Implement day/night system in your Android app using Android Studio

In this article, you will learn how to switch Day mode > Night mode and Night mode > Day mode. We try to discuss it simple way. So let’s see:

Step 1: Set up res/values/themes.xml for day mode app screen

<style name="Theme.MyApp" parent="Theme.MaterialComponents.Light">
    <item name="colorPrimary">#2196F3</item>
    <item name="colorPrimaryVariant">#1976D2</item>
    <item name="colorOnPrimary">#FFFFFF</item>
</style>

Step 2: Set up res/values-night/themes.xml for day mode app screen

<style name="Theme.MyApp" parent="Theme.MaterialComponents.Dark">
    <item name="colorPrimary">#121212</item>
    <item name="colorPrimaryVariant">#000000</item>
    <item name="colorOnPrimary">#FFFFFF</item>
</style>

Step 3: Handle Day/Night Mode Using a Toggle Switch

switchTheme.setOnCheckedChangeListener((buttonView, isChecked) -> {
    SharedPreferences.Editor editor = prefs.edit();
    editor.putBoolean("dark_mode", isChecked);
    editor.apply();

    if (isChecked) {
        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
    } else {
        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
    }
   overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out); // with animation
});

Check & Active Manually

SharedPreferences prefs = getSharedPreferences("settings", MODE_PRIVATE);
if (prefs.getBoolean("dark_mode", false)) {
    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
} else {
    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
}