个人备案的网站 做企业站,2345网址导航手机版下载安装,常州做网站公司有哪些,新校区建设网站管理规定总结了以下六种常用的Android延时执行策略#xff0c;以此记录#xff1a;
1、TimerTask
2、Handler.postDelayed
3、Handler.sendEnptyMessageDelayeed
4、Thread.sleep线程休眠-需要在子线程
5、使用AlarmManager-全局定时器或者闹钟
6、Wait
首先定义一个时间常量以此记录
1、TimerTask
2、Handler.postDelayed
3、Handler.sendEnptyMessageDelayeed
4、Thread.sleep线程休眠-需要在子线程
5、使用AlarmManager-全局定时器或者闹钟
6、Wait
首先定义一个时间常量
public static final long DELAYTIME 2000L;
1、TimerTask
TimerTask mTimerTask new TimerTask() {Overridepublic void run() {Log.e(TAG, TimerTask -run:);}};
//timer可以复用timerTask不可复用否则闪退
if (mTimer null){mTimer new Timer();
}
mTimer.schedule(mTimerTask,DELAYTIME);Handler.postDelayed
handler.postDelayed(new Runnable() {Overridepublic void run() {Log.e(TAG, handler.postDelayed :);}
},DELAYTIME);
注意以上用法timer可以复用timerTask不可复用。
第二种和第三中都依赖Handler先定义一个handler
public static class MyHandler extends Handler{private final WeakReferenceActivity activityWeak;public MyHandler(Activity activity){activityWeak new WeakReference(activity);}Overridepublic void handleMessage(NonNull Message msg) {super.handleMessage(msg);TimerActivity activity (TimerActivity) activityWeak.get();switch (msg.what){case TimerActivity.MESSAGE1:Log.e(TAG, handleMessage: whatmsg.what );break;default:Log.e(TAG, handleMessage: default -whatmsg.what );break;}}
}
2、Handler.postDelayed
handler.postDelayed(new Runnable() {Overridepublic void run() {Log.e(TAG, handler.postDelayed :);}
},DELAYTIME);
3、Handler.sendEnptyMessageDelayeed
Log.e(TAG, handler.sendEmptyMessageAtTime :start);
handler.sendEmptyMessageDelayed(MESSAGE1,DELAYTIME);
Log.e(TAG, handler.sendEmptyMessageAtTime :);
4、Thread.sleep线程休眠-需要在子线程sleep是线程的方法他休眠中不会释放锁
Log.e(TAG, Thread.sleep: onClick );
Object lock new Object();
new Thread() {Overridepublic void run() {super.run();try {synchronized (lock){Log.e(TAG, Thread.sleep: 子线程start );Thread.sleep(20000);Log.e(TAG, Thread.sleep: 子线程end );}} catch (InterruptedException e) {e.printStackTrace();}}
}.start();
try {Log.e(TAG, Thread.sleep: onClick-1 );Thread.sleep(200);//此行代码影响甚大需灵活注释
虽然上面new Thread耗时很短但是也是有一定开销足以让它在主线程顺序之后执行Log.e(TAG, Thread.sleep: 主线程执行-准备获取锁 );synchronized (lock){Log.e(TAG, Thread.sleep: 主线程已获得锁 );}Log.e(TAG, Thread.sleep: 主线程已释放锁锁 );
} catch (InterruptedException e) {e.printStackTrace();
}
主线程没有200毫秒延时也就是注释Thread.sleep(200)就会先执行主线程然后进入子线程虽然上面new Thread耗时很短但是也是有一定开销足以让它在主线程顺序之后执行以上代码测试发现从new Thread到子线程内第一行代码执行耗时不足1毫秒。以下是运行日志2023-12-11 15:12:26.944 18617-18617/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: onClick2023-12-11 15:12:26.945 18617-18617/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: onClick-12023-12-11 15:12:26.945 18617-18617/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 主线程执行-准备获取锁2023-12-11 15:12:26.946 18617-18617/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 主线程已获得锁2023-12-11 15:12:26.946 18617-18919/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 子线程start2023-12-11 15:12:46.947 18617-18919/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 子线程end 主线程有200毫秒延时也就是不注释Thread.sleep(200)就会先进入子线程执行完
然后进入主线程。以下是运行日志2023-12-11 15:09:40.785 17990-17990/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: onClick 2023-12-11 15:09:40.786 17990-17990/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: onClick-1 2023-12-11 15:09:40.786 17990-18231/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 子线程start 2023-12-11 15:09:40.987 17990-17990/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 主线程执行-准备获取锁 2023-12-11 15:10:00.787 17990-18231/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 子线程end 2023-12-11 15:10:00.787 17990-17990/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.sleep: 主线程已获得锁
5、使用AlarmManager-全局定时器或者闹钟。适用一直在后台运行的定时任务此处放在一个service执行
Intent intent new Intent();
intent.setAction(short);
ComponentName component new ComponentName(TimerActivity.this, MyReceiver.class);
intent.setComponent(component);
//这里除了启动广播也可以换成启动Activity和service
PendingIntent sender PendingIntent.getBroadcast(TimerActivity.this,0,intent,0);Calendar calendar Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.add(Calendar.SECOND,5);
AlarmManager alarmManager (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP,System.currentTimeMillis(),sender);
6、Wait-必须使用synchronized他是Object的方法他休眠会释放锁 Object lock new Object();new Thread(){Overridepublic void run() {super.run();try {
// synchronized (lock){ //没有synchronized锁就会报错java.lang.IllegalMonitorStateException: object not locked by thread before wait()Log.e(TAG, Thread.wait: start );//以下两行需灵活注释lock.wait(2000);
// Thread.sleep(2000);Log.e(TAG, Thread.wait: end );
// }} catch (Exception e) {e.printStackTrace();}Log.e(TAG, Thread.wait: 子线程第二条 );}}.start();try {Thread.sleep(200);Log.e(TAG, Thread.wait: 主线程开始获取锁 );synchronized (lock){Log.e(TAG, Thread.wait: 主线程已获得锁 );}} catch (InterruptedException e) {e.printStackTrace();}
lock.wait(2000)放开Thread.sleep(2000)注释日志如下2023-12-11 14:21:34.371 9385-9748/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: start2023-12-11 14:21:34.571 9385-9385/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: 主线程开始获取锁2023-12-11 14:21:34.571 9385-9385/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: 主线程已获得锁2023-12-11 14:21:36.372 9385-9748/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: end2023-12-11 14:21:36.372 9385-9748/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: 子线程第二条 Thread.sleep(2000)放开lock.wait(2000)注释日志如下
sleep是线程的方法他休眠中不会释放锁2023-12-11 14:24:27.519 10346-10750/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: start2023-12-11 14:24:27.719 10346-10346/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: 主线程开始获取锁2023-12-11 14:24:29.520 10346-10750/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: end2023-12-11 14:24:29.520 10346-10750/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: 子线程第二条2023-12-11 14:24:29.520 10346-10346/com.example.testdemo3 E/com.example.testdemo3.activity.TimerActivity: Thread.wait: 主线程已获得锁
