MVP与MVP+Dagger2的使用及比较

最新推荐文章于 2019-02-28 20:51:53 发布

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本文详细介绍了MVP模式及其与Dagger2结合的应用方式，包括Presenter、Model、View各层的具体实现，并对比了两种模式的优劣。

MVP初体验与MVP引入Dagger2初体验

Mvp模式理解
一、分析Presenter层
1.1 Presenter 注入实现接口IView的Acticity

public class MainActivity extends AppCompatActivity implements View.OnClickListener, IUserLoginView {
    ...
    private void loadData() {
        mLoginPresenter = new LoginPresenter();
        mLoginPresenter.attachView(this);
    } 
    ...
}

1.2 Presenter 构造中创建Model层

public class LoginPresenter extends BasePresenter<IUserLoginView> {
    private LoginTasksRepository mLoginTasksRepository;

    public LoginPresenter() {
        mLoginTasksRepository = new LoginTasksRepository();
    }

    Login();--
}

1.3 Presenter 中处理当前Activity中的事件，如登陆事件Login
下图分析：调用model层方法Login，处理网络请求，返回结果，view层响应事件

public void login(String loginReq){
    mLoginTasksRepository.login(loginReq, new LoginTaskDataSource.NetTasksCallback() {
        @Override
        public void onSuccess(LoginResponse loginResponse) {
            mvpView.hideLoading();
            mvpView.onSuccess(loginResponse);
        }

        @Override
        public void onFailure(String errorMsg) {

        }
    });
}

public abstract class BasePresenter<V extends IMvpView> implements Presenter<V> {
    protected V mvpView;

    public void attachView(V view){
        mvpView = view;
    }

    @Override
    public void detachView(V view) {
        mvpView = null;
    }

    @Override
    public String getName() {
        return mvpView.getClass().getSimpleName();
    }
}

public interface Presenter<V> {
    void attachView(V view);

    void detachView(V view);

    String getName();
}

二、分析Model层
2.1 网络请求或数据库存储

public interface LoginTaskDataSource {

    void saveLoginResponse(LoginResponse loginResponse);

    void login(String loginReq, NetTasksCallback callback);

    interface NetTasksCallback{
        void onSuccess(LoginResponse loginResponse);
        void onFailure(String errorMsg);
    }
}


public class LoginTasksRepository implements LoginTaskDataSource {
    @Override
    public void saveLoginResponse(LoginResponse loginResponse) {

    }

    @Override
    public void login(String loginReq, NetTasksCallback callback) {
        //开启网络请求

        //成功后
        LoginResponse loginResponse = new LoginResponse();
        loginResponse.setResultInfo(loginReq+"===登录成功");
        loginResponse.setResultCode("0");
        callback.onSuccess(loginResponse);
    }
}

三、分析View层
3.1 分析Activity中的具体方法，封装进接口，在loadData中注入。点击事件调用P层

public interface IMvpView {
    void onError(String errorMsg, String code);

    void onSuccess(LoginResponse loginResponse);

    void showLoading();

    void hideLoading();
}

public interface IUserLoginView extends IMvpView{
    void clearEditContent();
}

public class MainActivity extends AppCompatActivity implements View.OnClickListener, IUserLoginView {

    private EditText mUsername;
    private EditText mPassword;
    private Button mLogin;
    private LoginPresenter mLoginPresenter;

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

        initView();
        loadData();
    }

    private void initView() {
        mUsername = (EditText) findViewById(R.id.username);
        mPassword = (EditText) findViewById(R.id.password);
        mLogin = (Button) findViewById(R.id.login);

        mLogin.setOnClickListener(this);
    }

    private void loadData() {
        mLoginPresenter = new LoginPresenter();
        mLoginPresenter.attachView(this);
    }

    @Override
    public void onClick(View v) {
        mLoginPresenter.login(mUsername.getText().toString() + "-" + mPassword.getText().toString());
    }

    @Override
    public void clearEditContent() {
        mUsername.setText("");
        mPassword.setText("");
    }

    @Override
    public void onError(String errorMsg, String code) {

    }

    @Override
    public void onSuccess(LoginResponse loginResponse) {
        Toast.makeText(this, loginResponse.getResultInfo(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void showLoading() {

    }

    @Override
    public void hideLoading() {

    }

    @Override
    protected void onDestroy() {
        mLoginPresenter.detachView(this);
        super.onDestroy();
    }
}

3.2 当Destory时，需注销GC链，避免内存泄露

Mvp+ Dagger2模式理解

依赖

apply plugin: 'com.neenbedankt.android-apt'
dependencies：
apt 'com.google.dagger:dagger-compiler:2.2'
compile 'com.google.dagger:dagger:2.2'

一、分析Presenter层
分析：一样也是P连接 M 和 V

public class MainPresenter implements MainContract.IPresenter {
    private MainContract.IModel model;
    private MainContract.IView view;

    public MainPresenter(MainContract.IView view) {
        this.view = view;
        this.model = new MainModel();
    }

    @Override
    public void onButtonClicked(Context context, String text) {
        model.onButtonClicked(context,text);
    }
}

二、mvp接口类

public class MainContract {

    interface IView{
        void onButtonClicked(String text);
    }

    interface  IModel{
        void onButtonClicked(Context context,String text);
    }

    interface IPresenter{
        void onButtonClicked(Context context,String text);
    }
}

三、Model层

public class MainModel implements MainContract.IModel {
    @Override
    public void onButtonClicked(Context context, String text) {
        Toast.makeText(context,text,Toast.LENGTH_SHORT).show();
    }
}

四、注入接口

@Singleton
@Component(modules = MainModule.class)
public interface MainComponent {
    void inject(MainActivity activity);
}

五、引入dagger2模式
分析：对应第六点的注入过程，给V提供P层对象

@Module
public class MainModule {
    MainPresenter mPresenter;

    public MainModule(MainActivity activity){
        mPresenter = new MainPresenter(activity);
    }
    @Provides
    @Singleton
    MainPresenter providersMainPresenter(){
        return mPresenter;
    }
}

六、View
分析：实现IView 接口，DaggerMainComponent注入（相对于MVP少了新建P层，调P层方法注入），点击调P层

public class MainActivity extends AppCompatActivity implements MainContract.IView {
    @Inject
    MainPresenter presenter;

    @InjectView(R.id.btn)
    Button mBtn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.inject(this);
        //这步之前需要rebuild一下
        DaggerMainComponent.builder().mainModule(new MainModule(MainActivity.this)).build().inject(this);
    }

    @Override
    public void onButtonClicked(String text) {
        presenter.onButtonClicked(this,text);
    }

    @OnClick(R.id.btn)
    public void onClick() {
        onButtonClicked("Button Clicked!!!");
    }
}