一个最最最简单的MVP框架Demo（下）

上一个Demo是为了让初识MVP的同学在总体上有一个了解，了解大概的运行流程，Demo很不规范和粗暴。

对于MVP框架，Google也有自己的Demo。下面我就按照Google的代码规范一下上次的那个例子。GoogleMVPDemo

BaseView

public interface BaseView<T> {

    void setPresenter(T presenter);

}

BasePresenter

public interface BasePresenter<T> {

    void start();

}

Contarct(契约类)
Google的Demo中多了一个契约类，并且将所需要的接口都写在里面，方便开发者查看V和P中的方法有哪些。

public interface Contarct {

    interface View extends BaseView<Presenter> {

        void showLoading();

        void hideLoading();

        void setListItem(List<String> data);

        void failed();

        void showMessage(String message);
    }
    interface Presenter extends BasePresenter {
        void itemclick(int position);
    }
}

OK！接下来就是MVP三部分的实现了。

M

这次偷懒直接将数据获取写在了P中。所以没有用到。

P

public class MvpPresenter implements Contarct.Presenter {

    private Contarct.View MvpView;

 //在Google_MVP_Demo中使用了Fragemnt所以初始化P对象是在Activity中
    public MvpPresenter(Contarct.View mvpView) {
        MvpView = mvpView;
        MvpView.setPresenter(this);
    }

//在Google_MVP_Demo中是在Fragment中开始执行start操作
    @Override
    public void start() {
        MvpView.showLoading();
        GetData();//获取数据
    }

    //模拟数据处理
    List data = new ArrayList();

    private void GetData() {
        Observable.create(new ObservableOnSubscribe<List<String>>() {
            @Override
            public void subscribe(@NonNull ObservableEmitter<List<String>> e) throws Exception {
                for (int i = 0; i < 50; i++) {
                    data.add(i + "items");
                }
                e.onNext(data);
            }
        }).subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Observer<List<String>>() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(List<String> strings) {
                        MvpView.hideLoading();
                        MvpView.setListItem(data);//数据获取成功
                    }

                    @Override
                    public void onError(Throwable e) {
                        MvpView.failed();
                    }

                    @Override
                    public void onComplete() {

                    }
                });
    }

    @Override
    public void itemclick(int position) {
        MvpView.showMessage("点击了item" + position);
    }

V

一个Activity展示一个列表，在Google_MVP_Demo中是Fragment。

public class MvpActivity extends AppCompatActivity implements Contarct.View, AdapterView.OnItemClickListener {

    private ListView mvpListView;
    private Contarct.Presenter mPresenter;
    private ProgressBar pb;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_mvp);
        mvpListView = (ListView) findViewById(R.id.mvp_listview);
        mvpListView.setOnItemClickListener(this);
        pb = (ProgressBar) findViewById(R.id.mvp_loading);

        new MvpPresenter(this);
        mPresenter.start();
    }

    @Override
    public void showLoading() {
        pb.setVisibility(View.VISIBLE);
    }

    @Override
    public void hideLoading() {
        pb.setVisibility(View.GONE);
    }

    @Override
    public void setListItem(List<String> data) {
        ArrayAdapter adapter = new ArrayAdapter(MvpActivity.this, android.R.layout.simple_list_item_1, data);
        mvpListView.setAdapter(adapter);
    }

    @Override
    public void failed() {
        Toast.makeText(MvpActivity.this, "加载失败", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void showMessage(String message) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        mPresenter.itemclick(position);
    }

    @Override
    public void setPresenter(Contarct.Presenter presenter) {
        this.mPresenter = presenter;
    }

Demo链接（其实就是上次那个- -）