Question

I am developing an android application.
I want to add a feature to let the user to change the application’s theme at the runtime.

I try to use the following statement in my main activity.

setTheme(android.R.style.Theme_Black);

However, it merely change the dialog to black background with white text.

What can I do to change all the componenets’ theme to Black including the action bar and fragment?

Answer 1

For a global runtime change, what could work is extending Application and setting the theme (probably in onCreate(), since this class also has a setTheme() method on account of it extending ContextWrapper.

Make sure to declare your Application class in the manifest:

<application
        android:name="com.yourpackage.ApplicationClass" >
</application>

However, since extending application is usually frowned upon, I’d rather set the theme on a per Activity basis since Activities get destroyed and recreated way more often than the Application object. Maybe make a static method that returns the current theme from SharedPreferences.