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. T

Answer 1

I had the same issue. It solved by chaning App theme in styles.xml

Before

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

After

<!-- Base application theme. -->
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">

Answer 2

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.

Answer 3

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 !!

Answer 4

You have to define window type as actionbar before activity render its view.

use

requestWindowFeature(Window.FEATURE_ACTION_BAR);

before calling setContentView() method.

Answer 5

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() { <-----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

Answer 6

android.support.v7.app.ActionBar actionBar = getSupportActionBar();

works pretty quickly