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Android mvp分层架构优雅写代码

开发进阶 loading 2190浏览 0评论

背景

看了好多android技术博客,写android分层架构的博客越来越多,有mvc、mvp、mvvm、clean等各式各样的,而mvp异常火热,然而每个人对mvp的定义又是不同,写法自然也是千紫万红。

目的

写一个实用分层清晰的mvp架构

主题

mvp无非 model(数据)、view(界面)、presenter(逻辑)。model对应本地持久化或远程服务端数据,而在笔者看来其实就是对应一个bean对象,然而这个bean对象由远程服务器或本地持久化而得到,因而此层需封装网络请求和本地持久化;view对应activity、fragment以及它们对应的xml布局文件,这层只负责做ui显示;presenter对应逻辑处理层,所做的事情很多,包括网络请求操作、读取缓存数据操作、算法计算等等。

接下来写代码来分析笔者认为优雅的mvp分层架构,开始看一下项目分组,如下图所示:

从上图我们看到module下有四个分组,分别对应:contract、model、presenter、views。相信大部分童鞋对contract有点疑惑,这个分组是干啥用的呢?contract是作为契约,目的是将presenter、views等接口集中关联起来,便于统一管理。

打开契约分组,我们看到四个接口和一个类,分别为IActivityLifeCycle(Activity生命周期接口类)、IBaseActivity(Activity接口基类 界面层的)、IBaseFragment(Fragment接口基类 界面层的)、IBasePresenter(逻辑层基类 逻辑层的)、UserInfoContract(用户信息契约类,关联view层与presenter层接口,方便统一管理)。

IActivityLifeCycle代码如下:

/**
 * @className: IActivityLifeCycle
 * @classDescription: 生命周期接口(为了实现Activity UI层生命周期映射到逻辑层)
 * @author: leibing
 * @createTime: 2016/8/11
 */
public interface IActivityLifeCycle {
    void onCreate();
    void onRestart();
    void onStart();
    void onResume();
    void onPause();
    void onStop();
    void onDestroy();
}

IActivityLifeCycle 作为一个activity生命周期接口,为了将activity生命周期映射到对应presenter层,便于逻辑层能更好的处理跟activity生命周期有关的事件。

IBaseActivity代码如下:

package com.ym.mvpdemo.module.contract;

/**
 * @className: IBaseActivity
 * @classDescription: activity接口基类
 * @author: leibing
 * @createTime: 2016/8/11
 */
public interface IBaseActivity<T> {
    // 设置逻辑
    void setPresenter(T mIActivityPresenter);
    // 设置生命周期
    void setILifeCycle(IActivityLifeCycle mIActivityLifeCycle);
}

IBaseActivity作为一个view层的activity接口基类,主要是设置逻辑层和设置生命周期,将逻辑层与界面层绑定起来,将activity生命周期映射到逻辑层去。

IBaseFragment代码如下:

package com.ym.mvpdemo.module.contract;

/**
 * @className:IBaseFragment
 * @classDescription:Fragment接口基类
 * @author: leibing
 * @createTime: 2016/8/12
 */
public interface IBaseFragment<T> {
    // 设置逻辑
    void setPresenter(T mIFragmentPresenter);
}

IBaseFragment作为一个view层的fragment接口基类,主要是设置逻辑层,将逻辑层与界面层绑定起来。

IBasePresenter代码如下:

package com.ym.mvpdemo.module.contract;

/**
 * @className: IBasePresenter
 * @classDescription: 逻辑层基类
 * @author: leibing
 * @createTime: 2016/8/11
 */
public interface IBasePresenter {
    // 逻辑层开始执行方法
    void start();
}

IBasePresenter作为一个逻辑层基类,主要做界面层与逻辑层绑定之后,逻辑层初始化工作。

UserInfoContract比较重要,大家仔细看看,代码如下:

package com.ym.mvpdemo.module.contract;

import com.ym.mvpdemo.module.model.UserInfoModel;

