前言：Android開發(fā)中有很多的設(shè)計(jì)模式鹿寻，MVP模式無(wú)疑是現(xiàn)在最流行的模式之一。MVP模式有效的降低了項(xiàng)目的復(fù)雜性及耦合性，view與model間完全解耦，通過(guò)presenter作為中間的連接紐帶丢胚，降低了view的復(fù)雜性及view與model耦合程度，使的項(xiàng)目邏輯更加清晰受扳，方便后期的修改與維護(hù)携龟。

MVP：Model--View--Presenter

model：用于數(shù)據(jù)的處理，如請(qǐng)求網(wǎng)絡(luò)數(shù)據(jù)等

view：用于將presenter傳遞的數(shù)據(jù)在UI中展示

presenter：將model獲取的數(shù)據(jù)傳遞給view勘高，是view與model聯(lián)系的中間橋梁

注：文中有用到Retrofit2+Rxjava2+Okhttp3實(shí)現(xiàn)網(wǎng)絡(luò)數(shù)據(jù)請(qǐng)求相關(guān)的知識(shí)峡蟋，這一篇文章 Android網(wǎng)絡(luò)請(qǐng)求Retrofit2+Rxjava2+Okhttp3的簡(jiǎn)單封裝中有詳細(xì)介紹。

1.Model

（1）定義model基類接口

/**  
* Created by ruancw on 2018/5/22. 
* model接口基類 
*/   
public interface IBaseModel {
    //獲取Rxjava的disposable
    <T>Disposable getObservable(Observable<HttpResponse<T>> observable, String tag);
    //網(wǎng)絡(luò)請(qǐng)求接口回調(diào)
    interface IOnRequestListener<T>{
        void onRequestSuccess(HttpResponse<T> tHttpResponse, String tag);
         void onRequestFail(Throwable throwable);
    }
}

（2）定義model實(shí)現(xiàn)類

/**  
* Created by ruancw on 2018/5/22. 
* 通用model實(shí)現(xiàn)類 
*/   
public class CommonModelImpl implements IBaseModel {
    private IOnRequestListener onRequestListener;   
    public CommonModelImpl(IOnRequestListener onRequestListener) {
        this.onRequestListener = onRequestListener;
    }

    @Override
    public <T> Disposable getObservable(Observable<HttpResponse<T>> observable, String tag) {
        return DisposableUtils.getDisposable(observable,tag,onRequestListener);
    }
}

2.View

定義view接口類

/**  
* Created by ruancw on 2018/5/22. 
* view基類接口 
*/   
public interface IBaseView {
    //顯示默認(rèn)的進(jìn)度框
    void showProgress();
    //顯示可設(shè)置提示信息的進(jìn)度框
    void showProgress(String message);
    //隱藏進(jìn)度框
    void hideProgress();
    //網(wǎng)絡(luò)請(qǐng)求數(shù)據(jù)成功后返回?cái)?shù)據(jù)的方法
    void onSuccess(HttpResponse httpResponse, String tag);
    //網(wǎng)絡(luò)請(qǐng)求失敗的方法
    void onFailed(Throwable throwable); 
}

3.Presenter

（1）定義presenter的基類

/**  
* Created by ruancw on 2018/5/22. 
* presenter基類 
*/   
public class BasePresenter implements IBaseModel.IOnRequestListener {
    //view接口
    protected IBaseView mView;
    //model接口實(shí)現(xiàn)類
    protected CommonModelImpl mModel;
    //Rxjava中的類
    private CompositeDisposable mCompositeDisposable;    
    /**  
    * 綁定view 
    * @param mView   
    */   
    public void attach(IBaseView mView){
        this.mView=mView;
        mModel=new CommonModelImpl(this);
    }

    /**  
    * 解綁view 
    */  
    public void detach(){
        if (mView!=null){
            mView=null;
        }
    }

    /**  
    * 反注冊(cè)rxjava 
    */  
    public void unSubscribe(){
        if (mCompositeDisposable != null) {
            mCompositeDisposable.dispose();
        }
    }

    /**  
    * 注冊(cè)rxjava 
    * @param disposable   
    */   
    public void addSubscription(Disposable disposable) {
        //rxjava進(jìn)行注冊(cè)
        if (mCompositeDisposable == null) {
            mCompositeDisposable= new CompositeDisposable();
        }
        mCompositeDisposable.add(disposable);
    }

    @Override
     public void onRequestSuccess(HttpResponse httpResponse, String tag) {
        if (mView!=null){
            mView.hideProgress();
            mView.onSuccess(httpResponse,tag);
        }
    }

    @Override
     public void onRequestFail(Throwable throwable) {
        if (mView!=null){
            mView.hideProgress();
            mView.onFailed(throwable);
        }
    }
}

（2）繼承基類BasePresenter（以登錄為例）

/**  
* Created by ruancw on 2018/5/23. 
* 登錄的presenter實(shí)現(xiàn)類 
*/   
public class LoginPresenterImpl extends BasePresenter {
    public void login(String url, LinkedHashMap<String, String> paramsMap,String tag){
        mView.showProgress("正在登錄");
        addSubscription(mModel.getObservable(HttpApiService.getInstance().getRemoteData(url,paramsMap),tag));
    }
}

