Kotlin 进阶 学习 委托

1.接口委托

package com.jmj.jetpackcomposecompositionlocal.byStudy

/**
 * 接口委托
 */
interface HomeDao{
    fun getAllData():List<String>
}

interface ADao{
        fun getById(id:Int):String
}

class HomeDaoImpl:HomeDao{
    override fun getAllData(): List<String> {
        return listOf("home")
    }

}
class ADaoImpl:ADao{
    override fun getById(id: Int): String {
        return "object id = $id"
    }

}
//这里多态也可以
class HomeService(homeDaoImpl: HomeDaoImpl,aDao: ADao):HomeDao by homeDaoImpl,ADao by aDao{
    fun getRedisData():String{
        return "redis"
    }
}

fun main() {
    val homeService = HomeService(HomeDaoImpl(),ADaoImpl())
    val allData = homeService.getAllData()
    println(allData)

    println(homeService.getById(3))
}

2.属性委托

package com.jmj.jetpackcomposecompositionlocal.byStudy

import kotlin.properties.ReadOnlyProperty
import kotlin.properties.ReadW