1.List的lambda中直接访问变量

fun testList() {
    val list = listOf(11, 2, 3, 4, 5, 6, 7, 8, 9, 10)
    var count = 0

    //在lambda中可以直接操作变量
    list.forEach {
        count++
    }

    println("count:$count")

    //遍历索引
    list.indices.forEach {
        println("$it")
    }
}

2.使用Object来管理单例Service的注册

初始化

fun testService() {
    ServiceListManager.init()
}

IService

interface IService {
    fun init()

    val order: Int
        get() = 1
}

具体的Service

package service

object AccountService : IService {
    override fun init() {
        println("AccountService init")
    }

    override val order: Int
        get() {
            return 3
        }
}

ServiceListManager

package service

object ServiceListManager {
    private val serviceList = mutableListOf<IService>(
        LoginService,
        AccountService
    )

    fun init() {
        //先排序一下
        serviceList.sortBy { it.order }

        //初始化
        serviceList.forEach {
            it.init()
        }
    }
}

3.泛型json和map互转

package com.example.demo

import kotlinx.serialization.json.Json

suspend fun main(args: Array<String>) {

    val JsonUtilV2 = Json { ignoreUnknownKeys = true; isLenient = true }

    val map = mapOf(
        "a" to 1,
        "b" to 2,
        "c" to 3
    )

    //map转json
    val jsonStr = JsonUtilV2.encodeToString(map)
    println(jsonStr)

    //转为map不需要传递TypeReference
    val beanMap: Map<String, Int> = JsonUtilV2.decodeFromString(jsonStr)
    println(beanMap)
}