How to make dark mode in every activity

问题

When I click night mode button it only apply in settings activity but other activities are not night mode.

This is xml
<Switch
        android:id="@+id/switch_button"
        android:layout_marginStart="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/night"/>

This is SettingsActivity
Switch aSwitch = findViewById(R.id.switch_button);
    aSwitch.setOnCheckedChangeListener((compoundButton, isChecked) -> {
        if (isChecked) {
            getDelegate().setLocalNightMode(AppCompatDelegate.MODE_NIGHT_YES);
        }
        else
        {
            getDelegate().setLocalNightMode(AppCompatDelegate.MODE_NIGHT_NO);
        }
    });

And also when I close app and open again, night mode is not saved. How to do that?

回答1:

Try this:

1. Make sure that the activities extends AppCompatActivity.

2. Your theme must use Theme.AppCompat.DayNight therefore you should set your main theme or AppTheme to DayNight:

   <style name="AppTheme" parent="Theme.AppCompat.DayNight">
   

3. Set the theme of your Activities in your AndroidManifest to:

   android:theme="@style/AppTheme"
   

or any theme that uses Theme.AppCompat.DayNight

来源：https://stackoverflow.com/questions/57421476/how-to-make-dark-mode-in-every-activity