NullpointerException at actionbar in android

Question

I am newbie to android and working on a demo for swipe tabs demo and refering a link,Going step by step,but i stuck at a point,when i run the app,it throws nullpointerexception,Please see below code and help me to figure out please,

main_listing.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

java

public class MainListingActivity extends FragmentActivity {
    ViewPager Tab;
    TabPagerAdapter TabAdapter;
    ActionBar actionBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_listing);

        TabAdapter = new TabPagerAdapter(getSupportFragmentManager());

        Tab = (ViewPager)findViewById(R.id.pager);
        Tab.setOnPageChangeListener(
                new ViewPager.SimpleOnPageChangeListener() {
                    @Override
                    public void onPageSelected(int position) {

                        actionBar = getActionBar();
                        actionBar.setSelectedNavigationItem(position);                    }
                });
        Tab.setAdapter(TabAdapter);

        actionBar = getActionBar();
        //Enable Tabs on Action Bar
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        ActionBar.TabListener tabListener = new ActionBar.TabListener(){

            @Override
            public void onTabReselected(android.app.ActionBar.Tab tab,
                                        FragmentTransaction ft) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {

                Tab.setCurrentItem(tab.getPosition());
            }

            @Override
            public void onTabUnselected(android.app.ActionBar.Tab tab,
                                        FragmentTransaction ft) {
                // TODO Auto-generated method stub

            }};
        //Add New Tab
        actionBar.addTab(actionBar.newTab().setText("Android").setTabListener(tabListener));
        actionBar.addTab(actionBar.newTab().setText("iOS").setTabListener(tabListener));
        actionBar.addTab(actionBar.newTab().setText("Windows").setTabListener(tabListener));

    }

logcat

    FATAL EXCEPTION: main
Process: abc.kayraas.com.allaboutcity, PID: 15728
java.lang.RuntimeException: Unable to start activity ComponentInfo{abc.kayraas.com.allaboutcity/abc.kayraas.com.allaboutcity.MainListingActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2404)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2464)
    at android.app.ActivityThread.access$900(ActivityThread.java:172)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:146)
    at android.app.ActivityThread.main(ActivityThread.java:5653)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
    at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
    at abc.kayraas.com.allaboutcity.MainListingActivity.onCreate(MainListingActivity.java:37)
    at android.app.Activity.performCreate(Activity.java:5541)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2368)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2464) 
    at android.app.ActivityThread.access$900(ActivityThread.java:172) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1308) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:146) 
    at android.app.ActivityThread.main(ActivityThread.java:5653) 
    at java.lang.reflect.Method.invokeNative(Native Method)

style.xml

<resources>


    <style name="MyRadioButtonStyle" parent="@android:style/Widget.CompoundButton.RadioButton">
        <item name="android:button">@drawable/radio_selected</item>
    </style>

    <style name="AppBaseTheme" parent="android:Theme.Light">

    </style>

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->

        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>
</resources>

manifest

<application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".SlashActivity"
            android:theme="@android:style/Theme.Holo.Light.DarkActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

what kind of theme you are using in manifest. Action bar is deprecated. If then also you want to use theme that support action bar then use getSupportActionBar() method. — Abhishek, Dec 26 '16 at 09:46
Take a look at this question https://stackoverflow.com/questions/15206447/android-actionbar-nullpointerexception?rq=1 — Bhaskar Kandiyal, Dec 26 '16 at 09:49
@Abhishek - I have posted my manifest and style.can u help me? — concentrate H2SO4, Dec 26 '16 at 09:50
@JigarMakwana The layout you posted is titled **main_listing.xml** but your activity is using **activity_listing.xml**. Is this a mistake? — X09, Dec 26 '16 at 09:58
Here's the solution --> https://stackoverflow.com/a/59687573/8168140 — gsm, Jan 10 '20 at 19:09

score 0 · Accepted Answer · answered Dec 26 '16 at 09:43

0

try this :