/**
 * @className: UserInfoContract
 * @classDescription: 用户信息契约类
 * @author: leibing
 * @createTime: 2016/8/11
 */
public class UserInfoContract {
    /**
     * 用户信息activity中用于更新UI的方法集合
     * @interfaceName: IUserInfoActivity
     * @interfaceDescription: View接口
     * @author: leibing
     * @createTime: 2016/08/23
     */
    public interface IUserInfoActivity extends IBaseActivity<IUserInfoActivityPresenter> {
        void showLoading();//展示加载框
        void dismissLoading();//取消加载框展示
        void showUserInfo(UserInfoModel userInfoModel);//将网络请求得到的用户信息回调
        String loadUserId();//假设接口请求需要一个userId
    }

    /**
     * 用户信息Fragment中用于更新UI的方法集合
     * @interfaceName: IFragment
     * @interfaceDescription: Fragment接口
     * @author: leibing
     * @createTime: 2016/08/23
     */
    public interface IUserInfoFragment extends IBaseFragment<IUserInfoFragmentPresenter> {
        void showData(); // 假定显示数据
    }

    /**
     * 用户信息activity逻辑层需要使用的方法集合
     * @interfaceName: IUserInfoActivityPresenter
     * @interfaceDescription: 用户信息Activity逻辑层接口
     * @author: leibing
     * @createTime: 2016/08/23
     */
    public interface IUserInfoActivityPresenter extends IBasePresenter {
        void loadUserInfo();
    }

    /**
     * 用户信息Fragment逻辑层需要使用的方法集合
     * @interfaceName: IUserInfoFragmentPresenter
     * @interfaceDescription: 用户信息Fragment逻辑层接口
     * @author: leibing
     * @createTime: 2016/08/23
     */
    public interface IUserInfoFragmentPresenter extends IBasePresenter {
        void loadData();
    }
}

UserInfoContract作为一个契约类,将界面层与逻辑层接口进行集中管理,便于提高接口可读性。

契约分组分析完了,然后我们再看model,model结构图如下所示:

至此,我们看到httprequest、data两个分组,这两分组分别对应网络请求封装和数据持久化封装,这两块封装看个人了,没有一个绝对的方案,我们还看到一个UserInfoModel,这里我就先放外面了,没放httprequest和data里面去了,这里具体封装具体放对应的位置,网络请求封装可以参考基于Retrofit、OkHttp、Gson封装通用网络框架、持久化数据封装可以参考android基于xml实现的对象缓存方案

接下来我们分析View层,View分组如下图所示:

view分组就一个activity和一个fragment,其实这层很简单,主要做更新ui的工作,代码结构也比较清晰,笔者在activity里面将对应生命周期映射到了其逻辑层上面去了,这样省去了在生命周期上面 view层往逻辑层写方法的麻烦。

activity代码如下:

package com.ym.mvpdemo.module.views.userinfo;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import android.widget.Toast;
import com.ym.mvpdemo.R;
import com.ym.mvpdemo.adapter.ViewpagerAdapter;
import com.ym.mvpdemo.module.contract.IActivityLifeCycle;
import com.ym.mvpdemo.module.contract.UserInfoContract;
import com.ym.mvpdemo.module.model.UserInfoModel;
import com.ym.mvpdemo.module.presenter.userinfo.UserInfoActivityPresenter;
import java.util.ArrayList;
import java.util.List;
import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

/**
 * @className: UserInfoActivity
 * @classDescription: UI层(Activity)
 * @author: leibing
 * @createTime: 2016/8/11
 */
public class UserInfoActivity extends AppCompatActivity implements UserInfoContract.IUserInfoActivity{
    // 切换Tab常量
    public final static int HOME_INDEX = 0;
    public final static int CZH_INDEX = 1;
    public final static int ME_INDEX = 2;
    // Activity逻辑层接口
    private UserInfoContract.IUserInfoActivityPresenter mIActivityPresenter;
    // 生命周期接口
    private IActivityLifeCycle mIActivityLifeCycle;
    // Fragment
    private UserInfoFragment mHomeFragment;
    private UserInfoFragment mCzhFragment;
    private UserInfoFragment mMineFragment;
    // Fragement列表
    private List<Fragment> mFragmentList;
    // 标题列表
    private List<String> mTitleList;

