NullPointerException onDestory

Question

When the app starts and I try to immediately rotate the screen It gives me this error:

public void onDestroy() {
        super.onDestroy();
        appbars.animate().translationY(0).alpha(1).setDuration(100).setInterpolator(new DecelerateInterpolator());

    }

Error:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.ViewPropertyAnimator
 android.support.design.widget.AppBarLayout.animate()' on a null object
 reference

AppBarLayout might not be initialized (findViewById) – Hemanth S Dec 29 '17 at 06:42 — Hemanth S, Dec 29 '17 at 06:42

Goku · Accepted Answer · 2017-12-29T06:58:23.053

1

Try this check your appbars is null or not like this

 public void onDestroy() {
     super.onDestroy();
       if(appbars!=null) {
       appbars.animate().translationY(0).alpha(1).setDuration(100).setInterpolator(new DecelerateInterpolator());
    }

edited Dec 29 '17 at 06:58

answered Dec 29 '17 at 06:37

Goku

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may i know the reason for downvote – Goku Dec 29 '17 at 07:08

score 1 · Answer 2 · edited Dec 29 '17 at 06:43

1

public void onDestroy() {
        super.onDestroy();
       if(appbars!=null){  // use this 
     appbars.animate().translationY(0).alpha(1).setDuration(100).setInterpolator(new DecelerateInterpolator());   

    }

edited Dec 29 '17 at 06:43

Goku

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answered Dec 29 '17 at 06:39

oj24031989

31
1
4

Leonid Veremchuk · Answer 3 · 2017-12-29T06:44:35.400

1

Your appbars was destroyed and no more exist. Also you need to move stop work in onPause() for better performance.

Activity lifecycle :

edited Dec 29 '17 at 06:44

answered Dec 29 '17 at 06:39

Leonid Veremchuk

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As fellow members suggested: problem was `onDestroy` triggered before the `AppBarLayout` loaded thus I got the null pointer error – Fresco Dec 29 '17 at 06:58
I was tell you about bad practice in your code. If you want to get answer how avoid this you had to many examples below. GL and HF – Leonid Veremchuk Dec 29 '17 at 07:13
If i don't use `onDestory` I have to implement this code in other tabs as well. Thanks for your suggestion – Fresco Dec 29 '17 at 07:29

score 1 · Answer 4 · answered Dec 29 '17 at 06:39

1

try with this..

public void onDestroy() {
    super.onDestroy();
    if(appbars!=null) {
       appbars.animate().translationY(0).alpha(1).setDuration(100).setInterpolator(new DecelerateInterpolator());
    }
}

Hope this helps..

answered Dec 29 '17 at 06:39

Nikhil Borad

2,055
15
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NullPointerException onDestory

4 Answers4