ReadHub项目Kotlin版转换指南(二、数据库和网络请求)
Android 开发中的 MVP 架构相信大家都已经熟悉，不熟悉的请右转 Google，ReadHub 项目从 Java 转换成 Kotlin 过程中，我们需要一套新的架构方式来实现（Kotlin 项目中没有使用 dagger2）。
base 为 MVP 架构的基础部分，user 为其具体使用过程。
base
BaseContract
interface BaseContract {
interface IView {
fun showLoading()
fun hideLoading()
}
interface IPresenter<V : IView> {
fun getView(): V
}
}
BaseContract 中定义了两个接口 IView 和 IPresenter，
IView 接口中定义了 Loading 的操作，使其可以在每个 View 中使用，如果你的项目中有一些需要在大多数 View 中用到的函数，也可定义在此接口中。
IPresenter 中声明一个泛型 V 继承自 IView，通过 getView 函数可以获取到该变量，用来回调 Model 中的结果给 View。
BaseActivity && BaseFragment
abstract class BaseActivity<P : BaseContract.IPresenter<*>> : AppCompatActivity(), BaseContract.IView {
private var mKProgressHUD: KProgressHUD? = null
protected lateinit var mPresenter: P
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val layoutId = getLayoutId()
setContentView(layoutId)
initView()
initData()
}
protected abstract fun getLayoutId(): Int
protected abstract fun initView()
protected abstract fun initData()
override fun showLoading() {
mKProgressHUD = KProgressHUD.create(this)
mKProgressHUD?.setStyle(KProgressHUD.Style.SPIN_INDETERMINATE)
?.setCancellable(true)
?.setAnimationSpeed(2)
?.setDimAmount(0.5f)
?.show()
}
override fun hideLoading() {
mKProgressHUD?.dismiss()
}
}
abstract class BaseFragment<P : BaseContract.IPresenter<*>> : Fragment(), BaseContract.IView {
private var mRootView: View? = null
private var mKProgressHUD: KProgressHUD? = null
protected lateinit var mPresenter: P
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
inflaterView(inflater, container)
return mRootView
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
initView(mRootView)
initData大专栏 ReadHub项目Kotlin版开发指南(三、MVP架构)n class="p">()
}
/**
* 设置View
*
* @param inflater
* @param container
*/
private fun inflaterView(inflater: LayoutInflater, @Nullable container: ViewGroup?) {
if (mRootView == null) {
mRootView = inflater.inflate(getLayoutId(), null)
}
}
protected abstract fun getLayoutId(): Int
protected abstract fun initView(view: View?)
protected abstract fun initData()
override fun showLoading() {
mKProgressHUD = KProgressHUD.create(activity)
mKProgressHUD?.setStyle(KProgressHUD.Style.SPIN_INDETERMINATE)
?.setCancellable(true)
?.setAnimationSpeed(2)
?.setDimAmount(0.5f)
?.show()
}
override fun hideLoading() {
mKProgressHUD?.dismiss()
}
}
BaseActivity 中声明泛型 P 继承自 BaseContract.IPresenter，变量 mPresenter 声明类型 P 并且延迟初始化（在子类中初始化）。
BaseActivity 继承 BaseContract.IView，重写回调方法，如 hideLoading、showLoading。
news
NewsContract
interface NewsContract {
interface View : BaseContract.IView {
fun updateTechNews(publishDate: String, newsMos: ArrayList<NewsMo>)
}
interface Presenter : BaseContract.IPresenter<View> {
fun getTechNews(publishDate: String)
}
}
NewsPresenter
class NewsPresenter(var mView: BaseContract.IView) : NewsContract.Presenter {
override fun getView(): NewsContract.View {
return mView as NewsContract.View
}
override fun getTechNews(publishDate: String) {
LogUtils.i("apiTachNews === ")
App.sInstance.apiService(ReadhubApiService::class.java)
?.apiTeachNews(publishDate, Constant.NEWS_PAGE_SIZE)
?.compose(RxSchedulers.io_main())
?.subscribe( {
getView()?.updateTechNews(publishDate, it.data!!)
}, {
LogUtils.e("apiTeachNews error == ${it}")
})
}
}
getView 获取 IView 对象的实现。
NewsFragment
class NewsFragment : BaseFragment<NewsPresenter>(), NewsContract.View {
override fun getLayoutId(): Int {
return R.layout.fragment_news
}
override fun initView(view: View?) {
}
override fun initData() {
mPresenter = NewsPresenter(this)
mPresenter?.getTechNews("")
}
override fun updateTechNews(publishDate: String, newsMos: ArrayList<NewsMo>) {}
}
构造 mPresenter 对象，获取 Model 中的数据。