Kotlin Android Extensions+Android MVP项目(RxJava+Rerotfit+OkHttp+Glide)

r囧r小猫 2022-06-14 04:40 156阅读 0赞

**Kotlin编程开发Android运用程序的相关介绍**：

*  [Kotlin编程之AndroidStudio（包括3.0与2.x版本）配置与使用][Kotlin_AndroidStudio_3.0_2.x]
 *  [ Kotlin编程开发Android运用程序（Volley+Gson依赖库）][Kotlin_Android_Volley_Gson]
 *  [Kotlin编程之Kotlin Android Extensions（扩展插件）][Kotlin_Kotlin Android Extensions]
 *  [Kotlin编程之Glide v4 Generated API(Unresolved reference GlideApp)][Kotlin_Glide v4 Generated API_Unresolved reference GlideApp]

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## **Kotlin编写MVP案例** ##

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使用Kotlin编程实现一个MVP案例，实现电影列表功能：

![这里写图片描述][SouthEast]

### **前期准备**： ###

项目中，在Gradle中引入框架的配置如下和使用Kotlin Android扩展：

apply plugin: 'com.android.application'
    apply plugin: 'kotlin-android'
    apply plugin: 'kotlin-android-extensions'//扩展插件
    
    dependencies {
        compile fileTree(include: ['*.jar'], dir: 'libs')
        androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
            exclude group: 'com.android.support', module: 'support-annotations'
        })
        compile 'com.android.support:appcompat-v7:25.3.1'
        compile 'com.android.support:design:25.3.1'
        testCompile 'junit:junit:4.12'
        compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
        //Glide v4
        compile 'com.github.bumptech.glide:glide:4.0.0-RC0'
        annotationProcessor 'com.github.bumptech.glide:compiler:4.0.0-RC0'
        //Retrofit 2.x
        compile 'com.squareup.retrofit2:retrofit:2.3.0'
        compile 'com.squareup.retrofit2:converter-gson:2.3.0'
        compile 'com.squareup.retrofit2:adapter-rxjava:2.3.0'
        //OkHttp 3.x
        compile 'com.squareup.okhttp3:okhttp:3.8.0'
        compile 'com.squareup.okhttp3:logging-interceptor:3.8.0'
        //RxJava 1.x
        compile 'io.reactivex:rxjava:1.3.0'
        compile 'io.reactivex:rxandroid:1.2.1'
    }

##### **须注意点：本篇中无findViewById获取控件对象，采用Kotlin Android Extensions方式获取控件对象**。 #####

AndroidManifest.xml中添加权限：

<uses-permission android:name="android.permission.INTERNET"></uses-permission>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

除之外，还有各种框架的混淆规则，这里省略不贴。

**开始编写代码**：

### **1**. 项目通用的BasePrester和BaseView接口： ###

项目中通用的BasePresenter接口，具备订阅和取消订阅的行为：

interface  BasePresenter{
        /** * 订阅 */
        fun subscribe()
        /** * 取消订阅 */
         fun unsubscribe()
    }

项目中通用的BaseView接口,具备绑定Presenter的行为：

interface BaseView<T>{
        /** * 设置Presenter的方法 */
        fun  setPresenter(presenter: T)
    }

### **2. 开始编写Model中远程数据源** ###

采用Retrofit作为网络异步框架，OkHttp作为传输层。

这里，采用搜索张艺谋的电影，在douban的API中：`https://api.douban.com/v2/movie/search?q=张艺谋`

**Retrofit的请求和响应结果的配置**：请求中发送的Body和Header,Respose的接口 ：需要添加retrofit:adapter-rxjava库，实现适配器功能

interface DouBanService {
        /** * 这里返回一个Observable，用于RxJava结合使用 */
        @GET("{path}")
        fun movieList(@Path("path") path:String, @QueryMap options: Map<String,String> ):Observable<MovieList>
    }

