Google官方架构MVP解析与实战
wbqdavid
9年前
<h3>1 前言</h3> <p>当然对于MVP的解说也是使用也是层出不穷，我也网络上也能看到各种版本的解说，之前博客也有文章的更新，里面有MVP的详细说明和项目代码---><a href="http://www.open-open.com/lib/view/open1462626318543.html">Android中的MVP模式，带实例</a>。</p> <p>本篇文章将参考 google官方android MVP架构项目的实现，来实现自己的项目。或许看了这篇文章之后，你再去梳理一下google官方架构项目，会让你收获更多。官方的实例肯定具有更好的<strong>权威性</strong>。</p> <p><strong>推荐关注安卓各种架构相关文章合集github地址：<a href="/misc/goto?guid=4959672635985726459">AndroidArchitectureCollection</a></strong></p> <h3>2 google官方MVP架构解析</h3> <p>1 项目目录</p> <p>打开github，展开项目目录，会发现项目结构的组织方式是按照功能进行分模块的，当然根据个人情况，也可以按照ui，model，view，presenter这种情况进行划分组织目录。</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/67a998178e8774ad43f9a6d4cc601d1a.png"></p> <p>google官方MVP架构目录视图</p> <p><br> <strong>2 具体实现流程</strong></p> <p>我们将关注度放到具体的一个taskdetail模块当中来解析实现MVP的流程。</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/b36e24b4b90ed5e8d4eb54dbcab9ebd5.png"></p> <p>taskdetail模块</p> <p><br> <strong>2.1 TaskDetailContract</strong><br> 可以看到这里是通过一个协议类XXXContract来对View和Presenter的接口进行继承。这样做的好处也就是，我们可以将基础的View层的操作放在BaseView里面,对基础的Presenter层的操作放在BasePresenter里面。减少后续代码的重复。一个协议类也将View和Presenter管理起来，方便操作。</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/502d82495487ea8cbc26bb62daed8cc4.png"></p> <p><br> <strong>2.2 BaseView</strong><br> 那么来看看BaseView,主要是有一个setPresenter的操作，MVP中Presenter和View层是需要交互的，这里通过setPresenter操作，我们也就可以获得Presenter层的实例进行交互了。所以在我们自己的代码中，我们也可以将加载的loading，以及加载错误页面，加载失败页面等操作放在BaseView里面，这是每个View都会有的：</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/ed82069554720b1334bf4344d2c771b0.png"></p> <p><strong>2.3 BasePresenter</strong><br> BasePresenter中只有一个start方法，表示“开始”，我们可以在这里进行数据加载初始化等。</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/44c7f36bef36eb2fe5485f0b59d6c97e.png"></p> <p><br> <strong>2.3 TaskDetailActivity</strong><br> 可以看到这里这里一个初始化了fragment的activity，主要操作当让是new了一个XXXPresenter。activity在项目中是一个全局的控制者，负责创建view以及presenter实例，并将二者联系起来，</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/39216c15c0366df6112ce06c26e5b884.png"></p> <p><strong>2.4 TaskDetailFragment</strong><br> Fragment是MVP中View的实现类，它不与Model 层进行交互，只和presenter的实例进行交互。</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/719eb5fb49866160032312dfe1e8964f.png"></p> <p><br> <strong>2.5 TaskDetailPresenter</strong><br> Presenter的真正实现类，在这里进行model层和view层的交互。</p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/8d1262b34ab7b70fdf85e0ba8fe159b0.png"></p> <blockquote> <p>通过上面的分析，在来梳理一下整个步骤：<br> <strong>1 </strong>官方MVP实例，通过协议类XXXContract来对View和Presenter的接口进行内部继承。是对BaseView和BasePresenter的进一步封装，所以我们实现的View和Presenter也只需要继承XXXContract中的对应内部接口就行。</p> </blockquote> <p><strong>2 </strong>activity的作用主要是创建View（这里是相应的fragment），以及创建presenter，并把view传递给presenter</p> <p><strong>3 </strong>在presenter的实现类的构造函数中，通过view的setPresenter，让view获得了presenter实例。这样view中就可以对Presenter中的方法进行操作了。</p> <p><strong>4 </strong>在presenter的实现类中，可以对Model数据进行操作。实例中，数据的获取、存储、数据状态变化都是model层的任务，presenter会根据需要调用该层的数据处理逻辑并在需要时将回调传入。这样model、presenter、view都只处理各自的任务，此种实现确实是单一职责最好的诠释。</p> <h3>3 实战应用：</h3> <p>说了这么多，通过一个主页面的搭建，来完整的使用MVP吧。<br> <strong>3.1 BaseView</strong><br> 我在这里没有添加setPresenter方法，而是将loading，以及加载错误，网络加载错误等页面都放在了这里面。</p> <pre> <code class="language-java">public interface BaseView { // void setPresenter(P presenter); void showLoading(String msg); void hideLoading(); void showError(String msg, View.OnClickListener onClickListener); void showEmpty(String msg, View.OnClickListener onClickListener); void showEmpty(String msg, View.OnClickListener onClickListener, int imageId); void showNetError(View.OnClickListener onClickListener); }</code></pre> <p><strong>3.2 BasePresenter</strong><br> 只有一个start方法。