如何进行暗模式设置

如何解决如何进行暗模式设置

我是android开发的新手，我希望在应用程序中进行暗模式设置。 为此，我创建了一个“ preferences.xml”文件，该文件使用“ SettingsActivity.java”文件和“ SettingsFragment.java”文件显示。我在互联网上寻找了很多解决方案，但是都没有用。有人有教程，示例或解决方案吗？ 谢谢

preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

    <ListPreference
            android:key="@string/key_app_theme"
            android:title="@string/app_theme"
            android:summary=""
            android:icon="@drawable/ic_app_theme"
            android:entries="@array/pref_app_theme_entries"
            android:entryValues="@array/pref_app_theme_values"
            android:dialogTitle="@string/app_theme"
            android:defaultValue="1"/>

</PreferenceScreen>

arrays.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    
    <string-array name="pref_app_theme_entries">
        <item>@string/system</item>
        <item>@string/battery_saver</item>
        <item>@string/light</item>
        <item>@string/dark</item>
    </string-array>
    <string-array name="pref_app_theme_values">
        <item>1</item>
        <item>2</item>
        <item>3</item>
        <item>4</item>
    </string-array>
    
</resources>

activity_settings.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_settings"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary"
    tools:context=".SettingsActivity">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/activity_settings_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:elevation="4dp"
        android:background="@color/colorPrimaryDark"
        app:title="@string/settings"
        app:titleTextColor="@color/colorAccent" />

    <FrameLayout
        android:id="@+id/activity_settings_fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/activity_settings_toolbar" />

</RelativeLayout>

SettingsActivity.java

public class SettingsActivity extends AppCompatActivity {

    private static Preference settings;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_settings);

        if (findViewById(R.id.activity_settings_fragment_container) !=null) {
            if (savedInstanceState != null)
                return;

            getFragmentManager().beginTransaction().add(R.id.activity_settings_fragment_container,new SettingsFragment()).commit();
        }

        Toolbar toolbar = findViewById(R.id.activity_settings_toolbar);
        toolbar.setTitleTextAppearance(this,R.style.KaushanScriptRegular);
        toolbar.setNavigationIcon(R.drawable.ic_back);
        toolbar.setNavigationOnClickListener(view -> {
            Intent intent = new Intent(SettingsActivity.this,MainActivity.class);
            startActivity(intent);
            overridePendingTransition(R.anim.swipe_right_enter,R.anim.swipe_right_exit);
        });
    }
}

SettingsFragment.java

public class SettingsFragment extends PreferenceFragment {

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        addPreferencesFromResource(R.xml.preferences);
}

解决方法

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.night_mode) {
            // Get the night mode state of the app.
            int nightMode = AppCompatDelegate.getDefaultNightMode();
            //Set the theme mode for the restarted activity
            if (nightMode == AppCompatDelegate.MODE_NIGHT_YES) {
                AppCompatDelegate.setDefaultNightMode
                        (AppCompatDelegate.MODE_NIGHT_NO);
            } else {
                AppCompatDelegate.setDefaultNightMode
                        (AppCompatDelegate.MODE_NIGHT_YES);
            }
// Recreate activity for the theme change to take effect.
            recreate();

        }
        return super.onOptionsItemSelected(item);
    }

此外，您可以选择Check Theme Style

,

有关开发夜间模式的信息，请参阅以下视频： Night/Dark Mode Tutorial

它在Kotlin中给出，但是到Java的翻译非常简单。 收听SharedPreferences：

int theme = Integer.valueOf(sharedPreferences.getString("theme","1"));
switch (theme) {
    case 3 :
        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
        break;
    case 4 :
        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
        break;
    case 2 :
        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY);
        break;
    default :
        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM);

（假设您的主题设置的“首选项”键是“主题”。） 其余代码位于XML文件中，因此当使用Java代替Kotlin时，它不会改变。