Android之AAC架构尝试

冷不防 2022-04-10 13:18 484阅读 0赞

一、AAC架构的前世今生

1、关于AAC需先了解一下Android Jetpack，Jetpack 是 Android 软件组件的集合，使您可以更轻松地开发出色的 Android 应用。这些组件可帮助您遵循最佳做法、让您摆脱编写样板代码的工作并简化复杂任务，以便您可以专注于您关心的代码。Jetpack 包含与平台 API 解除捆绑的 [androidx.\*][androidx.] 软件包库。这意味着，它提供向后兼容性并且比 Android 平台更频繁地更新，从而确保您始终可以获取最新且最好的 Jetpack 组件版本。

2、Android Jetpack的优势

（1）组件是为协同工作而构建的，不过也可以单独采用，同时利用 Kotlin 语言功能帮助您提高工作效率；

（2)Android Jetpack 可管理繁琐的 Activity（如后台任务、导航和生命周期管理），以便您可以专注于具体业务；

(3)Android Jetpack 组件围绕现代化设计实践构建而成，具有向后兼容性，可以减少崩溃和内存泄漏。

3、Android Architecture Components(简称AAC)，它是一套新的MVVM架构组件，使App的架构更加健壮,是Android Jetpack的架构组件具有可帮助管理界面组件生命周期、处理数据持久性等的类，以声明方式将可观察数据绑定到界面元素。

相关的API类：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlbmdjaGVuZ3d1MjAxMg_size_16_color_FFFFFF_t_70][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlbmdjaGVuZ3d1MjAxMg_size_16_color_FFFFFF_t_70 1][]

![20190107145924964.png][]

二、代码实战

1、定义model类（省略get 、set方法）

public class NewsDataVo {
        private String id;
        private String newsTitle;
        private String newsContent;
        private String newsUrl;
        private int readNum;
    }

2、定义ViewModel

public class NewsViewModel extends AndroidViewModel {
    
        private MutableLiveData<NewsDataVo> mData;
    
        private LiveData<NewsDataVo> switchDataMap;
    
        LiveData<NewsDataVo> getSwitchDataMap() {
            return switchDataMap;
        }
    
        public NewsViewModel(@NonNull Application application) {
            super(application);
            mData = new MutableLiveData<>();
            switchDataMap = Transformations.switchMap(mData, new Function<NewsDataVo, LiveData<NewsDataVo>>() {
                @Override
                public LiveData<NewsDataVo> apply(NewsDataVo input) {
                    MutableLiveData<NewsDataVo> temp = new MutableLiveData<>();
                    temp.setValue(input);
                    return temp;
                }
            });
    
        }
    
    
        /**
         * 模拟获取网络数据
         */
        void httpGetData() {
            int len = 10;
            for (int i = 0; i < len; i++) {
                NewsDataVo dataVo = new NewsDataVo();
                dataVo.setId("1223" + i);
                dataVo.setNewsTitle("Android AccArchitecture框架简介" + i);
                dataVo.setNewsContent("Android Architecture Components,简称 AAC,一个处理UI的生命周期与数据的持久化的架构" + i);
                dataVo.setReadNum(i);
                mData.setValue(dataVo);
            }
        }
    }

3、定义LifecycleObserver管理View(Activity、Fragment)的生命周期

public class AccLifecycleObserver implements LifecycleObserver {
        private Context context;
        private String tag;
    
        AccLifecycleObserver(Context context) {
            this.context = context;
            tag = context.getClass().getSimpleName();
        }
    
    
        @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
        public void onCreate() {
            Log.i(tag, "onCreate-----" + context.getClass());
        }
    
        @OnLifecycleEvent(Lifecycle.Event.ON_START)
        public void onStart() {
            Log.i(tag, "onStart-----" + context.getClass());
        }
    
        @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
        public void onResume() {
            Log.i(tag, "onResume-----" + context.getClass());
        }
    
        @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
        public void onPause() {
            Log.i(tag, "onPause-----" + context.getClass());
        }
    
        @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
        public void onStop() {
            Log.i(tag, "onStop-----" + context.getClass());
        }
    
        @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
        public void onDestroy() {
            Log.i(tag, "onDestroy-----" + context.getClass());
        }
    }

4、View层交互

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
        private MainActivity mActivity;
        private NewsViewModel newsViewModel;
        private DataAdapter dataAdapter;
        private List<NewsDataVo> mData;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initView();
            addObserver();
        }
    
