AndroidX首选项库DropDownPreferences在API <24上不起作用

Question

I've finished migrating to AndroidX Preference library and while everything works perfect on API 24-29, it reacts weirdly on older ones<24. The Dropdown preferences are not responding on selection but the dialog ones are. What changed on API 24 that might cause this? I should mention that the official Github sample app works as intended even on API 16!

UPDATE - I've managed to find a temporary workaround, by changing DropDownPreference s to ListPreference . However, it didn't fix it yet. But after applying another theme (as in the clip below - between Light\\Dark) the value of the ListPreference changed and work properly! (The theme changing is done by AppCompatDelegate.setDefaultNightMode and getActivity().recreate() )

AVD API 29 (also 24-28) - Everything works:

AVD API 21 (also 22-23) - Nothing happens when choosing other options

(While we're at it - any way to decrease the size of the emulator video capture?)

Here is my preferences.xml:

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <PreferenceCategory
        android:key="general_settings"
        android:title="@string/settings_title_general">

        <ListPreference
            android:defaultValue="system"
            android:entries="@array/locale"
            android:entryValues="@array/localeValues"
            android:key="locale_override"
            android:summary="@string/settings_locale_summary"
            android:title="@string/settings_locale_title"
            app:useSimpleSummaryProvider="true" />

        <DropDownPreference
            android:defaultValue="@string/settings_units_option_default"
            android:entries="@array/unitOfMeasure"
            android:entryValues="@array/unitOfMeasureValues"
            android:key="unit_of_measure"
            android:summary="@string/settings_uom_summary"
            android:title="@string/settings_uom_title"
            app:useSimpleSummaryProvider="true" />

        <DropDownPreference
            android:defaultValue="@string/settings_theme_option_default"
            android:entries="@array/theme"
            android:entryValues="@array/themeValues"
            android:key="theme"
            android:summary="@string/settings_theme_summary"
            android:title="@string/settings_theme_title"
            app:useSimpleSummaryProvider="true" />

        <DropDownPreference
            android:defaultValue="Internal"
            android:entries="@array/storage"
            android:entryValues="@array/storageValues"
            android:key="storage_location"
            android:summary="@string/settings_storage_summary"
            android:title="@string/settings_storage_title"
            app:useSimpleSummaryProvider="true" />
    </PreferenceCategory>

    <PreferenceCategory
        android:key="about"
        android:title="@string/settings_title_about">

        <Preference
            android:key="version"
            android:title="@string/settings_version_title"
            app:enableCopying="true"
            app:selectable="false" />

        <Preference
            android:key="privacy_policy"
            android:summary="Read the privacy policy that Google made us put up..."
            android:title="Privacy Policy">

            <intent
                android:action="android.intent.action.VIEW"
                android:data="https://sites.google.com/site/skydivinglogbook/privacy-policy" />
        </Preference>

and the SettingFragment:

public class SettingsFragment extends PreferenceFragmentCompat {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mContext = getActivity();
        settingsRepository = new SettingsRepository(mContext);
        LocaleHelper.updateResources(mContext);
    }

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        setPreferencesFromResource(R.xml.preferences, rootKey);

        //version name
        findPreference(Constants.PREF_KEY_VERSION).setSummary(BuildConfig.VERSION_NAME);
    }
    </PreferenceCategory>
</PreferenceScreen>

Answer 1

You're not using any androidx.preference.* in the XML, alike:

androidx.preference.PreferenceScreen
androidx.preference.PreferenceCategory
androidx.preference.Preference
androidx.preference.ListPreference
androidx.preference.DropDownPreference

so you probably cannot refer to AndroidX.

That useSimpleSummaryProvider is useless, when not being used with androidx.preference >= 1.1.0 .