MVP模式的认识

先来认识MVC：

 m ：model     模型（数据）
 v ：view      视图（显示）
 c ：control   控制（逻辑）

介于Android中显示的载体像Activity、Fragment既包含控制又包含视图，所以基本的Android应用可以做到的是m-vc
相比mvc，那么mvp中使用p（persenter）表示业务，接显示和模型处理数据也视图的关系

Model层

1、model层中的数据统一封装

public interface IModelCallback<T> {
    /**
     * 开始
     */
    void onStart();

    /**
     * 处理成功
     * @param data
     */
    void onSuccess(String data);

    /**
     * 处理失败
     * @param msg
     */
    void onFail(String msg);

    /**
     * 处理出现异常
     */
    void onError();

    /**
     * 处理完毕
     */
    void onComplete();
}

2、针对数据加载流程统一封装

public abstract class IModel<T> {
    protected Map<String,String> par;

    public IModel addPar(String key,String value){
        if (par==null){
            par = new HashMap<>();
        }
        par.put(key,value);
        return this;
    }

    //加载数据方法（管理线程，处理数据加载、转换）
    public abstract void execute(IModelCallback<T> callback);
}

View层

1、处理视图的共性部分

public interface IView {

    /**
     * 显示加载框
     */
    void showLoadingDialog();

    /**
     * 显示加载失败提醒
     * @param msg
     */
    void showFailMsg(String msg);

    /**
     * 显示加载异常提醒
     */
    void showErrorMsg();

    /**
     * 隐藏加载框
     */
    void hideLoadingDialog();
}

Persenter层

承上启下的作用

public class IPersenter<T extends IView> {
    protected T view;

    public void registView(T view){
        this.view = view;
    }

    public void unRegistView(){
        this.view = null;
    }

    public boolean isViewAvailable(){
        return view!=null;
    }
}

结合界面（Activity，Fragment）处理业务和视图关系

public class BaseActivity<T extends IPersenter> extends FragmentActivity implements IView {

    protected T persenter;
    private ProgressDialog dialog;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        persenter = createPersenter();
        persenter.registView(this);
    }

    //BaseActivity<T> BaseActivity<T,M,K>
    //LoginActivity<LoginPersonter> -->new LoginPersonter();
    private T createPersenter() {
        try {
            //父类中定义的Type
            Type type = getClass().getGenericSuperclass();
            if (type instanceof ParameterizedType) {
                ParameterizedType parameterizedType = (ParameterizedType) type;
                Type[] types = parameterizedType.getActualTypeArguments();
                Class<T> cls = (Class<T>) types[0];
                return cls.newInstance();
            }
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onDestroy() {
        persenter.unRegistView();
        super.onDestroy();
    }

    @Override
    public void showLoadingDialog() {
        if (null==dialog){
            dialog = ProgressDialog.show(this,"","数据加载中...");
        } else {
            dialog.show();
        }
    }

    @Override
    public void showFailMsg(String msg) {
        Toast.makeText(this,msg, Toast.LENGTH_LONG).show();
    }

    @Override
    public void showErrorMsg() {
        Toast.makeText(this,"加载异常",Toast.LENGTH_LONG).show();
    }

    @Override
    public void hideLoadingDialog() {
        dialog.dismiss();
    }
}

具体使用（个性化）

View:

public interface MyView1 extends IView {

   void showData(String data);
}

Model:

/**
 * 数据处理类
 */
public class MyModel1 extends IModel<String> {

    private Handler h = new Handler();

    @Override
    public void execute(final IModelCallback<String> callback) {
        //开始
        callback.onStart();
        new Thread() {
            @Override
            public void run() {
                try {
                    Thread.sleep(1000);
                    if (Integer.parseInt(par.get("num")) < 0) {
                        //处理失败，失败原因
                        h.post(new Runnable() {
                            @Override
                            public void run() {
                                callback.onFail("参数非法错误");
                            }
                        });
                    } else {
                        final String data = "加载了" + par.get("num") + "条数据";
                        //处理成功，加载数据
                        h.post(new Runnable() {
                            @Override
                            public void run() {
                                callback.onSuccess(data);
                            }
                        });
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                    //处理异常时
                    h.post(new Runnable() {
                        @Override
                        public void run() {
                            callback.onError();
                        }
                    });
                }
                //结束时，隐藏弹出框
                h.post(new Runnable() {
                    @Override
                    public void run() {
                        callback.onComplete();
                    }
                });
            }
        }.start();
    }
}

Persenter:

public class MyPersenter1 extends IPersenter<MyView1> {

    public void getData(int par) {
        MyModel1 model1 = new MyModel1();
        model1.addPar("num", "" + par);
        model1.execute(new IModelCallback() {
            @Override
            public void onStart() {
                if (isViewAvailable())
                    view.showLoadingDialog();
            }

            @Override
            public void onSuccess(String data) {
                if (isViewAvailable())
                    view.showData(data);
            }

            @Override
            public void onFail(String msg) {
                if (isViewAvailable())
                    view.showFailMsg(msg);
            }

            @Override
            public void onError() {
                if (isViewAvailable())
                    view.showErrorMsg();
            }

            @Override
            public void onComplete() {
                if (isViewAvailable())
                    view.hideLoadingDialog();
            }
        });
    }
}

界面使用：

public class MainActivity extends BaseActivity<MyPersenter1> implements View.OnClickListener,MyView1{

    private TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tv = findViewById(R.id.tv_result);
        tv.setOnClickListener(this);
    }

    int count = -1;
    @Override
    public void onClick(View v) {
        persenter.getData(count);
        count++;
    }

    @Override
    public void showData(String data) {
        tv.setText(data);
    }
}

MVP关系图