CODEWITHSUNDEEP
androidandroid-handler
user1288005
user1288005

Reputation: 920

Create timer(Handler) when view appears and stop it when view disappears

I have been developing iOS apps for quite a time and now i have switched to android. I have a requirement in which I have to start timer(In think in Android, I need to use handler) when view appears(onResume) and invalidate timer(stop handler) when view disappears(onPause). I am able to create runnable Handler but not able to stop it. My code is:

     protected void AutoRefresh() {
     try{
handler.postDelayed(new Runnable() {
                     public void run() { 
                          new LongOperation().execute("");
                         }
                         AutoRefresh();

                 }, 60000);
    }
        catch(Exception ex){

        }

}

Now, how can I stop this this handler thread when view disappears. Please also comment, if its not the right way to do timer implementation in android.

Upvotes: 2

Views: 590

Answers (1)

user
user

Reputation: 87064

when view appears(onResume) and invalidate timer(stop handler) when view disappears(onPause). I am able to create runnable Handler but not able to stop it.

Keep a reference to the Runnable you use:

private Runnable mRefresh = new Runnable() {
     public void run() { 
          new LongOperation().execute("");
     }
     AutoRefresh();
}
//...
protected void AutoRefresh() {
    handler.postDelayed(mRefresh, 60000);
}

and in onPause remove it like this:

handler.removeCallbacks(mRefresh);

Keep in mind that this will not remove the currently Runnable that is being executed(if any) so in the LongOperation's onPostExecute method you might want to check if the Activity is still available before refreshing the UI or doing any other interaction with the Activity.

Please also comment, if its not the right way to do timer implementation in android.

You seem to need to do an action at a certain interval of time and using a Handler is the way to do it, I don't think a timer is what you need.

Upvotes: 2

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