Activity calls onCreate on Back

Question

I have an Activity called A and some event on Activity A calls Activity B. Now when I use the up-navigation in the Activity B, it comes back to Activity A but also calls the onCreate method. If I use the hardware/soft keys for the back, it does not call the onCreate and just comes back to Activity A where it was left. How do I make the up-navigation behave the same way?

My onCreate makes network calls asynchronously. Making another call just wastes data and time. This is the code I use to launch activity B from activity A.

Intent intent = new Intent(MainActivity.this, newsIndexActivity.class);
                    intent.putExtra("CityName", cityName.getText());
                    startActivity(intent);

don't fight with the system: your parent activity can be destroyed at any time so you need to be prepared that it is created from the scratch (onCreate being called) — pskink, Feb 10 '15 at 09:37
Fair enough. In that case, can I check if my activity is destroyed? If not destroyed, why create it again? — Samarth Agarwal, Feb 10 '15 at 09:47
But it is there if I use the back button, even after 5 minutes. — Samarth Agarwal, Feb 10 '15 at 10:04
so see what is done when back button is pressed: http://androidxref.com/4.4.4_r1/xref/frameworks/base/core/java/android/app/Activity.java#onBackPressed — pskink, Feb 10 '15 at 10:09

score 5 · Answer 1 · answered Feb 10 '15 at 09:14

Up and back navigation are not the same, if you want your Up navigation button to behave like back button you should do something like this

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            this.finish();
            return true; 
    }
    return super.onOptionsItemSelected(item);
}

If possible you should take a look to this link:

http://developer.android.com/design/patterns/navigation.html

There you can have more information about this.

Tried that. Still the same behaviour. – Samarth Agarwal Feb 10 '15 at 09:20 — Samarth Agarwal, Feb 10 '15 at 09:20

score 1 · Answer 2 · answered Feb 13 '20 at 15:45

1

By declaring parent activities’ launchMode as singleTop, we prevent the system from creating a new activity each time we press Up.

answered Feb 13 '20 at 15:45

Ajay Deepak

471
5
9

This worked for me. I added android:launchMode="singleTop" to the relevant activity in AndroidManifest.xml. – user2020792 Sep 12 '20 at 22:56

score 0 · Answer 3 · answered Feb 10 '15 at 08:58

0

Without any code seems difficult to resolve, but the most probably cause is that you are calling to startActivity. Just close your current activity using finish() and using the backstack it should behave as expected.

answered Feb 10 '15 at 08:58

zozelfelfo

3,776
2
21
35

Dhrumil Shah - dhuma1981 · Answer 4 · 2015-02-10T09:11:23.567

-3

Just call finish() or onBackPressed() method in your button callback listener.

finish();
super.onBackPressed();

edited Feb 10 '15 at 09:11

answered Feb 10 '15 at 08:57

Dhrumil Shah - dhuma1981

15,166
6
31
39

`supre.onBackPressed();`. you misspelled `super`. `super.onBackPressed();` calls already `finish()` – Blackbelt Feb 10 '15 at 09:10
I tried that. Didn't work. OnCreate is called everytime I use the UP Button. – Samarth Agarwal Feb 10 '15 at 09:32

Activity calls onCreate on Back

4 Answers4