Kotlin + Google mvp 实现新的架构模式

来源：互联网发布：创维酷开系统下载软件编辑：程序博客网时间：2024/04/28 02:36

转载请注明出处：http://blog.csdn.net/yianemail/article/details/53114630

一：介绍

Kotlin是由JetBrains设计的开放源码的编程语言，它正在Java开发者中变得越来越流行。Kotlin通常被吹捧为Java的继承者，相比较Java而言，Kotlin提供更为丰富的开发经验，因为它更现代，更具表现力和更简介。

如果你在寻求Android开发的可替代编程语言，那么应该试一下Kotlin。使用Kotlin，你可以很容易的在Android工程中替代Java或者与Java混合使用。

本文接下来将介绍在Android Studio工程中如何使用Kotlin .

Kotlin ： https://kotlinlang.org/

二：Kotlin Studio 集成

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app/build.gradle

apply plugin: 'com.android.application'//add kotlin pluginapply plugin: 'kotlin-android'apply plugin: 'kotlin-android-extensions'android {    compileSdkVersion 25    buildToolsVersion "25.0.0"    defaultConfig {        applicationId "com.example.huanjulu.kotlinsource"        minSdkVersion 21        targetSdkVersion 25        versionCode 1        versionName "1.0"        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"    }    buildTypes {        //...    }    sourceSets {        main.java.srcDirs += 'src/main/kotlin'    }}dependencies {    compile fileTree(dir: 'libs', include: ['*.jar'])    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"}repositories {    mavenCentral()}

project/build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.buildscript {    ext.kotlin_version = '1.0.5'    repositories {        jcenter()    }    dependencies {        classpath 'com.android.tools.build:gradle:2.2.2'        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"        classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"        // NOTE: Do not place your application dependencies here; they belong        // in the individual module build.gradle files    }}allprojects {    repositories {        jcenter()    }}task clean(type: Delete) {    delete rootProject.buildDir}

三：代码实例

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MainActivity.kt

/** * Created by huanjulu on 16/11/9. */class MainActivity : AppCompatActivity(), UserSessionContract.UserSessionView {    var mPresenter: UserSessionContract.UserSessionPresenter? = null    //Adapter    var adapter: Adapter = Adapter(this)    //实例化LinearLayoutManager    var linearlayout = LinearLayoutManager(this)    override fun onCreate(savedInstanceState: Bundle?) {        super.onCreate(savedInstanceState)        setContentView(R.layout.activity_main)        //start 订阅        UserSessionPresenter(this).subscribe()        mPresenter!!.dataP(null)        //设置adapter 以及 layoutManager        recycleview.adapter = adapter        recycleview.layoutManager = linearlayout    }    override fun onDestroy() {        super.onDestroy()        //cancle 订阅        mPresenter!!.unSubscribe()    }    override fun <T> dataV(t: T?) {        t as List<String>        //非空调用        adapter!!.load(t)    }    override fun setPresenter(p: UserSessionContract.UserSessionPresenter) {        this.mPresenter = p    }}

其中的remote data 模拟了一些网络数据

UserSessionRemoteImpl.kt

/** * Created by huanjulu on 16/11/9. */class UserSessionRemoteImpl : UserSessionRemote {    var data: List<UserSessionWrap> = listOf(UserSessionWrap(), UserSessionWrap(), UserSessionWrap(), UserSessionWrap(), UserSessionWrap(), UserSessionWrap())    var datas: List<String> = listOf(            "稀土攫金"            , "泡在网上的日子",            "cokk", "V2ex",            "开发头条",            "23code"    )    override fun <T> dataRemote(t: T?): List<String> {        data.forEach {        }        return datas    }}

Adapter.kt

/** * Created by huanjulu on 16/11/9. */class Adapter constructor(context: Context) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {    val mContext: Context?    companion object {    }    init {        this.mContext = context    }    val items = LinkedList<String>()    override fun onBindViewHolder(holder: RecyclerView.ViewHolder?, position: Int) {        (holder as ViewHolder).bind(items[position])    }    override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): RecyclerView.ViewHolder {        val view = LayoutInflater.from(parent?.context).inflate(R.layout.item_data, parent, false)        return ViewHolder(view)    }    fun load(articles: List<String>) {        if (articles.isNotEmpty()) {            items.run {                clear()                addAll(articles)                notifyDataSetChanged()            }        }    }    override fun getItemCount(): Int = items.size    inner class ViewHolder(val view: View) : RecyclerView.ViewHolder(view) {        fun bind(item: String) {            view.run {                tag = this                Log.d("TAG", item)                content.text = item            }        }    }}

效果

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四：结语

在使用完Kotlin之后，

干净整洁，代码量少了一半左右
类型推断，扩展方法
when while if 表达式更加方便
和JAVA调用很方便，能直接使用原有的JAVA方法
是它可以配合ANKO（虽然ANKO现在还不支持JAVA8））,从此告别XML布局

代码下载：https://github.com/outparadox/KoltinDemo.git

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