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How to stop the Timer in android? [closed]

开发者 https://www.devze.com 2023-02-10 22:24 出处:网络
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I'm developing an application which sends a message to a specific number in a specific period of time. The problem is that it continues sending that 开发者_运维百科message after that period of time. How would I stop the timer after that specific time in order to stop sending that message?


     CountDownTimer waitTimer;
     waitTimer = new CountDownTimer(60000, 300) {

       public void onTick(long millisUntilFinished) {
          //called every 300 milliseconds, which could be used to
          //send messages or some other action
       }

       public void onFinish() {
          //After 60000 milliseconds (60 sec) finish current 
          //if you would like to execute something when time finishes          
       }
     }.start();

to stop the timer early:

     if(waitTimer != null) {
         waitTimer.cancel();
         waitTimer = null;
     }


and.. we must call "waitTimer.purge()" for the GC. If you don't use Timer anymore, "purge()" !! "purge()" removes all canceled tasks from the task queue.

if(waitTimer != null) {
   waitTimer.cancel();
   waitTimer.purge();
   waitTimer = null;
}


In java.util.timer one can use .cancel() to stop the timer and clear all pending tasks.


We can schedule the timer to do the work.After the end of the time we set the message won't send.

This is the code.

Timer timer=new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
    @Override
    public void run() {
            //here you can write the code for send the message
        }
    }, 10, 60000);

In here the method we are calling is,

public void scheduleAtFixedRate (TimerTask task, long delay, long period)

In here,

task : the task to schedule

delay: amount of time in milliseconds before first execution.

period: amount of time in milliseconds between subsequent executions.

For more information you can refer: Android Developer

You can stop the timer by calling,

timer.cancel();


I had a similar problem: every time I push a particular button, I create a new Timer.

my_timer = new Timer("MY_TIMER");
my_timer.schedule(new TimerTask() {
...
}

Exiting from that activity I deleted the timer:

if(my_timer!=null){
my_timer.cancel();
my_timer = null;
}

But it was not enough because the cancel() method only canceled the latest Timer. The older ones were ignored an didn't stop running. The purge() method was not useful for me. I solved the problem just checking the Timer instantiation:

if(my_timer == null){
my_timer = new Timer("MY_TIMER");
my_timer.schedule(new TimerTask() {
...
}
}


It says timer() is not available on android? You might find this article useful.

http://developer.android.com/resources/articles/timed-ui-updates.html


I was wrong. Timer() is available. It seems you either implement it the way it is one shot operation:

schedule(TimerTask task, Date when) // Schedule a task for single execution.

Or you cancel it after the first execution:

cancel()  // Cancels the Timer and all scheduled tasks.

http://developer.android.com/reference/java/util/Timer.html


I had a similar problem and it was caused by the placement of the Timer initialisation.

It was placed in a method that was invoked oftener.

Try this:

Timer waitTimer;

  void exampleMethod() {

   if (waitTimer == null ) {
    //initialize your Timer here
    ...
   }

The "cancel()" method only canceled the latest Timer. The older ones were ignored an didn't stop running.

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