does not close android app by pressing back button

Question

Possible Duplicate:
android pressing back button should exit the app

I am trying to close an app using mobile's back button. Currently I am overriding onKeyPressed method and calling moveTaskToBack(true);. It does hides the app but does not close it. It still remains in the memory. How can I close the app by pressing the back button?

Here is my code

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        moveTaskToBack(true);
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

This is correct behaviour. Why do you want to close your app? In nearly every situation, you should let Android handle memory management and app closing. — Simon, Oct 02 '12 at 07:10
http://stackoverflow.com/questions/2033914/quitting-an-application-is-that-frowned-upon — Nermeen, Oct 02 '12 at 07:12

score 2 · Accepted Answer · edited May 23 '17 at 12:06

2

I think its safer to do this.finish(); instead.

System.exit(0) is not recommended, better let Android do the management of the app.

Check this link : Is quitting an application frowned upon?

edited May 23 '17 at 12:06

Community

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answered Oct 02 '12 at 07:12

midhunhk

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score 2 · Answer 2 · edited May 23 '17 at 10:27

You don't. Well, not completely.

An app's lifecycle is made in such a way that being in the background is normal and expected. This allows apps to be quickly restored to the front if/when the user wants, and allows Android to do the memory management. You have special methods like onPause() and onResume() to help you handle this.

Beyond that, finish() will close the current activity and remove it from the stack, while System.exit(0) should close the app.

You should read an excellent answer by CommonsWare (Mark Murphy) to this question, as it addresses a number of reasons to let Android keep your app in the memory.

score 1 · Answer 3 · answered Oct 02 '12 at 07:11

1

When you push the new activity, call finish() on the previous, otherwise it will remain on the stack, therefore appearing when you hit back and pop the current activity.

answered Oct 02 '12 at 07:11

Ram kiran Pachigolla

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score 1 · Answer 4 · answered Oct 02 '12 at 07:17

You should be able to use finish() to close down your app. However if it's due to memory management, I'd rather use android's own memory management. It's actually quite good. It will periodically remove applications which are paused, if it's necessary to free up memory. And unless it's a service, it shouldn't take up too much memory while lying in the stack. There are exceptions however.

score 1 · Answer 5 · answered Oct 02 '12 at 07:36

1

Don't hold it to me but I believe onbackpressed is now the recommended method. And yes finish () ; should work just fine.

answered Oct 02 '12 at 07:36

mango

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Kumar Vivek Mitra · Answer 6 · 2012-10-02T07:17:20.570

0

- Use System.exit(0) to close you app at the back button, this is quite useful with java application, same works for Android, but then it would be advisable to use the below methods.

finish() and finishActivity() are 2 alternatives

edited Oct 02 '12 at 07:17

answered Oct 02 '12 at 07:10

Kumar Vivek Mitra

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score 0 · Answer 7 · edited May 23 '17 at 12:06

0

If you want to exit application, write following:

finish()

because System.exit(0) is not recommended. This will also exit from your application.

edited May 23 '17 at 12:06

Community

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answered Oct 02 '12 at 07:10

Hardik Joshi

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I use System.exit(0); to exit from my application. @DineshVenkata You have any solution for that? and Y you give negative point? its working. – Hardik Joshi Oct 02 '12 at 07:14
2

have a look at the documents its never advised to use System.exit(0) as it is not a part of the lifecycle of an activity – Dinesh Venkata Oct 02 '12 at 07:16
Because you should always be a good Android citizen. Android works much better (and faster) when it can manage memory and loading/unloading apps itself. It is very rare that System.exit() is needed, it is bad practice and just because you can do does not mean you should. – Simon Oct 02 '12 at 07:16
Infact he down voted my comment @simon – Dinesh Venkata Oct 02 '12 at 07:17
Sorry, my comment is for Hardik. – Simon Oct 02 '12 at 07:18
@Simon i edit my answer thanks for giving such a knowledge. – Hardik Joshi Oct 02 '12 at 07:19
@Simon I understand what I meant was he was not comfortable with the down vote for his answer. – Dinesh Venkata Oct 02 '12 at 07:19
@hardikjoshi what happend why did you change your mind? – Dinesh Venkata Oct 02 '12 at 07:20
@DineshVenkata i not know perfectly about System.exit(0) so that i edit it. Now onwards i never use it and find alternative for it. – Hardik Joshi Oct 02 '12 at 07:22
good but you shouldn't have down voted my comment without realizing what you did. – Dinesh Venkata Oct 02 '12 at 07:23
@DineshVenkata sorry for that. – Hardik Joshi Oct 02 '12 at 07:26

score -1 · Answer 8 · answered Oct 02 '12 at 07:10

-1

System.exit(0) closes the entire app. finish() is another snippet that closes the current activity.

answered Oct 02 '12 at 07:10

MrYanDao

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does not close android app by pressing back button

8 Answers8