getActionBar returns null

Question

I m having an odd problem  I am making an app with targetsdk 13    In my main activity s onCreate method i call getActionBar   to setup my actionbar  This works fine when running on the Android 3 2 emulator  but when using Android 3 0 and 3 1 the getActionBar   method returns null   I find this extremely odd  and i cannot see any reason why it would do so  Is this a bug with the emulators or is there something i need to do  in order to ensure that my application has an actionbar    SOLUTION  I think I ve found a solution for this problem  I wasn t using the setContentView to set a layout for the activity  Instead I was using fragmentTransaction add android R id content  mFragment  mTag  to add a fragment to the activity  This worked fine in 3 2  but in earlier honeycomb versions the action bar is apparently not set if you don t use the setContentView in the onCreate   method  So I fixed it by using the setContentView   method in my onCreate   method and just supplying it with a layout that contained an empty FrameLayout  I can still use the fragmentTransaction add android R id content  mFragment  mTag  method the same way as before   It s not the prettiest fix  but it works

User · Answer

I had the same problem and one of the solutions was to use setContentView() before calling getActionBar().

But there was another thing that fixed the problem. I specified theme for the application to be @android:style/Theme.Holo.Light.

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.Holo.Light" >
    ...
</application>

I think any theme, which has <item name="android:windowActionBar">true</item> in it, can be used.

User · Answer

Just check the implementation of source code by command click       private void initWindowDecorActionBar         Window window   getWindow            Initializing the window decor can change window feature flags         Make sure that we have the correct set before performing the test below      window getDecorView         if  isChild       window hasFeature Window FEATURE ACTION BAR     mActionBar    null            return             mActionBar   new WindowDecorActionBar this       mActionBar setDefaultDisplayHomeAsUpEnabled mEnableDefaultActionBarUp        mWindow setDefaultIcon mActivityInfo getIconResource         mWindow setDefaultLogo mActivityInfo getLogoResource         requestWindowFeature Window FEATURE ACTION BAR   Fixed my issue as I saw         requestWindowFeature Window FEATURE ACTION BAR  is failing  code is open source use it

User · Answer

Try extending your Activity class from ActionBarActivity   This solved it for me   Do something like the following   public class MyActivity extends ActionBarActivity             In my case the class was extending only from Activity

User · Answer

In my case I simply had to extend AppCompatActivity instead of Activity      supportActionBar  setDisplayHomeAsUpEnabled true    Full activity example class   import android os Bundle import androidx appcompat app AppCompatActivity    class LocationFound   Activity      lt -----Does not seem to work with ActionBar in recent versions class LocationFound   AppCompatActivity          override fun onCreate savedInstanceState  Bundle             super onCreate savedInstanceState          setContentView R layout activity location found           supportActionBar  setDisplayHomeAsUpEnabled true            On Versions      minSdkVersion 22     targetSdkVersion 29

User · Answer

import android support v7 app AppCompatActivity    then  extends AppCompatActivity   then use  getSupportActionBar   setDisplayHomeAsUpEnabled true

User · Answer

Use getSupportActionBar   instead of getActionBar

User · Answer

I faced the above issue where getActionBar   method returns null  I was calling the getActionBar   after setting the setContentView   and still its returning a null   I resolved the issue by setting the min-sdk version in Android Manifest file that was missing initially   lt uses-sdk android minSdkVersion  11    gt

User · Answer

One thing I wanted to add since I just ran into this  if you are trying to getActionBar   on an Activity that has a parent  it will return null   I am trying to refactor code where my Activity is contained inside an ActivityGroup  and it took a good few minutes for me to go  oh duh  after looking at the source of how an ActionBar gets created in source

User · Answer

If you are using the support library  import android support v7 app ActionBarActivity   public class MainActivity extends ActionBarActivity     use getSupportActionBar   instead of getActionBar      Update   The class ActionBarActivity now is deprecated   import android support v7 app ActionBarActivity    I recommend to use   import android support v7 app AppCompatActivity

User · Answer

This may also help some people   In my case  it was because I had not defined a context in the menu xml  Try this     lt menu xmlns android  http   schemas android com apk res android  xmlns app  http   schemas android com apk res-auto  xmlns tools  http   schemas android com tools  tools context  com example android ActionBarActivity  gt    Instead of this    lt menu xmlns android  http   schemas android com apk res android  gt

User · Answer

Can use getSupportActionBar   instead of getActionBar   method

User · Answer

go to the AndroidManifest xml and replace  android theme   style AppTheme   by    android theme   android style Theme Holo Light DarkActionBar

User · Answer

To add to the other answers   Make sure you call setActionBar   or setSupportActionBar   in your onCreate   method before calling the getActionBar     Define some Toolbar in your activity xml  then in the onCreate     Toolbar toolbar    Toolbar  findViewById R id my toolbar   setSupportActionBar toolbar      Now you can use the get methods  getSupportActionBar   setDisplayHomeAsUpEnabled true