**Retrofit的操作类**：添加OkHttp作为传输层，RxJava适配器，Gson解析的转换器。

object RemoteDataSource{
        val baseURL="https://api.douban.com/v2/movie/"
        val retrofit:Retrofit by lazy {
            Retrofit.Builder().baseUrl(baseURL)
                    .client(OkHttpProvider.createOkHttpClient())
                    .addConverterFactory(GsonConverterFactory.create())
                    .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                    .build()
        }
        var douBanService= retrofit.create(DouBanService::class.java)
    
        fun movieList(subscriber:Subscriber<List<MovieList.Movie>>):Subscription{
            val url="search"
            var map= hashMapOf("q" to "张艺谋" )
             var result= douBanService.movieList(url,map).flatMap {
                item: MovieList ->Observable.just(item.subjects)
            }.subscribeOn(Schedulers.io())
            .unsubscribeOn(Schedulers.io()) 
            .observeOn(AndroidSchedulers.mainThread()) 
            .subscribe(subscriber)
    
            return result
        }
    }

**OkHttp的配置**：需 引入OkHttp库和OkHttp:logging-interceptor库

internal class OkHttpProvider{ 
        companion object{
            /** * 自定义配置OkHttpClient */
            fun createOkHttpClient():OkHttpClient{
               var  builder=OkHttpClient.Builder()
                var  loggingInterceptor=HttpLoggingInterceptor()
                loggingInterceptor.level=HttpLoggingInterceptor.Level.BODY
                builder.addInterceptor(loggingInterceptor)
                return builder.build()
            }
        }
    }

**编写返回的实体类**：

data  class MovieList(var subjects:List<Movie>){
        data class Movie(var year:String,var title:String,var  images: Images){
            data class Images(var small:String,var large:String)
        }
    }

**加载图片的Glide v4的配置**：

在上篇已经详细介绍了，请阅读[Kotlin编程之Glide v4 Generated API(Unresolved reference GlideApp)][Kotlin_Glide v4 Generated API_Unresolved reference GlideApp]。

### **3. 根据模块业务编写View和Presenter及它的实现类** ###

业务上比较简单，搜索张艺谋的电影，显示在列表上。根据这个分析，写出这个模块的View和Presenter.

interface MovieListConstract{
        interface Presenter:BasePresenter
        /*** * 抽出Presenter对View的响应行为，在View接口中定义 */
        interface View :BaseView<Presenter>{
            fun showToast(msg:String)//Toast提示
            fun loadMovie(list: List<MovieList.Movie>)//加载电影数据
            fun showDialog()//显示dialog
            fun cancleDialog()//取消dialog
        }
    }

**View的实现类**: 在Fragment、Activity、Adapter中怎么使用Kotlin Android Extensions，请阅读上篇[ Kotlin编程之Kotlin Android Extensions（扩展插件）][Kotlin_Kotlin Android Extensions].

class MovieListFragment : Fragment(), MovieListConstract.View { lateinit var presenters: MovieListConstract.Presenter lateinit var dialog: ProgressDialog lateinit var rootView: View override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { rootView = inflater.inflate(R.layout.fragment_movielist, container, false) return rootView } override fun onResume() { super.onResume() presenters.subscribe() } override fun onPause() { super.onPause() presenters.unsubscribe() } override fun setPresenter(presenter: MovieListConstract.Presenter) { this.presenters = presenter } override fun showToast(msg: String) { Toast.makeText(activity.applicationContext, msg, Toast.LENGTH_SHORT).show() } /** * 加载数据 */ override fun loadMovie(list: List<MovieList.Movie>) { //无findViewById(),直接引用控件 var recyclerView = rootView.movieList_recyclverView recyclerView.layoutManager = LinearLayoutManager(activity) recyclerView.adapter = MovieListAdapter(activity, list) } override fun showDialog() { dialog = ProgressDialog(activity) dialog.show() } override fun cancleDialog() { if (dialog != null && dialog.isShowing) { dialog.cancel() } } companion object { //静态对象 val instance = MovieListFragment() //静态常量 val Tag = MovieListFragment::class.java.javaClass.simpleName } }

**RecyclerView中Adapter**：

import kotlinx.android.synthetic.main.movielist_item.view.*
    
    /** * Created by ${新根} on 2017/6/8. * blog ：http://blog.csdn.net/hexingen */
    internal class MovieListAdapter(var context: Context, var list: List<MovieList.Movie>) : RecyclerView.Adapter<MovieListAdapter.ViewHolder>() {
    
