overriding back method in fragment class in android

Question

how to quit the app whenever i press the back button from certain fragments.I found out that system.exit(1) closes the app. but i could now override method for handling back key.Is there any method to override back key ? if yes How can i perform it?

No, but what can you do is overRide onBack in activity and, make condition accordingly — Abdul Kawee, May 29 '17 at 06:05
actually i have about 7 fragments all under 1 activity and i only need to quit app from 1 fragment class.. — Yogesh, May 29 '17 at 06:10
i am using master/detail flow which has 1 activity. and i am using fragment transaction for managing layouts and handling other activities. — Yogesh, May 29 '17 at 06:15
AddFriends fragment=new AddFriends(); android.support.v4.app.FragmentTransaction fragmentTransaction=getSupportFragmentManager().beginTransaction(); fragmentTransaction =getSupportFragmentManager().beginTransaction(); fragmentTransaction.replace(R.id.fragment_container,fragment).addToBackStack("c"); fragmentTransaction.commit(); — Yogesh, May 29 '17 at 06:17
Try removing addToBackStack('c') and check what is the result? — AbhayBohra, May 29 '17 at 06:18

score 0 · Answer 1 · answered May 29 '17 at 06:05

0

onBackPressed() function in activity will help

answered May 29 '17 at 06:05

Jithin.S

47
1
8

this should be in comments – Abdul Kawee May 29 '17 at 06:05
i cannnot able to comment – Jithin.S May 29 '17 at 06:06
thanks for your answer but i have only one activity and about 7 fragments and i only need to quit from 1 fragments... – Yogesh May 29 '17 at 06:07
https://stackoverflow.com/questions/5448653/how-to-implement-onbackpressed-in-fragments this answer will be helpful – Jithin.S May 29 '17 at 06:14

Abdul Kawee · Answer 2 · 2017-05-29T06:52:22.290

0

What you should do, is when you add a fragment add a tag with it, like

fragmentTransaction.replace(android.R.id.content, fragment, "My_Tag");

And then in activity onBackPressed()

fragment= (AddFriends)getFragmentManager().findFragmentByTag("My_Tag");
if (fragment!= null && fragment.isVisible()) {
   //Exit from your app here
   finish();
}

Hope this helps you.

edited May 29 '17 at 06:52

answered May 29 '17 at 06:24

Abdul Kawee

2,687
1
14
26

thanks for your answer. but i got an error on back pressed in line 1 showing inconvertible type. i had assummed that MyFragment in above code means the fragment that should be override on back press... – Yogesh May 29 '17 at 06:45
@YogeshGautam I dont know about your code but what you shared in comments from that i suggest changing `MyFragment` with your fragment – Abdul Kawee May 29 '17 at 06:50

score 0 · Answer 3 · answered May 29 '17 at 06:41

write this in your onBackPressed()

if (fragmentManager.getBackStackEntryCount() == 1) {
        if (isPressed) {
            finish();
        } else {
            StringUtils.displayToastShort(this, "press again to exit");
            isPressed = true;
        }
}

score 0 · Answer 4 · answered May 29 '17 at 06:53

Try this function for opening a fragment

public void openFragment(Fragment fragment)
{

FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransac‌tion();

fragmentTransaction.replace(R.id.fragment_container,fragment);

fragmentTransaction.commit();

}

and when you want to open a fragment call this function like this

openFragment(new AddFriends());

Using above function it will exit the app with back button press.

Yogesh · Accepted Answer · 2017-07-19T17:18:30.993

0

I solved it in following way.

First make a class with static integer variable(say a).
Override back methods on mainActivity and choose the fragment you want to open on back pressed as per the value on static variable. [note:whenever new fragments are opened update static variable with new value and according to this value override back method on main activity]

edited Jul 19 '17 at 17:18

answered Jul 19 '17 at 17:01

Yogesh

153
1
12

overriding back method in fragment class in android

5 Answers5