ActionBar didn't work?

Question

My application crashes and I get

Error :

setNavigationMode(int)' on a null object reference

Code :

package com.example.muhammad_adel.tabs;


import android.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
    ActionBar actionBar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        actionBar.addTab(actionBar.newTab().setText("one"));
        actionBar.addTab(actionBar.newTab().setText("two"));
        actionBar.addTab(actionBar.newTab().setText("three"));
    }
}

change getActionBar() to getSupportActionBar(); and check it. — Rujul Gandhi, Dec 05 '16 at 06:47
http://stackoverflow.com/questions/30625128/java-lang-nullpointerexception-attempt-to-invoke-virtual-method-actionbar-setn — IntelliJ Amiya, Dec 05 '16 at 06:53
@IntelliJAmiya it's Already parent="Theme.AppCompat.Light.DarkActionBar" — Muhammad ADel, Dec 05 '16 at 06:59

Harshad Pansuriya · Answer 1 · 2016-12-05T07:01:17.000

2

Change 1 : instead of import android.support.v4.app.ActionBar use import android.support.v7.app.ActionBar in your activity

Change 2 : change this actionBar = getActionBar(); to actionbar = getSupportActionBar();

Update:

You have to use PagerSlidingTabStrip because setNavigationMode is now deprecated.

edited Dec 05 '16 at 07:01

answered Dec 05 '16 at 06:49

Harshad Pansuriya

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i get this exception java.lang.IllegalStateException: Action Bar Tab must have a Callback – Muhammad ADel Dec 05 '16 at 06:55
http://stackoverflow.com/questions/27726759/actionbar-setnavigationmodeactionbar-navigation-mode-tabs-deprecated – IntelliJ Amiya Dec 05 '16 at 07:12

score 1 · Answer 2 · edited May 23 '17 at 12:30

1

It's been long time since ActionBar got deprecated.

Try to use Toolbar and SlidingTabs.

Please refer to this answer for same question. It will provide you enough guide for your query.

Android, Tabs without Actionbar

You can easily implement this and it will be easy for you to handle onClick() events for tabs.

edited May 23 '17 at 12:30

Community

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answered Dec 05 '16 at 07:09

Pragnesh Ghoda シ

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Muhammad ADel · Accepted Answer · 2016-12-05T07:12:58.037

0

I find the solution thanks for your help

First instead of import android.app.ActionBar => import android.support.v7.app.ActionBar

Second changing this actionBar = getActionBar(); to actionbar = getSupportActionBar();

Third you must implement TabListener

edited Dec 05 '16 at 07:12

answered Dec 05 '16 at 07:07

Muhammad ADel

67
5

score 0 · Answer 4 · answered Dec 05 '16 at 09:05

0

You should Try to change your parent style

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

answered Dec 05 '16 at 09:05

Learning Always

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ActionBar didn't work?

4 Answers4