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) = 
                  ViewHolder(View.inflate(parent.context, R.layout.movielist_item, null)) 
    
        override fun onBindViewHolder(holder: ViewHolder, position: Int) {
            GlideUtils.loadUrlImage(context,list[position].images.large,holder.imageView)
            holder.title_Tv.text=list[position].title
        } 
    
        override fun getItemCount() = list.size 
    
        internal class ViewHolder(rootView: View) : RecyclerView.ViewHolder(rootView) {
            /** * 这里使用Kotlin Android 扩展，省略了findViewById（）. * 在最上面导入了import kotlinx.android.synthetic.main.movielist_item.view.* */
            var imageView = rootView.movielist_item_iv
            var title_Tv= rootView.movielist_item_tv
        }
    }

**Presenter的实现类**：

class MovieListPresenter(var view: MovieListConstract.View, var compositeSubscription: CompositeSubscription = defaultCompositeSubscription) : MovieListConstract.Presenter {
        init {
       //init初始化模块
            view.setPresenter(this)
        }
        //开始订阅
        override fun subscribe() {
            view.showDialog()
            excuteTask()
        }
        //执行任务
        fun excuteTask() {
          var  disposable=RemoteDataSource.movieList(object :Subscriber<List<MovieList.Movie>>() {
                override fun onNext(t: List<MovieList.Movie>) = view.loadMovie(t)
                override fun onError(e: Throwable) {
                    view.showToast(e.toString())
                    view.cancleDialog()
                }
              override fun onCompleted() {
                  view.showToast("加载完成")
                  view.cancleDialog()
              }
          })
          this.compositeSubscription.add(disposable)
        }
        //取消订阅，释放资源
        override fun unsubscribe() {
            view.cancleDialog()
            compositeSubscription.clear()
        }
        companion object {
       //采用伴随对象
            //默认的值
            val defaultCompositeSubscription get() = CompositeSubscription()
        }
    }

**Activity中创建View和Presenter**:

class MovieListActvitiy : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_movielist) //创建View实例 var view=MovieListFragment.instance //创建Presenter实例 MovieListPresenter(view) //添加fragment supportFragmentManager.beginTransaction() .add(R.id.movielist_content_layout,view,MovieListFragment.Tag).commit() } }

最终项目结构目录如下：

![这里写图片描述][SouthEast 1]

### **4. 效果图如下**： ###

![image][]

#### **项目代码：[https://github.com/13767004362/KotlinMVPDemo][https_github.com_13767004362_KotlinMVPDemo]** ####

--------------------

**MVP架构相关的介绍**：

*  [Android Architecture Blueprints（架构蓝图）][Android Architecture Blueprints]
 *  [Android MVP架构][Android MVP]
 *  [ Android MVP架构（RxJava+SQLBrite+Retrofit+OkHttp+Glide）][Android MVP_RxJava_SQLBrite_Retrofit_OkHttp_Glide]
 *  [Android MVP架构（Volley+CursorLoader+ContentProvider）][Android MVP_Volley_CursorLoader_ContentProvider]

[Kotlin_AndroidStudio_3.0_2.x]: http://blog.csdn.net/hexingen/article/details/72621795
[Kotlin_Android_Volley_Gson]: http://blog.csdn.net/hexingen/article/details/72625383
[Kotlin_Kotlin Android Extensions]: http://blog.csdn.net/hexingen/article/details/72967615
[Kotlin_Glide v4 Generated API_Unresolved reference GlideApp]: http://blog.csdn.net/hexingen/article/details/72970807
[SouthEast]: /images/20220614/a5b94148e76945ba81aab94566a95ff7.png
[SouthEast 1]: /images/20220614/b36fa8f8c091480ab3ce45e915bdf8e4.png
[image]: /images/20220614/73d4b94f929848b4b82bf878a9552532.png
[https_github.com_13767004362_KotlinMVPDemo]: https://github.com/13767004362/KotlinMVPDemo
[Android Architecture Blueprints]: http://blog.csdn.net/hexingen/article/details/72057781
[Android MVP]: http://blog.csdn.net/hexingen/article/details/72058057
[Android MVP_RxJava_SQLBrite_Retrofit_OkHttp_Glide]: http://blog.csdn.net/hexingen/article/details/72420898
[Android MVP_Volley_CursorLoader_ContentProvider]: http://blog.csdn.net/hexingen/article/details/72082419