NullPointerException: with ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference

Question

I get this nullPointerException on runtime:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method \'void android.app.ActionB

Answer 1

If you check this answer in 2019 like me , the problem is about your android manifest:

Check the documentation here:

https://developer.android.com/training/appbar/setting-up.html

You also take in mind the previous answer from TetianaDev:

Instead of:

public class MainActivity extends Activity {

use:

public class MainActivity extends AppCompatActivity {

and instead of:

getActionBar().setTitle(mTitles);

use:

getSupportActionBar().setTitle(mTitles);

This works for me.