User · Answer

I ran into this problem   I was checking for version number and enabling the action bar only if it is greater or equal to Honeycomb   but it was returning null  I found the reason   and root cause was that I had disabled the Holo Theme style in style xml under values-v11 folder

User · Answer

In my case  I had this in my code which did not work    Override protected void onCreate Bundle savedInstanceState        context   getApplicationContext         requestWindowFeature Window FEATURE ACTION BAR        super onCreate savedInstanceState        setContentView R layout activity main       Then I played with the order of the code    Override protected void onCreate Bundle savedInstanceState        requestWindowFeature Window FEATURE ACTION BAR        super onCreate savedInstanceState        setContentView R layout activity main        context   getApplicationContext        And it worked   Conclusion  requestWindowFeature should be the first thing you call in the onCreate method

User · Answer

The main reason for that is using themes that are not supporting ActionBar   In manifest file add the following either in your target activity or application element  if you want to unify the theme over whole application   Examples of themes that are supporting action bar   Theme AppCompat Light  or  Theme Holo Light       android theme   android style Theme Holo Light    It is better to put all styles in styles xml and use it everywhere using   style themName  so the previous one will be   android theme   style AppTheme    and styles xml will have the following     lt style name  AppTheme  parent  Theme AppCompat Light  gt    Hints     There is some themes that can not be used in old SDKs like   android style Theme Holo Light DarkActionBar  is not supported before SDKs version 14  To allow your app to support minimum specific version of SDK you could add the following under  lt app gt  element    lt uses-sdk android minSdkVersion  14    gt   To specify min SDK version in AndroidStudio  you could by using app s Gradle file   android    defaultConfig      minSdkVersion 14     targetSdkVersion 21

User · Answer

android support v7 app ActionBar actionBar   getSupportActionBar      works pretty quickly

User · Answer

You have to define window type as actionbar before activity render its view   use   requestWindowFeature Window FEATURE ACTION BAR     before calling setContentView   method

User · Answer

I know I am late to the party  and new to Android  on this question but I found the information here very helpful and thought I should add the findings of my own endeavours with getting ActionBar to work as I wanted in case others like me come looking for help   I have a widget which is a floating window with no window title  I use a style theme to implement android windowIsFloating  android backgroundDimEnabled and android windowNoTitle  The widget worked fine until I wanted to add a button that called a fragment pager with several list fragment pages and used the ActionBar  It would crash on the pager activity with a null pointer exception  I narrowed it down to the ActionBar  being null  Following the findings of previous people who contributed to this thread I removed my theme from the manifest file and the ActionBar worked fine but now my window now longer floated  it was fullscreen  and it had a page title I did not want   Further research took me to the Styles and Themes API Training Guide which led me to a solution  I discovered I could add my custom theme to individual activities in the manifest file whereas before I was applying it to the application  All my windows now have the desired appearance

User · Answer

This answer is late but might be helpful to anyone who arrives from Google  You might well need to declare   lt item name  android windowActionBar  gt true lt  item gt    in your styles xml  It seems false can be the default  You also need to be on API 11 or higher   More details can be found in the documentation here  Specifically  quote      Tip  If you have a custom activity theme in which you d like to remove   the action bar  set the android windowActionBar style property to   false  However  if you remove the action bar using a theme  then the   window will not allow the action bar at all  so you cannot add it   later   calling getActionBar   will return null

User · Answer

ActionBar needs application or activity s Theme to have an app title  Make sure you have not styled your application or activity as Theme NOTITLE    lt application     android name  com xxx yyy      android debuggable  false      android icon   drawable icon      android label   string app name      android theme   style Theme NoTitle  gt     remove this line if you have this in your code    lt activity         android name  com xxx yyy Activity          android configChanges  orientation keyboardHidden screenSize          android theme   style Theme NoTitle      remove this line if you have in your code         android windowSoftInputMode  adjustResize stateHidden   gt

User · Answer

if you are using android support v7 app AppCompatActivity    public class HomeActivity extends AppCompatActivity     Then you should be using android support v7 app ActionBar     ActionBar ab   getSupportActionBar       If you are using android support v4 app FragmentActivity  public class HomeActivity extends FragmentActivity     then you should be using android app ActionBar      ActionBar ab   getActionBar       If you are using  android support v7 app ActionBarActivity  public class HomeActivity extends ActionBarActivity     you should be using  android support v7 app ActionBar     ActionBar ab   getSupportActionBar

User · Answer

I had the same issue  It solved by chaning App theme in styles xml  Before   lt  -- Base application theme  -- gt   lt style name  AppTheme  parent  Theme AppCompat Light DarkActionBar  gt    After   lt  -- Base application theme  -- gt   lt style name  AppTheme  parent  android Theme Holo Light DarkActionBar  gt

User · Answer

I solve it by this changes    change in minifest android theme   android style Theme Holo Light   gt  add to class extends ActionBarActivity add import to class import android support v7 app ActionBarActivity

[android] getActionBar() returns null

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