注：直接定義的LoginPresenter的實(shí)現(xiàn)類华望，沒有定義ILoginPresenter接口

4.模塊中使用

（1）定義Activity基類

public abstract class BaseMvpActivity<B extends BasePresenter> extends BaseActivity {

    public B mPresenter;    
    @Override
    protected void beforeSetContentView() {
        mPresenter=initPresenter();
        mPresenter.attach(this);
    }

    protected abstract B initPresenter();    
    @Override
    protected void onDestroy() {
        mPresenter.detach();
        //mPresenter.unSubscribe();
        super.onDestroy();
    }
}

（2）LoginActivity繼承BaseMvpActivity

public class LoginActivity extends BaseMvpActivity<LoginPresenterImpl> {
    @BindView(R.id.btn_login)
    Button btnLogin;
    @BindView(R.id.et_account)
    ClearEditText etAccount;
    @BindView(R.id.et_password)
    PasswordView etPassword;
    private int userType=1;
    private UserBean userBean;
    private boolean autoLogin;      @Override
    protected boolean hasHeadTitle() {
        return false;
    }

    @Override
    protected LoginPresenterImpl initPresenter() {
        return new LoginPresenterImpl();
    }  

    @Override
    protected int getLayoutId() {
        return R.layout.activity_login;
    }

    @Override
    protected void initView() {
        //獲取上一次填寫的用手機(jī)號(hào)與密碼
        userBean=SharePreferencesUtil.getInstance().getUserBean();
        if (this.getIntent() != null && this.getIntent().getExtras() != null && this.getIntent().getExtras().containsKey("username")) {
            String username = this.getIntent().getExtras().getString("username");
            etAccount.setText(username);
        } else {
            if (userBean != null) {
                etAccount.setText(userBean.getAccount());
                etPassword.setContent(userBean.getPassword());
            }
        }
        //判斷是否是自動(dòng)登錄
        autoLogin=SharePreferencesUtil.getInstance().getBoolean("AUTO_LOGIN");
        if (autoLogin){
            //自動(dòng)登錄
            login();
        }
    }

    /**  
    * 登錄的方法 
    */  
    private void login() {
        etPassword.clearFocus();
        //系統(tǒng)的輸入管理器
        InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.showSoftInput(etPassword, InputMethodManager.SHOW_FORCED);
        imm.hideSoftInputFromWindow(etPassword.getWindowToken(), 0);
       if (TextUtils.isEmpty(etAccount.getText().toString().trim())) {
            UIUtil.toast("手機(jī)號(hào)不能為空");
       } else if (TextUtils.isEmpty(etPassword.getContent().trim())) {
            UIUtil.toast("密碼不能為空");
       } else {
            LinkedHashMap<String, String> paramsMap = new LinkedHashMap<>();
            paramsMap.put("loginName", etAccount.getText().toString().trim());
            paramsMap.put("password", etPassword.getContent().trim());
            paramsMap.put("userType", userType + "");
            mPresenter.login(ApiConstant.LOGIN, paramsMap, "tag");
      }
    }

    @OnClick(R.id.btn_login)
    public void onViewClicked() {
        //點(diǎn)擊的動(dòng)畫效果
        CommonUtil.animateClickView(btnLogin, new CommonUtil.ClickAnimation() {
            @Override
            public void onClick(View v) {
                login();
            }
        });    
    }

    @Override
    public void onSuccess(HttpResponse httpResponse, String tag) {
        int code = httpResponse.getStatus();
        Log.i("rcw", "httpResponse=" + httpResponse);
        Log.i("rcw", "code=" + httpResponse.getStatus());
        Log.i("rcw", "data=" + httpResponse.getData());
        if (code == 200) {
            //存儲(chǔ)賬號(hào)和密碼
            userBean=new UserBean();
            userBean.setAccount(etAccount.getText().toString().trim());
            userBean.setPassword(etPassword.getContent().trim());
            userBean.setUsertype(userType);
            SharePreferencesUtil.getInstance().saveUserBean(userBean);  
            //處理返回的data數(shù)據(jù)  
            String datas = new Gson().toJson(httpResponse.getData());
            LoginBean loginBean = new Gson().fromJson(datas, LoginBean.class);
            SharePreferencesUtil.getInstance().saveLoginBean(loginBean);
            Log.i("rcw", "getDeptName=" + loginBean.getDeptName());
            startActivity(new Intent(this, MainActivity.class));
            finish();
            UIUtil.toast("登錄成功");
        } else if (code == 402) {
            exitToLogin(this);
        } else {
            UIUtil.toast(httpResponse.getMessage());
    }    

 }

總結(jié)：MVP模式使得View與Model間不能直接交互层亿，通過(guò)中間紐帶Presenter實(shí)現(xiàn)間接聯(lián)系，降低了View與Model間的耦合立美。MVP模式雖好，但如果項(xiàng)目頁(yè)面相對(duì)簡(jiǎn)單方灾，可以直接使用MVC模式實(shí)現(xiàn)建蹄。

如有任何問(wèn)題碌更，歡迎評(píng)論及留言，不勝感激洞慎，謝謝Ｍ吹ァ！劲腿！