Four ways of implementing timer in Android and its implementation example _android

Four ways to implement timers in Android

The first way to make use of timer and TimerTask

1. Inheritance Relationship

Java.util.Timer

Basic methods

Schedule

For example:

Timer.schedule (task, delay,period);  
Delay is long,period long: Once delay milliseconds from now on, it is performed every period milliseconds.  

The schedule method has three parameters

The first parameter is the object of the TimerTask type, and our implementation of the TimerTask run () method is a task to be performed periodically;

The second parameter has two types, the first is a long type, indicating how long it starts and the other is the date type, which indicates that execution begins after that time;

The third parameter is the period of execution, which is a long type.

2,

TimerTask task= New TimerTask () { 
     @Override public 
     void Run () { 
        count++; 
        LOG.I ("Mainactivity", Count + ""); 
     } 
}; 

Here are several ways to schedule tasks:

Time is a date type: Executes once at a specified period.  
Timer.schedule (task, time);  
Firsttime is a date type and period is long, which is executed every period millisecond from firsttime time.  
timer.schedule (task, firsttime,period);    
Delay is long: delay milliseconds from now to execute once.  
timer.schedule (task, delay);   
Delay is long,period long: Once delay milliseconds from now on, it is performed every period milliseconds.  
timer.schedule (task, delay,period);  

Note: The task should be canceled in Ondestory (), or a crash may occur

3, with timertask timing of some operation of the app, even if the exit, TimerTask will still run for a while, but can not run for a long time

The second way of using Countdowntimer

1, Demo

Countdowntimer CDT = new Countdowntimer (10000) {@Override public 
  void Ontick (long millisuntilfinished) { 
    Tv_hello.settext (millisuntilfinished + ""); 
  } 
  @Override public 
  void OnFinish () { 
     
  } 
}; 
 
Cdt.start (); 

2, the above example is

Execute the Ontick method once every 100 milliseconds
The method in OnFinish () will be executed until the end of the 10000/100-time execution.

The Third Way of Alarmmanager

Demo

Intent Intent2 = newintent (readlogservice.this,testbroadcast.class); 
Pendingintent PD =pendingintent.getbroadcast (getapplicationcontext (), 0, intent2,pendingintent.flag_one_shot); 
Alarmmanager am = (alarmmanager) getsystemservice (alarm_service); 
Long Triggertime =systemclock.elapsedrealtime () + 5*1000; 
Am.set (Alarmmanager.elapsed_realtime,triggertime, PD); 

The fourth way of Alarmmanager

handler.sendemptymessagedelayed (0, 4000);//Start Handler, implement 4 seconds timed loop execution 
Private Handler handler = new Handler () { 
Public voidhandlemessage (Android.os.Message msg) { 
           
      if (ischange) { 
          //logical processing 
       
            Handler.sendemptymessagedelayed (0,4000);//4 seconds after execution 
      }} 
; 

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