How to use OnSharedPreferenceChangeListener in Kotlin?

Question

I have a Activity that has variable number and a (InputMethodService) Service class that gets a number from the activity.

What I want is that when I change variable number in activity, that reflects on service class.

So I wrote the code like this, but It didn't work. Is there a mistake or wrong code?

class Activity : AppCompatActivity() {
    override fun onCreate() {
        var customNumber: Int = 100

        val myPreference = getSharedPreference("number", Context.MODE_PRIVATE)
        myPreference.edit().putInt("changeNumber", customNumber).apply()
    }
}

in Service ( get number from activity )

class myService : InputMethodService(), SharedPreferences.OnSharedPreferenceChangeListener {

    var changedNumber: Int = 0

    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
    changedNumber = sharedPrefrences!!.getInt("changeNumber", 0)
    }
}

Answer 1

It looks like you're forgetting to register/unregister the listener:

https://stackoverflow.com/a/3799894/7434090