BooleanPreference.kt

import android.content.SharedPreferences
import uz.avtobio.app.extension.edit
import kotlin.properties.ReadWriteProperty
import kotlin.reflect.KProperty

class BooleanPreference(
        private val pref: SharedPreferences,
        private val key: String,
        private val defValue: Boolean = false
) : ReadWriteProperty<Any, Boolean> {
    override fun getValue(thisRef: Any, property: KProperty<*>) = pref.getBoolean(key, defValue)
    override fun setValue(thisRef: Any, property: KProperty<*>, value: Boolean) = pref.edit { putBoolean(key, value) }
}

Example

val pref:IPreference = Preference(...)
pref.userPhoneNumber="+998971234567"// prefga yozish uchun
val tel = pref.userPhoneNumber//pref dan o'qish uchun

IntPreference.kt

import android.content.SharedPreferences
import uz.avtobio.app.extension.edit
import kotlin.properties.ReadWriteProperty
import kotlin.reflect.KProperty

class IntPreference(
    private val pref: SharedPreferences,
    private val key: String,
    private val defValue: Int = -1
) : ReadWriteProperty<Any, Int> {
    override fun getValue(thisRef: Any, property: KProperty<*>) = pref.getInt(key, defValue)
    override fun setValue(thisRef: Any, property: KProperty<*>, value: Int) =
        pref.edit { putInt(key, value) }
}

IPreference.kt

interface IPreference {
    var userPhoneNumber: String
}

LongPreference.kt

class LongPreference(
    private val pref: SharedPreferences,
    private val key: String,
    private val defValue: Long = 0L
) : ReadWriteProperty<Any, Long> {
    override fun getValue(thisRef: Any, property: KProperty<*>) = pref.getLong(key, defValue)
    override fun setValue(thisRef: Any, property: KProperty<*>, value: Long) =
        pref.edit { putLong(key, value) }
}

Preference.kt

import android.content.SharedPreferences
import uz.avtobio.app.data.pref.data_types.StringPreference

const val KEY_PHONE_NUMBER = "KEY_PHONE_NUMBER"

class Preference(pref: SharedPreferences) : IPreference {

    override var userPhoneNumber: String by StringPreference(pref, KEY_PHONE_NUMBER, "")

}

StringPreference.kt

class StringPreference(
    private val pref: SharedPreferences,
    private val key: String,
    private val defValue: String = ""
) : ReadWriteProperty<Any, String> {
    override fun getValue(thisRef: Any, property: KProperty<*>): String =
        pref.getString(key, defValue) ?: ""

    override fun setValue(thisRef: Any, property: KProperty<*>, value: String) =
        pref.edit { putString(key, value) }
}