Android: how to use OnCreate() when pressing backbutton

Question

When pressing the backbutton I want that, whatever screen will be loading, the onCreate() method will be executed. I want this because the screens must be refreshing when navigating through the app.

Do I need to override the back button method?

if(keyCode == KeyEvent.KEYCODE_BACK)
{

    }

Calling the OnCreate() when the back button is pressed sounds like really bad practice. Anyway you can still override the OnBackPressed method — Ika, May 02 '12 at 08:24

score 16 · Accepted Answer · edited Sep 17 '17 at 15:38

16

When you press the back button, the onResume() method is called, so instead of using onCreate(), use this and do whatever you need to do for refreshing the activity.

edited Sep 17 '17 at 15:38

lambda

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answered May 02 '12 at 08:24

Finuka

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That's the right answer. See http://developer.android.com/guide/topics/fundamentals/activities.html#Lifecycle – shkschneider May 02 '12 at 08:26
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To get to know the Activity lifecycle a bit better I also suggest that you display a toast everytime the different methods of an Activity are triggered.. so in onResume() you Toast.makeText(this, "onResume()", Toast.LENGTH_SHORT).show(); .. same in onStop() and onCreate(), onStart() etc :) – DecodeGnome May 02 '12 at 08:36

score 2 · Answer 2 · answered May 02 '12 at 08:26

You approach is wrong. onCreate() will only be called when the Activity is created. But everytime the Activity comes to the front the Method onResume will be called, this Method will also be called on the first start.
Look at the Activity Lifecycle for further info: http://fs01.androidpit.info/wiki/de/b/Beginners_Workshop_Activity_LC.png

score 1 · Answer 3 · answered May 02 '12 at 08:25

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When an activity is coming from background its onResume() method will be called. You should update your UI there.

answered May 02 '12 at 08:25

sachy

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score 0 · Answer 4 · answered May 02 '12 at 08:25

0

f you want execute anything after the back button you have to override it. Can you just refresh some part of the activity, not the whole one?

answered May 02 '12 at 08:25

goodm

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Android: how to use OnCreate() when pressing backbutton

4 Answers4