If the system theme is light and the app theme is dark, the actionbar items are dark when the app startup. (left picture) When I reload the dark theme again from the in-app settings, the actionbar items are light (as I want) (right picture). This problem only happens in MainActivity. How can fix this problem?

MainActivity.java

protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                PreferenceManager.setDefaultValues(this, R.xml.preferences, true);
                PreferenceUtils.setTheme(this);
                setContentView(R.layout.activity_main);
                if (getSupportActionBar() != null) {
                    this.getSupportActionBar().setElevation(0);
                }
                setTitle("Sample App");
    
            drawerLayout = findViewById(R.id.drawer_layout);
            drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.nav_drawer_open, R.string.nav_drawer_close);
            drawerLayout.addDrawerListener(drawerToggle);
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setHomeButtonEnabled(true);
            drawerToggle.syncState();
    
            navigationView = findViewById(R.id.nav_view);
            navigationView.setNavigationItemSelectedListener(this);
                .
                .
                .

PreferenceUtils.java

public class PreferenceUtils {

    public static final String LIGHT_MODE = "light";
    public static final String DARK_MODE = "dark";

    public static void setTheme(Activity activity) {
        switch (PreferenceManager.getDefaultSharedPreferences(activity).getString("pref_key_theme"), "")) {
            case LIGHT_MODE: {
                AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
                break;
            } case DARK_MODE: {
                AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
                break;
            } default: {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);
                } else {
                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY);
                }
                break;
            }
        }
    }
}

activity_main.xml

<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@ id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="false"
    tools:context=".MainActivity"
    tools:openDrawer="start">

    <RelativeLayout
        android:id="@ id/main_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.material.tabs.TabLayout
            android:id="@ id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:minHeight="?attr/actionBarSize"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:tabIndicatorColor="?attr/colorAccent"
            app:tabSelectedTextColor="?android:textColorPrimary"
            app:tabTextColor="?android:textColorSecondary"
            app:tabMode="fixed" />     
    </RelativeLayout>

    <com.google.android.material.navigation.NavigationView
        android:id="@ id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header_main"
        app:menu="@menu/main_drawer" />
</androidx.drawerlayout.widget.DrawerLayout>

themes.xml

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Theme.SampleApp" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <!-- Primary brand color. -->
        <item name="colorPrimary">@color/red_800</item>
        <item name="colorPrimaryVariant">@color/red_900</item>
        <item name="colorOnPrimary">@color/white</item>
        <!-- Secondary brand color. -->
        <item name="colorSecondary">@color/red_700</item>
        <item name="colorSecondaryVariant">@color/red_700</item>
        <item name="colorOnSecondary">@color/black</item>
        <!-- Status bar color. -->
        <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
    </style>
</resources>

themes-night.xml

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Theme.SampleApp" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <!-- Primary brand color. -->
        <item name="colorPrimary">@color/dark_grey_900</item>
        <item name="colorPrimaryVariant">@color/black</item>
        <item name="colorOnPrimary">@color/black</item>
        <!-- Secondary brand color. -->
        <item name="colorSecondary">@color/blue_200</item>
        <item name="colorSecondaryVariant">@color/blue_200</item>
        <item name="colorOnSecondary">@color/black</item>
        <!-- Status bar color. -->
        <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
    </style>
</resources>

manifest

<application
        android:allowBackup="true"
        android:fullBackupContent="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:theme="@style/Theme.SampleApp">         
        <activity android:name=".MainActivity" android:configChanges="locale|orientation|screenSize|keyboardHidden|uiMode" android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

CodePudding user response：

I am not sure but i guess you can try to set it onViewCreated to be sure view created when you apply theme.

CodePudding user response：

PreferenceManager.setDefaultValues(this, R.xml.preferences, true); 

what does this do? If it used to set default values then remove this line and you should use preference.getBoolean(key, defaultValue) even if u have not set preference u can get Default values