.activity_timer);  
        initView();  
    }  
  
    private void initView() {  
        if (mTimer == null) {  
            mTimer = new CountDownTimer((long) (5 * 1000), 1000) {  
  
                @Override  
                public void onTick(long millisUntilFinished) {  
                    if (!ZpTimerActivity.this.isFinishing()) {  
                        int remainTime = (int) (millisUntilFinished / 1000L);  
                        Log.e("zpan","======remainTime=====" + remainTime);  
                    }  
                }  
  
                @Override  
                public void onFinish() {  
                    Log.e("zpan","======onFinish=====");  
                }  
            };  
            mTimer.start();  
        }  
    }  
  
    @Override  
    protected void onDestroy() {  
        super.onDestroy();  
        if (mTimer != null) {  
            mTimer.cancel();  
            mTimer = null;  
        }  
    }  
}  

Log:

12-06 16:31:17.809 20276-20276/com.example.zpdemo E/zpan: ======remainTime=====4  
12-06 16:31:18.811 20276-20276/com.example.zpdemo E/zpan: ======remainTime=====3  
12-06 16:31:19.812 20276-20276/com.example.zpdemo E/zpan: ======remainTime=====2  
12-06 16:31:20.813 20276-20276/com.example.zpdemo E/zpan: ======remainTime=====1  
12-06 16:31:22.769 20276-20276/com.example.zpdemo E/zpan: ======onFinish=====  

三种常用的定时器
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();
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