xml - Android - Actionbar not showing in the development preview

Question

Actionbar not showing in the development preview but showing normally after running the app, minimum api is 15, tried to delete the them from the manifest file, didn't show the actionbar, and can't run the app anymore.

It is a completely new project (tried deleting it and recreating it and creating several other with different minimum api, still not showing in the development)

My theme is blank with a parent "parent="Theme.AppCompat.Light.DarkActionBar""

Trying to use a holo light theme, crashed and got that error "java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity."

Default activity extends actionbaractivity instead of activity, fixed now. Thanks

Answer 1

If you can't see the action bar AND also the status bar or buttons, it could be because the "Show Layout Decorations" options is turned off in the Layout Editor. Just check this option and everything should be displayed again. As per Android Studio 3.3: