Kotlin mpp 记录2

在gradle加了相关序列化和协程的依赖
之后common中加入entity

package com.example.mympp0application.entity

import kotlinx.serialization.SerialName
import kotlinx.serialization.Serializable

@Serializable
data class RocketLaunch (
    @SerialName("flight_number")
    val flightNumber:Int,
    @SerialName("name")
    val missionName:String,
    @SerialName("date_utc")
    val launchDateUTC:String,
    @SerialName("success")
    val launchSuccess:Boolean?,
)

再引入ktor（一个支持kotlin的http框架）
更改欢迎页
可以看到标注的一行进行了httpClient调用

package com.example.mympp0application

import com.example.mympp0application.entity.RocketLaunch
import io.ktor.client.*
import io.ktor.client.call.*
import io.ktor.client.plugins.contentnegotiation.*
import io.ktor.client.request.*
import io.ktor.serialization.kotlinx.json.*
import kotlinx.serialization.json.Json

class Greeting {

    private val httpClient= HttpClient{
        install(ContentNegotiation){
            json(Json{
                prettyPrint=true
                isLenient=true
                ignoreUnknownKeys=true
            })
        }
    }

    @Throws(Exception::class)
    suspend fun greeting(): String {
        val rockets:List<RocketLaunch> = httpClient.get("https://api.spacexdata.com/v4/launches").body()
        val lastSuccessLaunch = rockets.last {it.launchSuccess==true}
        return "Hello, ${Platform().platform.reversed()}!"+
                "\nThere are only ${daysUntilNewYear()} left until New Year!"+
                "\nThe last successful launch was ${lastSuccessLaunch.launchDateUTC} ð"
    }

}

下面在安卓端和IOS端都进行了greeting的调用：

Android：

package com.example.mympp0application.android

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.mympp0application.Greeting
import android.widget.TextView
import kotlinx.coroutines.MainScope
import kotlinx.coroutines.cancel
import kotlinx.coroutines.launch

class MainActivity : AppCompatActivity() {
    private val scope = MainScope()

    override fun onDestroy() {
        super.onDestroy()
        scope.cancel()
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val tv: TextView = findViewById(R.id.text_view)
        tv.text = "Loading..."

        scope.launch {
            kotlin.runCatching{
                /**
                 * The greeting() function is now called
                 * inside the coroutine launched in the main
                 * CoroutineScope
                 */
                Greeting().greeting()
            }.onSuccess {
                tv.text=it
            }.onFailure {
                tv.text=it.localizedMessage
            }
        }
    }
}

IOS:

import SwiftUI
import shared

struct ContentView: View {
    @ObservedObject private(set) var viewModel:ViewModel
    
    var body: some View {
        Text(viewModel.text)
    }
}

extension ContentView{
    class ViewModel: ObservableObject{
        @Published var text = "Loading..."
        init(){
            Greeting().greeting{
                greeting,error in
                /**
                 When calling Kotlin suspend functions from Swift,
                 completion handlers might be called on threads other thant the main one
                 Tha's why DispatchQueue.main.async is used to update the text property
                 */
                DispatchQueue.main.async{
                    //Data will be loaded here
                    if let greeting = greeting {
                        self.text = greeting
                    }else{
                        self.text = error?.localizedDescription ?? "error"
                    }
                }
            }
      
        }
    }
}