sakshampruthi

when(SaveSharedPrefernce.getChecktheme(applicationContext)) {
    0 -> AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM)
    1 -> AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
    2 -> AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
}

sakshampruthi

class MainActivity : AppCompatActivity() {

    var selection: String? = null
    var checked_item = 0
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        
        val theme = applicationContext.resources.getStringArray(R.array.theme)

sakshampruthi

object SaveSharedPrefernce {
    const val CHECKTHEME = "checkTheme"
    fun getSharedPreferences(ctx: Context?): SharedPreferences {
        return PreferenceManager.getDefaultSharedPreferences(ctx)
    }

    fun setChecktheme(context: Context?, check: Int) {
        val editor = getSharedPreferences(context).edit()
        editor.putInt(CHECKTHEME, check)
        editor.apply()