actionBar=getSupportActionBar

answered Dec 26 '16 at 09:43

Ravish Sharma

207
2
14

when i am using getSupportActionBar,It gives error.(make getter method). – concentrate H2SO4 Dec 26 '16 at 09:50
please check this link:http://www.androidhive.info/2015/09/android-material-design-working-with-tabs/ – Ravish Sharma Dec 26 '16 at 09:52
uska hi refrence liya he bhai..!!! – concentrate H2SO4 Dec 26 '16 at 09:55
bhai me teko code de deta hu fir working ? – Ravish Sharma Dec 26 '16 at 10:08
na yar...sab try krk dekh lia..:(...pls help me – concentrate H2SO4 Dec 26 '16 at 10:10
are bhai pura code de ra hu teko me v isi pe kam kar ra hu email de apni me bhej deta hu – Ravish Sharma Dec 26 '16 at 10:11
wese v jis pe tu kam kar ra hai almost depricate hai ye action bar – Ravish Sharma Dec 26 '16 at 10:12
to kya kru?meko swipable tabs chaiye,or androidhive ka demo download krk copy kia but nullpointer aa rha hew – concentrate H2SO4 Dec 26 '16 at 10:14
o dost to email de latest code bhejta hu pura zip file me bnake tu direct import kar or run kar – Ravish Sharma Dec 26 '16 at 10:16
Ravish - Ho gya bhai..:) (Y) o thanks yara..:) – concentrate H2SO4 Dec 26 '16 at 10:25
wlcm dude kya galti thi ? – Ravish Sharma Dec 26 '16 at 10:37
theme me bhai,but ab ek or help chaiye,ye actionbar ka color change krna he?kese krte he – concentrate H2SO4 Dec 26 '16 at 10:39
http://stackoverflow.com/questions/30010744/android-how-to-change-my-action-bar-background-color ye answer dekh – Ravish Sharma Dec 26 '16 at 10:41
Here's the solution --> https://stackoverflow.com/a/59687573/8168140 – gsm Jan 10 '20 at 19:09

Rushi Ayyappa · Answer 2 · 2016-12-26T10:05:07.453

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setTitle("Home");

//in styles.xml in your AppTheme ,update as

 <style name="AppTheme" parent="Theme.AppCompat.NoActionBar">

//in your xml write this at the top :

  <android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:visibility="gone"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:visibility="visible"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

</android.support.design.widget.AppBarLayout>

this is your current code:

  <style name="AppTheme" parent="AppBaseTheme">
    <!-- All customizations that are NOT specific to a particular API-level can go here. -->

    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

instead write this:

 <style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

couldn't find "toolbar" – concentrate H2SO4 Dec 26 '16 at 09:51 — concentrate H2SO4, Dec 26 '16 at 09:51
you have to create a Toolbar in your xml. – Rushi Ayyappa Dec 26 '16 at 09:52 — Rushi Ayyappa, Dec 26 '16 at 09:52
Rushi-can u help me?how to do it – concentrate H2SO4 Dec 26 '16 at 09:55 — concentrate H2SO4, Dec 26 '16 at 09:55
It says canot resolve in theme.:( and also when i set – concentrate H2SO4 Dec 26 '16 at 09:59 — concentrate H2SO4, Dec 26 '16 at 09:59
Paste your app **build.gradle** also. – X09 Dec 26 '16 at 10:03 — X09, Dec 26 '16 at 10:03

score 0 · Answer 3 · answered Dec 26 '16 at 10:01

0

try this code. ActionBar actionBar = getSupportActionBar();

answered Dec 26 '16 at 10:01

xbadal

1,284
2
11
24

score 0 · Answer 4 · answered Dec 26 '16 at 10:20

0

In your style.xml change this line:

<style name="AppBaseTheme" parent="android:Theme.Light">

to

<style name="AppBaseTheme" parent="android:Theme.Holo.Light.DarkActionBar">

answered Dec 26 '16 at 10:20

Bhaskar Kandiyal

978
1
10
20

NullpointerException at actionbar in android

4 Answers4