    @BindView(R.id.tv_name) TextView nameTv;
    @BindView(R.id.tv_age) TextView ageTv;
    @BindView(R.id.tv_address) TextView addressTv;
    @BindView(R.id.vpg_main) ViewPager mainPager;
    @BindView(R.id.tv_main_home) TextView mainHomeTv;
    @BindView(R.id.tv_main_czh) TextView mainCzhTv;
    @BindView(R.id.tv_main_me) TextView mainMeTv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 绑定ButterKnife
        ButterKnife.bind(this);
        // 初始化list
        initList();
        // 初始化Fragment
        initFragment();
        // 初始化逻辑
        new UserInfoActivityPresenter(this);
        mIActivityPresenter.start();
        // View映射onCreate生命周期到Presenter
        mIActivityLifeCycle.onCreate();
    }

    /**
     * 初始化列表
     * @author leibing
     * @createTime 2016/8/11
     * @lastModify 2016/8/11
     * @return
     */
    private void initList() {
        mFragmentList = new ArrayList<>();
        mTitleList = new ArrayList<>();
    }

    /**
     * 初始化Fragment
     * @author leibing
     * @createTime 2016/8/11
     * @lastModify 2016/8/11
     * @param
     * @return
     */
    private void initFragment() {
        // 首页
        mHomeFragment = new UserInfoFragment();
        Bundle bundle = new Bundle();
        bundle.putSerializable(UserInfoFragment.PAGE_INDEX, HOME_INDEX);
        mHomeFragment.setArguments(bundle);
        mFragmentList.add(mHomeFragment);

        // 车智汇
        mCzhFragment = new UserInfoFragment();
        bundle = new Bundle();
        bundle.putSerializable(UserInfoFragment.PAGE_INDEX, CZH_INDEX);
        mCzhFragment.setArguments(bundle);
        mFragmentList.add(mCzhFragment);

        // 我的
        mMineFragment = new UserInfoFragment();
        bundle = new Bundle();
        bundle.putSerializable(UserInfoFragment.PAGE_INDEX, ME_INDEX);
        mMineFragment.setArguments(bundle);
        mFragmentList.add(mMineFragment);

        // ViewPager适配
        ViewpagerAdapter mAdapter = new ViewpagerAdapter(
                getSupportFragmentManager(), mFragmentList, mTitleList);
        mainPager.setAdapter(mAdapter);
        mainPager.setOffscreenPageLimit(3);
        mainPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }

            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                if (positionOffset == 0.0)
                    switchTab(position);
            }
        });
        mainPager.setCurrentItem(0);
    }

    /**
     * 切换Tab页
     * @author leibing
     * @createTime 2016/5/6
     * @lastModify 2016/5/6
     * @param index
     * @return
     */
    private void switchTab(int index){
        switch (index){
            case HOME_INDEX:
                mainHomeTv.setTextColor(getResources().getColor(R.color.main_home_text_blue));
                mainCzhTv.setTextColor(getResources().getColor(R.color.main_home_text_gray));
                mainMeTv.setTextColor(getResources().getColor(R.color.main_home_text_gray));
                break;
            case CZH_INDEX:
                mainHomeTv.setTextColor(getResources().getColor(R.color.main_home_text_gray));
                mainCzhTv.setTextColor(getResources().getColor(R.color.main_home_text_blue));
                mainMeTv.setTextColor(getResources().getColor(R.color.main_home_text_gray));
                break;
            case ME_INDEX:
                mainHomeTv.setTextColor(getResources().getColor(R.color.main_home_text_gray));
                mainCzhTv.setTextColor(getResources().getColor(R.color.main_home_text_gray));
                mainMeTv.setTextColor(getResources().getColor(R.color.main_home_text_blue));
                break;
        }
    }

