Android: NullPointerException at getActionBar

Question

I'm implementing navigation drawer sliding menu .getting java.lang.NullPointerException at the

getActionBar().setDisplayShowHomeEnabled(true);
getActionBar().setHomeButtonEnabled(true);

In my Application I have tried activity extended Activity and also AppCompatActivity.

Here is my onCreate code

protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mTitle = mDrawerTitle = getTitle();

        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);
        navMenuIcons = getResources().obtainTypedArray(R.array.nav_drawer_icons);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.list_slidermenu);
        navDrawerItems = new ArrayList<NavDrawerItem>();
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1)));
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1)));
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1), true, "22"));
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[4], navMenuIcons.getResourceId(4, -1)));
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[5], navMenuIcons.getResourceId(5, -1), true, "50+"));
        navMenuIcons.recycle();
        mDrawerList.setOnItemClickListener(new SlideMenuClickListener());
        adapter = new NavDrawerListAdapter(getApplicationContext(), navDrawerItems);
        mDrawerList.setAdapter(adapter);
       //abling action bar app icon and behaving it as toggle button
        getActionBar().setDisplayShowHomeEnabled(true);
        getActionBar().setHomeButtonEnabled(true);
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,

                R.drawable.menu_left, //nav menu toggle icon
                R.string.app_name, // nav drawer open - description for accessibility
                R.string.app_name // nav drawer close - description for accessibility
        )
        {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                // calling onPrepareOptionsMenu() to show action bar icons
                invalidateOptionsMenu();
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                // calling onPrepareOptionsMenu() to hide action bar icons
                invalidateOptionsMenu();}
        };

        mDrawerLayout.setDrawerListener(mDrawerToggle);
        if (savedInstanceState == null) {
            // on first time display view for first nav item
            displayView(0);
        }
    }

Here is LogCat inforamtion

 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.tazeen.slidingmenu/com.example.tazeen.slidingmenu.MainActivity}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.example.tazeen.slidingmenu.MainActivity.onCreate(MainActivity.java:62)
            at android.app.Activity.performCreate(Activity.java:5008)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)

possible duplicate of [getActionBar() returns null](http://stackoverflow.com/questions/6867076/getactionbar-returns-null) — Nir Alfasi, Sep 07 '15 at 04:37

diyoda_ · Answer 1 · 2015-09-07T04:55:35.320

If you are extending from AppCompatActivity you should use, getSupportActionBar()

If you are extending form Activity, You can use getActionBar(),

But in both the cases,

You have make sure to have a ActionBar supported theme assigned for your Activity.

Eg: Theme.AppCompat.Light

or you can programatically do it,

requestWindowFeature(Window.FEATURE_ACTION_BAR);

before

super.onCreate(savedInstanceState);

But it is best to have a style declared and assigned for your activity rather than doing it programatically.

score 0 · Answer 2 · answered Sep 07 '15 at 04:50

extends simple Activity instead of ActionBarActivity.and please always check null before setDisplayShowHomeEnabled() like:

if(getActionBar()!=null){
    getActionBar().setDisplayShowHomeEnabled(true);
        getActionBar().setHomeButtonEnabled(true);
    }

and another solution is to use getSupportActionBar() instead of getActionBar() and then

if(getSupportActionBar()!=null){
    getSupportActionBar().setDisplayShowHomeEnabled(true);
        getgetSupportActionBarActionBar().setHomeButtonEnabled(true);
    }

enjoy your code:)

Android: NullPointerException at getActionBar

2 Answers2