How to enable night mode programmatically?

Question

I am looking for a way to enable night mode programmatically with an Android code:

public static void setNightMode(Context target, boolean state){      UiModeManager uiManager = (UiModeManager) target.getSystemService(Context.UI_MODE_SERVICE);      if (state) {         //uiManager.enableCarMode(0);         uiManager.setNightMode(UiModeManager.MODE_NIGHT_YES);     } else {         // uiManager.disableCarMode(0);         uiManager.setNightMode(UiModeManager.MODE_NIGHT_NO);     } } 

Nothing has changed on my screen, the night mode is still disables. According to this link

There is no need to enable carMode or deskMode. I have the following logcat on Android Studio:

11-26 12:15:16.662 3823-3823/? D/UiModeManager: updateConfigurationLocked: mDockState=0; mCarMode=false; mNightMode=2; uiMode=33 11-26 12:15:26.802 3823-3823/? V/UiModeManager: updateLocked: null action, mDockState=0, category=null 

Answer 1

SIMPLEST SOLUTION

You can enable/disable application's dark theme just by:

1. enable dark theme:

    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES) 

2. forcefully disable dark theme:

    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO) 

3. set app theme based on mobile settings of dark mode, i.e. if dark mode is enabled then the theme will be set to a dark theme, if not then the default theme, but this will only work in version >= Android version Q (10)

    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM) 

Notes:

1. Your base theme for app/activity should be

"Theme.AppCompat.DayNight"

like

<style name="DarkTheme" parent="Theme.AppCompat.DayNight">     <item name="windowActionBar">false</item>     <item name="windowNoTitle">true</item> </style> 

2. Your res folder's names would end with -night so that different colors and images you can set for day and night themes like

drawable & drawable-night,
values & values-night

Answer 2

Make sure to change the default theme from Theme.AppCompat.Light.DarkActionBar to Theme.AppCompat.DayNight.DarkActionBar in the styles.xml file and then do AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES) to switch to the night mode. I have tested it in APIv23(Android 6.0) and above and it is working fine. For a better explanation see this codelab by Android