    @Override
    protected void onRestart() {
        // View映射onRestart生命周期到Presenter
        mIActivityLifeCycle.onRestart();
        super.onRestart();
    }

    @Override
    protected void onStart() {
        super.onStart();
        // View映射onStart生命周期到Presenter
        mIActivityLifeCycle.onStart();
    }

    @Override
    protected void onResume() {
        super.onResume();
        // View映射onResume生命周期到Presenter
        mIActivityLifeCycle.onResume();
    }

    @Override
    protected void onPause() {
        // View映射onPause生命周期到Presenter
        mIActivityLifeCycle.onPause();
        super.onPause();
    }

    @Override
    protected void onStop() {
        // View映射onStop生命周期到Presenter
        mIActivityLifeCycle.onStop();
        super.onStop();
    }

    @Override
    protected void onDestroy() {
        // View映射onDestroy生命周期到Presenter
        mIActivityLifeCycle.onDestroy();
        super.onDestroy();
    }

    @Override
    public void showLoading() {
        Toast.makeText(this, "正在加载", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void dismissLoading() {
        Toast.makeText(this, "加载完成", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void showUserInfo(UserInfoModel userInfoModel) {
        if (userInfoModel != null) {
            nameTv.setText(userInfoModel.getName());
            ageTv.setText(String.valueOf(userInfoModel.getAge()));
            addressTv.setText(userInfoModel.getAddress());
        }
    }

    @Override
    public String loadUserId() {
        return "1000";//假设需要查询的用户信息的userId是1000
    }

    @Override
    public void setPresenter(UserInfoContract.IUserInfoActivityPresenter mIActivityPresenter) {
        this.mIActivityPresenter = mIActivityPresenter;
    }

    public void setILifeCycle(IActivityLifeCycle mIActivityLifeCycle) {
        this.mIActivityLifeCycle = mIActivityLifeCycle;
    }

    @OnClick(R.id.ly_main_home) void mainOnClick() {
        mainPager.setCurrentItem(HOME_INDEX, false);
    }

    @OnClick(R.id.ly_main_czh) void czhOnClick() {
        mainPager.setCurrentItem(CZH_INDEX, false);
    }

    @OnClick(R.id.ly_main_me) void meOnClick() {
        mainPager.setCurrentItem(ME_INDEX, false);
    }
}

fragment代码如下:

package com.ym.mvpdemo.module.views.userinfo;

import android.app.Activity;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import com.ym.mvpdemo.R;
import com.ym.mvpdemo.module.contract.UserInfoContract;
import com.ym.mvpdemo.module.presenter.userinfo.UserInfoFragmentPresenter;
import butterknife.BindView;
import butterknife.ButterKnife;

/**
 * @className: UserInfoFragment
 * @classDescription: Ui层(IFragment)
 * @author: leibing
 * @createTime: 2016/8/11
 */
public class UserInfoFragment extends Fragment implements UserInfoContract.IUserInfoFragment {
    // 页面常量
    public final static String PAGE_INDEX = "page_index";
    // 页面数字
    private int pageIndex;
    // UI回调
    private UserInfoContract.IUserInfoFragmentPresenter mIFragmentPresenter;
    // 判断是否当前Fragment
    private boolean isVisibleToUser = false;

    @BindView(R.id.tv_fgm)
    TextView fgmTv;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        pageIndex = (int) getArguments().getSerializable(PAGE_INDEX) + 1;
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_main, null);
        // 绑定ButterKnife
        ButterKnife.bind(this, view);

        fgmTv.setText("第"+ pageIndex + "页");
        if (isVisibleToUser) {
            new UserInfoFragmentPresenter(this);
            mIFragmentPresenter.start();
        }
        return view;
    }

