PreferenceManager getDefaultSharedPreferences deprecated in Android Q

You can use the Android 10 support library version of PreferenceManager, i.e., androidx.preference.PreferenceManager and not android.preference.PreferenceManager.

Remember to add the following to your build.gradle:

implementation 'androidx.preference:preference:1.1.1'

Package preference provides the androidx PreferenceManager:

Java: implementation "androidx.preference:preference:1.1.1"

Kotlin: implementation "androidx.preference:preference-ktx:1.1.1"

i.e. change android.preference.PreferenceManager to androidx.preference.PreferenceManager

Also see PreferenceFragmentCompat, which is the current PreferenceFragment class to use.

If you're just saving and retrieving key-value pairs you can replace:

 prefs = PreferenceManager.getDefaultSharedPreferences(this); 

with:

 prefs = getSharedPreferences(
            "my.app.packagename_preferences", Context.MODE_PRIVATE);

Be sure to use the right file name for the new implementation or your users will lose access to everything saved with getDefaultSharedPreferences(!). The following will get the file name getDefaultSharedPreferences uses:

getPackageName() + "_preferences"