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.do_btn_tv:
                    newsViewModel.httpGetData();
                    break;
                default:
                    break;
            }
        }
    
        public void initView() {
            mActivity = this;
            mData = new ArrayList<>();
            dataAdapter = new DataAdapter(mData);
            findViewById(R.id.do_btn_tv).setOnClickListener(this);
            RecyclerView recyclerView = findViewById(R.id.data_list_rv);
            recyclerView.setHasFixedSize(true);
            recyclerView.setLayoutManager(new LinearLayoutManager(mActivity));
            recyclerView.setAdapter(dataAdapter);
        }
    
        private void addObserver() {
            AccLifecycleObserver observer = new AccLifecycleObserver(mActivity);
            getLifecycle().addObserver(observer);
            ViewModelProvider.AndroidViewModelFactory instance = ViewModelProvider.AndroidViewModelFactory.getInstance(AccApp.sInstance);
            newsViewModel = instance.create(NewsViewModel.class);
            newsViewModel.getSwitchDataMap().observe(mActivity, new Observer<NewsDataVo>() {
                @Override
                public void onChanged(@Nullable NewsDataVo dataVo) {
                    assert dataVo != null;
                    mData.add(dataVo);
                    dataAdapter.notifyDataSetChanged();
                }
            });
        }
    
    
        class DataAdapter extends RecyclerView.Adapter<DataAdapter.ViewData> {
    
            private List<NewsDataVo> mData;
    
            DataAdapter(List<NewsDataVo> mData) {
                this.mData = mData;
            }
    
            @NonNull
            @Override
            public ViewData onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
                return new ViewData(LayoutInflater.from(mActivity).inflate(R.layout.news_item, viewGroup, false));
            }
    
            @Override
            public void onBindViewHolder(@NonNull ViewData viewData, int i) {
                NewsDataVo newsDataVo = mData.get(i);
                viewData.numTv.setText(newsDataVo.getReadNum() + "人阅读");
                viewData.titleTv.setText(newsDataVo.getNewsTitle());
                viewData.contentTv.setText(newsDataVo.getNewsContent());
            }
    
            @Override
            public int getItemCount() {
                return mData.size();
            }
    
            class ViewData extends RecyclerView.ViewHolder {
                private ImageView imageView;
                private TextView titleTv;
                private TextView contentTv;
                private TextView numTv;
    
                public ViewData(@NonNull View itemView) {
                    super(itemView);
                    imageView = itemView.findViewById(R.id.image_iv);
                    titleTv = itemView.findViewById(R.id.title_tv);
                    contentTv = itemView.findViewById(R.id.content_tv);
                    numTv = itemView.findViewById(R.id.read_num_tv);
                }
            }
        }

布局xml文件

<?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
        <TextView
            android:id="@+id/do_btn_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:layout_marginStart="20dp"
            android:text="渲染数据"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
        
        <android.support.v7.widget.RecyclerView
            android:id="@+id/data_list_rv"
            android:layout_marginTop="5dp"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/do_btn_tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
    </android.support.constraint.ConstraintLayout>
    
    
    
    
    <?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:context=".MainActivity">
    
        <ImageView
            android:id="@+id/image_iv"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:layout_marginStart="10dp"
            android:layout_marginTop="10dp"
            android:scaleType="centerCrop"
            android:src="@drawable/timg"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <android.support.constraint.Barrier
            android:id="@+id/bar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:barrierDirection="right"
            app:constraint_referenced_ids="image_iv"
            app:layout_constraintStart_toEndOf="@id/image_iv" />
    
    
        <TextView
            android:id="@+id/read_num_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:gravity="right"
            android:text="阅读人数5人"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@+id/bar"
            app:layout_constraintTop_toTopOf="parent" />
    
        <TextView
            android:id="@+id/title_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="标题"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@+id/bar"
            app:layout_constraintTop_toBottomOf="@+id/read_num_tv" />
    
    
        <TextView
            android:id="@+id/content_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="内容"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@+id/bar"
            app:layout_constraintTop_toBottomOf="@+id/title_tv" />
    
    </android.support.constraint.ConstraintLayout>

[androidx.]: https://developer.android.google.cn/topic/libraries/support-library/androidx-overview
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[20190107145924964.png]: /images/20220330/a8d7b05651404630a302a20b539b695f.png