将在view界面初始化后调用（onResume方法中）</p> <pre> <code class="language-java">public interface BasePresenter { void start(); }</code></pre> <p><strong>3.3 DrawerMainContract </strong><br> 可以看到相比官方的实例我在其中添加了一个onGetDrawerListListener，主要是用于获取model层数据之后，进行数据的监听。</p> <pre> <code class="language-java">public interface DrawerMainContract { interface Presenter extends BasePresenter{ //获取数据 void getDrawerList(); //头像点击 void onDrawerIconClicked(); //获取fragment void getSelectFragment(int position); } interface View extends BaseView{ //获取数据后，更新界面 void onDrawerListGet(ArrayList<DrawerItemsData.DrawerItem> list); //设置头像 void setDrawerIcon(int resId); //fragment返回后 void onSelectFragmentGet(Fragment fragment); } //数据监听 interface onGetDrawerListListener { void onSuccess(); void onError(); } }</code></pre> <p><strong>3.4 DrawerMainActivity </strong><br> 在开发中Fragment，Activity以及自定义view都可以作为MVP中View的实现。这里也在创建presenter实例的时候传入了当前view。并调用了 mPresenter.getDrawerList()进行获取数据，mPresenter.getSelectFragment(0);设置当前为第一个fragment。</p> <pre> <code class="language-java">/** * Created by Anthony on 2016/5/3. * Class Note: * 1 use{@link DrawerLayout} to * acts as a top-level container for window content that allows for * interactive "drawer" views to be pulled out from the edge of the window. * 2 View in MVP * see {@link DrawerMainContract}------Manager role of MVP * {@link DrawerMainPresenter}---------Presenter * &{@link DrawerMainActivity}---------View * &{@link DrawerItemsData}------------Model */ public class DrawerMainActivity extends AbsBaseActivity implements DrawerMainContract.View, View.OnClickListener { private Toolbar actionBarToolbar; public static DrawerLayout drawerLayout; private ListView mDrawerMenu; private CircleImageView mUserImg; private NavDrawerListAdapter mAdapter; private DrawerMainPresenter mPresenter; @Override protected int getContentViewID() { return R.layout.activity_drawer; } @Override protected void onResume() { super.onResume(); mPresenter.start(); } @Override protected void initViewsAndEvents() { super.initViewsAndEvents();//一定要调用super，进行父类中的一些初始化操作 initDrawerLayout(); setupToolBar(); //hide toolBar ActionBar actionBar = getSupportActionBar(); if (actionBar != null) { actionBar.hide(); } mUserImg = (CircleImageView) findViewById(R.id.user_img); mUserImg.setOnClickListener(this); mDrawerMenu = (ListView) findViewById(R.id.left_menu); // mPresenter = new DrawerMainPresenter(this, mContext); //create and initialize presenter, mPresenter= new DrawerMainPresenter(this,mContext); //use presenter to load data mPresenter.getDrawerList(); //default select first fragment mPresenter.getSelectFragment(0); } protected void initDrawerLayout() { drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); if (drawerLayout == null) { // current activity does not have a drawer. return; } if (getDrawerLayoutId() != 0) { FrameLayout leftLayout = (FrameLayout) findViewById(R.id.left_drawer_layout); View nav_drawer_layout = getLayoutInflater().inflate(getDrawerLayoutId(), null); leftLayout.addView(nav_drawer_layout); } } protected void setupToolBar() { if (actionBarToolbar == null) { actionBarToolbar = (Toolbar) findViewById(R.id.toolbar); if (actionBarToolbar != null) { setSupportActionBar(actionBarToolbar); } } final ActionBar ab = getSupportActionBar(); if (ab == null) return; ab.setHomeAsUpIndicator(R.drawable.ic_menu); ab.setDisplayHomeAsUpEnabled(true); } public static void openDrawer() { if (drawerLayout == null) return; drawerLayout.openDrawer(GravityCompat.START); } public static void closeDrawer() { if (drawerLayout == null) return; drawerLayout.closeDrawer(GravityCompat.START); } /** * close drawer if drawer is opening */ @Override public void onBackPressed() { if (drawerLayout.isDrawerOpen(GravityCompat.START)) { closeDrawer(); } else { super.onBackPressed(); } } protected int getDrawerLayoutId() { return R.layout.nav_drawer_layout; } @Override public void onClick(View v) { if (v.getId() == R.id.user_img) { mPresenter.onDrawerIconClicked(); } } @Override public void onDrawerListGet(final ArrayList<DrawerItemsData.DrawerItem> mDrawerItems) { mAdapter = new NavDrawerListAdapter(this, mDrawerItems); mDrawerMenu.setAdapter(mAdapter); mDrawerMenu.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) { if (!BaseUtil.isEmpty(mDrawerItems, i)) { DrawerItemsData.DrawerItem drawerItem = mDrawerItems.get(i); if (drawerItem != null) { mPresenter.getSelectFragment(i); } } } }); } @Override public void setDrawerIcon(int resId) { mUserImg.setImageResource(resId); } @Override public void onSelectFragmentGet(Fragment fragment) { closeDrawer(); FragmentManager fragmentManager = getSupportFragmentManager(); fragmentManager.beginTransaction() .replace(R.id.content, fragment).commit(); } @Override protected void onNetworkConnected(NetUtils.NetType type) { ToastUtils.getInstance().showToast("this type is"+type); } @Override protected void onNetworkDisConnected() { ToastUtils.getInstance().showToast("no network disconnected"); } @Override protected View getLoadingTargetView() { return null; } // @Override // public void setPresenter(DrawerMainContract.Presenter presenter) { // mPresenter= (DrawerMainPresenter) presenter; // } @Override public void showLoading(String msg) { toggleShowLoading(true, msg); } @Override public void hideLoading() { toggleShowLoading(false, ""); } @Override public void showError(String msg, View.OnClickListener onClickListener) { } @Override public void showEmpty(String msg, View.OnClickListener onClickListener) { toggleShowEmpty(true, msg, onClickListener); } @Override public void showEmpty(String msg, View.OnClickListener onClickListener, int imageId) { toggleShowEmpty(true, msg, onClickListener, imageId); } @Override public void showNetError(View.OnClickListener onClickListener) { ToastUtils.getInstance().showToast("oops ,no network now!"); } }</code></pre> <blockquote> <p>这里也实现了DrawerMainContract.View以及BaseView中的所有方法。</p> </blockquote> <p><strong>3.5 DrawerMainPresenter</strong><br> 对DrawerMainContract.Presenter和DrawerMainContract.<br> onGetDrawerListListener的实现。<br> 可以看到DrawerItemsData就是model层的对象。主要封装的是本地的字符串和图片数据。</p> <pre> <code class="language-java">/** * Created by Anthony on 2016/5/3. * Class Note: Presenter in MVP * see {@link DrawerMainContract}--------Manager role of MVP * &{@link DrawerMainPresenter}------Presenter * &{@link DrawerMainActivity}-------------View * &{@link DrawerItemsData}-----------Model */ public class DrawerMainPresenter implements DrawerMainContract.Presenter, DrawerMainContract.onGetDrawerListListener { private DrawerMainContract.View mView; private Context mContext; private DrawerItemsData mData; public DrawerMainPresenter(DrawerMainContract.View mView, Context mContext) { this.mContext = mContext; this.mView = mView; // mView.setPresenter(this);//bind presenter for View mData = new DrawerItemsData(mContext, this);//bind data listener for Model } @Override public void onDrawerIconClicked() { //已经登录，跳到个人详情页 ToastUtils.getInstance().showToast("icon clicked"); //没有登录 ，则跳到登录页面。。。 } @Override public void getDrawerList() { mData.initItemsData(); } @Override public void getSelectFragment(int position) { if (position == 3) mView.onSelectFragmentGet(new NewsChannelFragment()); else mView.onSelectFragmentGet(new TestFragment()); } @Override public void onSuccess() { mView.onDrawerListGet(mData.mDrawerItems); mView.setDrawerIcon(R.drawable.icon_head); } @Override public void onError() { // show error view mView.showNetError(new View.OnClickListener() { @Override public void onClick(View v) { } }); } @Override public void start() { } }</code></pre> <p><strong>3.6 DrawerItemsData</strong><br> 这就是我主页面的model层的数据，当然后面可能会对这些数据进行修改，或者添加上网络访问。但是你会发现再也不用像以前那样要去修改整个activity了，只需要的是修改这个类。这也是MVP的作用，单一职责。</p> <pre> <code class="language-java">/** * Created by Anthony on 2016/5/3. * Class Note: * drawer list item data. * */ public class DrawerItemsData { private Context mContext; public ArrayList<DrawerItem> mDrawerItems; private String[] mMenuTitles; private TypedArray mMenuIconsTypeArray; private TypedArray mMenuIconTintTypeArray; private DrawerMainContract.onGetDrawerListListener mListener; public DrawerItemsData(Context context, DrawerMainContract.onGetDrawerListListener listener) { this.mContext = context; this.mListener =listener; mDrawerItems=new ArrayList<>(); } public void initItemsData() { mMenuTitles = mContext.getResources().getStringArray(R.array.nav_drawer_items); // nav drawer icons from resources mMenuIconsTypeArray = mContext.getResources() .obtainTypedArray(R.array.nav_drawer_icons); mMenuIconTintTypeArray = mContext.getResources() .obtainTypedArray(R.array.nav_drawer_tint); for (int i = 0; i < mMenuTitles.length; i++) { mDrawerItems.add(new DrawerItem(mMenuTitles[i], mMenuIconsTypeArray .getResourceId(i, -1), mMenuIconTintTypeArray.getResourceId(i, -1))); } mMenuIconsTypeArray.recycle(); if(mDrawerItems.size()==mMenuTitles.length){ mListener.onSuccess(); }else{ mListener.onError(); } } public class DrawerItem { private String title; private int icon; //图片颜色 private int tint; private String count = "0"; // boolean to set visiblity of the counter private boolean isCounterVisible = false; public DrawerItem(){} public DrawerItem(String title, int icon, int tint){ this.title = title; this.icon = icon; this.tint = tint; } public DrawerItem(String title, int icon, boolean isCounterVisible, String count){ this.title = title; this.icon = icon; this.isCounterVisible = isCounterVisible; this.count = count; } public String getTitle(){ return this.title; } public int getIcon(){ return this.icon; } public String getCount(){ return this.count; } public boolean getCounterVisibility(){ return this.isCounterVisible; } public void setTitle(String title){ this.title = title; } public void setIcon(int icon){ this.icon = icon; } public void setCount(String count){ this.count = count; } public int getTint() { return tint; } public void setTint(int tint) { this.tint = tint; } public void setCounterVisibility(boolean isCounterVisible){ this.isCounterVisible = isCounterVisible; } } }</code></pre> <p>具体请参看<strong>本篇文章项目github地址：<a href="/misc/goto?guid=4959672636079178786">MVPCommon</a></strong></p> <p><img alt="google官方架构MVP解析与实战" src="https://simg.open-open.com/show/513fd8bf4713b1f597387108a2653552.gif"></p> <p>项目效果</p> <h3>4 参考资料：</h3> <p><a href="http://www.open-open.com/lib/view/open1460535364435.html">Android官方MVP架构示例项目解析</a><br> <strong><a href="/misc/goto?guid=4959672635985726459">AndroidArchitectureCollection</a></strong></p> <p> </p> <p><strong>本篇文章项目github地址：<a href="/misc/goto?guid=4959672636079178786">MVPCommon</a></strong></p> <p>文／<a href="/misc/goto?guid=4959672636187032718">CameloeAnthony</a>（简书）<br> </p>