How to Stop Handler thread?

Question

I want to stop this thread on button click.

TIME_OUT = 45000;
new Handler().postDelayed(new Runnable() {
       @Override
       public void run() {
         Intent i = new 
         Intent(MapsActivity.this,MapsActivity.class);
         startActivity(i);
         finish();
       }
     }, TIME_OUT);

I am using above handler in onCreate of an Activity. I want to stop it. How to stop this thread on click of any button or on click of on Back Pressed?

score 6 · Answer 1 · answered Nov 04 '17 at 09:53

6

Handler handler = new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    Intent i = new 
                     Intent(MapsActivity.this,MapsActivity.class);
                    startActivity(i);
                    finish();
                }
            }, TIME_OUT);

Then you can use Handler#removeCallbacksAndMessages to remove this or any callback.

handler.removeCallbacksAndMessages(null);

answered Nov 04 '17 at 09:53

Alex Chengalan

8,211
4
42
56

where to use handler.removeCallbacksAndMessages(null); onStop() or onPause() or onBackPressed() – Ankesh Roy Nov 24 '17 at 11:56
you can remove it just before your `finish();` call – Alex Chengalan Nov 26 '17 at 12:48

score 3 · Answer 2 · answered Nov 04 '17 at 09:58

Okay the best option is to use a boolean as a flag like that

TIME_OUT = 45000;

//add this boolean
boolean run =true;

new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {

                //run this method only when run is true
                 if(run==true){

                    //your code
                   }

            }
        }, TIME_OUT);

             //on button click just change the boolean to flag and it will stop the run method
              //on click
              run=false;

where to use this comple mthod on activity please explain i am new in android. — Ankesh Roy, Nov 24 '17 at 11:58

score 2 · Answer 3 · edited Jan 04 '22 at 08:22

2

public class MainActivity extends Activity{
Handler handler;
Button b;

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       

handler = new Handler();
    Runnable runnable = new Runnable() {
        @Override
        public void run() {
            Intent i = new
                    Intent(MapsActivity.this,MapsActivity.class);
            startActivity(i);
           finish();
        }
    };
    handler.post(runnable);

button1=(Button)findViewById(R.id.button1);  
        button1.setOnClickListener(new OnClickListener() {  
            @Override  
            public void onClick(View arg0) {  
               handler.removeCallbacks(runnable);  
            }  
        });  

   
}


 
}

edited Jan 04 '22 at 08:22

Chandra Shekhar

3,550
2
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answered Nov 04 '17 at 11:05

Dilip

2,622
1
20
27

please try to explain your answer. – Ankesh Roy Nov 24 '17 at 09:12
while using handler on onCreate() method so i want to know where to stop it. – Ankesh Roy Nov 24 '17 at 11:59
1

On button click linstener we stop handler here. – Dilip Nov 24 '17 at 12:03
1

this should be like this handler.removeCallbacks(runnable); – Innocent Sep 18 '20 at 09:39

JiratPasuksmit · Accepted Answer · 2017-12-28T08:09:00.347

1

Handler handler = new Handler();
Runnable runnable = new Runnable() {
    @Override
    public void run() {
        Intent i = new
                Intent(MapsActivity.this,MapsActivity.class);
        startActivity(i);
        finish();
    }
};
handler.post(runnable);

// use this when you don't want callback to be called anymore
handler.removeCallbacks(runnable);

edited Dec 28 '17 at 08:09

answered Nov 04 '17 at 09:54

JiratPasuksmit

672
7
18

where to use handler.removeCallbacks(runnable) – Ankesh Roy Nov 24 '17 at 11:56
@AnkeshRoy when you not need callback to be called. For example, when you start handler thread and user already end the activity and you dont want handler’s callback to run, so you removeCallbacks() in onDestroy(). – JiratPasuksmit Nov 24 '17 at 11:57
app is getting crashed when apply on onDestroy(); – Ankesh Roy Nov 24 '17 at 12:03
what is the error log? – JiratPasuksmit Nov 24 '17 at 12:04
handler.removeCallbacksAndMessages(null); indicating error at this line with Cannot instantiate the type Runnable when i am removing it working well but my app is not getting closed . – Ankesh Roy Nov 24 '17 at 12:05
please check that your runnable is not null first, make sure it is initialized before you call that statement. – JiratPasuksmit Nov 24 '17 at 12:06

How to Stop Handler thread?

4 Answers4