    @Override
    public void showData() {
        Toast.makeText(getActivity(), "这是第" + pageIndex + "个页面", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void setPresenter(UserInfoContract.IUserInfoFragmentPresenter mIFragmentPresenter) {
        this.mIFragmentPresenter = mIFragmentPresenter;
    }

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        this.isVisibleToUser = isVisibleToUser;
    }
}

view层分析完后,接下来我们来分析压轴戏:presenter(逻辑层),逻辑层分组情况如下图所示:

我们可以看到逻辑层分组里面包含一个activity逻辑层类、fragment逻辑层类。

接下来我们看下activity逻辑层类,代码如下:

package com.ym.mvpdemo.module.presenter.userinfo;

import android.os.Handler;
import com.ym.mvpdemo.module.contract.IActivityLifeCycle;
import com.ym.mvpdemo.module.contract.UserInfoContract;
import com.ym.mvpdemo.module.model.UserInfoModel;

/**
 * @className: UserInfoActivityPresenter
 * @classDescription: 用户信息activity逻辑层
 * @author: leibing
 * @createTime: 2016/8/11
 */
public class UserInfoActivityPresenter implements UserInfoContract.IUserInfoActivityPresenter, IActivityLifeCycle {
    // 用户信息activity接口
    private UserInfoContract.IUserInfoActivity mIUserInfoActivity;

    /**
     * 构造函数
     * @author leibing
     * @createTime 2016/08/23
     * @lastModify 2016/08/23
     * @param mIUserInfoActivity 用户信息activity接口
     * @return
     */
    public UserInfoActivityPresenter(UserInfoContract.IUserInfoActivity mIUserInfoActivity) {
        this.mIUserInfoActivity = mIUserInfoActivity;
        // 设置逻辑
        mIUserInfoActivity.setPresenter(this);
        // 设置生命周期
        mIUserInfoActivity.setILifeCycle(this);
    }

    @Override
    public void loadUserInfo() {
        String userId = mIUserInfoActivity.loadUserId();
        System.out.println("ddddddddddddddddddddddddddd userId = " + userId);
        mIUserInfoActivity.showLoading();//接口请求前显示loading
        //这里模拟接口请求回调-
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                //模拟接口返回的json,并转换为javaBean
                UserInfoModel userInfoModel = new UserInfoModel("小宝", 1, "杭州");
                mIUserInfoActivity.showUserInfo(userInfoModel);
                mIUserInfoActivity.dismissLoading();
            }
        }, 3000);
    }

    @Override
    public void start() {
        loadUserInfo();
    }

    @Override
    public void onRestart() {
        System.out.println("ddddddddddddddddddddd present onRestart");
    }

    @Override
    public void onCreate() {
        System.out.println("ddddddddddddddddddddd present onCreate");
    }

    @Override
    public void onStart() {
        System.out.println("ddddddddddddddddddddd present onStart");
    }

    @Override
    public void onResume() {
        System.out.println("ddddddddddddddddddddd present onResume");
    }

    @Override
    public void onPause() {
        System.out.println("ddddddddddddddddddddd present onPause");
    }

    @Override
    public void onStop() {
        System.out.println("ddddddddddddddddddddd present onStop");
    }

    @Override
    public void onDestroy() {
        System.out.println("ddddddddddddddddddddd present onDestroy");
    }
}

上面代码主要是将activity 界面层与逻辑层关联起来、实现生命周期映射接口、实现逻辑层接口,有不懂得童鞋可以结合view层多看看就明白了,fragment逻辑层类似activity,就不多做分析了。

童鞋们,笔者写的这个mvp是不是很简单?大家可以尝试去写下。

项目地址: MvpDemo

效果图如下:

作者:码无止境
链接:https://www.jianshu.com/p/11235e7bcd8e

转载请注明:Android开发中文站 » Android mvp分层架构优雅写代码

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