Android MVVM 框架搭建

MVVM 概述

谈谈对MVVM的看法

说到MVVM，不得不提MVC、MVP，前面的那对CP，在某些角度或理解上，倒挺符合他们CP的气质，毕竟他们真的太相似了，写完这三篇文章之后，会专门说说开发的时候该如何去选用这些框架。

言归正传，MVVM新引入了VM的概念，也就是ViewModel，用的时候可以继承ViewModel或者AndroidViewModel，谈到这里，不禁要想，这才是google的亲儿子吗，试问，用MVC的时候Android提供了Controller吗？MVP时android提供了Presenter吗？写到这里的时候，小编马上就去搜索了下，还真有Presenter，我是瑟瑟发抖，真准备求android 粑粑原谅，看了看源码，不禁把肾放回了腰间。androidx.leanback.widget.Presenter 源码有点长就不贴了，先看看示例

  public class StringTextViewPresenter extends Presenter {
    // This class does not need a custom ViewHolder, since it does not use
    // a complex layout.

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup parent) {
        return new ViewHolder(new TextView(parent.getContext()));
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, Object item) {
        String str = (String) item;
        TextView textView = (TextView) viewHolder.mView;
        textView.setText(item);
    }

    @Override
    public void onUnbindViewHolder(ViewHolder viewHolder) {
        // Nothing to unbind for TextView, but if this viewHolder had
        // allocated bitmaps, they can be released here.
    }
}

从例子上看，类似于在Adapter中的做法，虽然如此也能实现MVP的效果，并且这种做法会使View变得更干净，但是这个时候除了xml，还有V的存在吗？貌似这是最理想的状态，氮素啊，这不又回到了Activity的状态了。所以，我姑且就觉得这不是为MVP准备的。
更何况还有DataBinding，MVVM简直如有神助。

Model–View–ViewModel (MVVM) 是一个软件架构设计模式

MVC：（View-Model-Controller）
将View、Model、Controller代码块进行划分，使得程序大部分分离，降低耦合。这个模块，后续会出一个专门的文章，之所以放在最后，文章中会提到。
【MVP：（VIew-Model-Presenter）

Image text

Presenter整个功能的服务者，当用户通过界面（View）与应用进行交互或潜在交互时，界面将有效事件上报给Presenter，Presenter则根据事件需求进行处理，包括与数据（Model）之间的交互。形象来说就是：MVP就是一个非自助式餐厅，顾客就相当于我们的用户，餐厅本身相当于View，餐厅工作人员相当于Presenter，餐厅的食材相当于Model。用户与View进行交互时，相当于客户来到餐厅，此时会触发工作人员进行服务，有点餐操作时，Presenter获取Model数据，并呈现给用户。

MVVM：（Model–View–ViewModel）

Image text

MVVM可以算是MVP的升级版，将Presenter改名为ViewModel。关键在于View和Model的双向绑定，当View有用户输入后，ViewModel通知Model更新数据，同理Model数据更新后，ViewModel通知View更新。

MVVM 使用到的库

1、Android官方架构组件Lifecycle
2、Android官方架构组件ViewModel
3、Android官方架构组件LiveData
4、Android官方架构组件Paging
5、Android官方架构组件Navigation
6、Android官方架构组件Data
7、Android-common
8、Android-common-mvvm

MVVM 实现

定义基类

1、BaseVActivity

package com.ww7h.common.mvvm.v;

import android.databinding.DataBindingUtil;
import android.databinding.ViewDataBinding;

import com.ww7h.ww.common.bases.activity.BaseActivity;

/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   Android-common-mvvm
 * 包名：     com.ww7h.common.mvvm.v
 * 创建时间：  2019/4/5 18:54
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public abstract class BaseVActivity<T extends BaseActivity<T>, B extends ViewDataBinding> extends BaseActivity<T> {

    protected B vdBinding;

    @Override
    protected boolean getDesignPattern() {
        return true;
    }

    @Override
    protected void initContentView() {
        super.initContentView();
        vdBinding = DataBindingUtil.setContentView(this, getContentView());
    }
}

2、BaseVFragment

package com.ww7h.common.mvvm.v;

import android.databinding.DataBindingUtil;
import android.databinding.ViewDataBinding;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.ww7h.ww.common.bases.fragment.BaseFragment;

import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;


/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   Android-common-mvvm
 * 包名：     com.ww7h.common.mvvm.v
 * 创建时间：  2019/4/5 18:57
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public abstract class BaseVFragment<T extends BaseFragment<T>, B extends ViewDataBinding> extends BaseFragment<T> {

    /**
     * 当前视图绑定的对象
     */
    protected B vdBinding;

    @Nullable
    @Override
    protected View getContentView(@NotNull LayoutInflater inflater, @Nullable ViewGroup container) {
        vdBinding = DataBindingUtil.inflate(inflater, getResourceId() ,container , false);
        return vdBinding.getRoot();
    }

    @Override
    protected boolean getDesignPattern() {
        return true;
    }
}

调用Demo

1、定义layout文件，主要差别，root标签<layout></layout>，数据绑定使用<data></data>标签，<variable></variabl>标签用来绑定数据，@{}数据使用

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>
        <variable
            name="mainDetailModel"
            type="com.ww7h.purchasing.main.model.MainDetailModel"/>

        <variable
            name="event"
            type="com.ww7h.purchasing.main.event.MainDetailEvent"/>

    </data>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/jump_next_btn"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:onClick="@{event.jumpClick}"/>


        <RadioGroup
            android:id="@+id/b_nav_group"
            android:layout_alignParentBottom="true"
            android:gravity="center_vertical"
            android:layout_width="match_parent"
            android:layout_height="@dimen/dp_54"
            android:orientation="horizontal">
            <com.ww7h.ww.common.bases.view.radiobutton.RemindRadioButton
                android:id="@+id/b_nav_1"
                android:checked="true"
                android:textSize="@dimen/sp_12"
                android:text="@{mainDetailModel.navi1Name}"
                app:remindMarginRight="@dimen/dp_30"
                app:remindNumber="@{mainDetailModel.navi1Number}"
                app:remindTextWidth="10dp"
                app:remindTextHeight="10dp"
                app:remindTextSize="8sp"
                app:remindTextColor="@color/color_6f"
                app:remindTextBgColor="@color/color_2f230"
                android:textColor="@color/bottom_nav_text_color"
                android:gravity="center"
                android:drawableTop="@drawable/bottom_nav_check_icon1"
                android:button="@null"
                android:layout_weight="1"
                android:layout_width="@dimen/dp_0"
                android:layout_height="wrap_content" />
            <com.ww7h.ww.common.bases.view.radiobutton.RemindRadioButton
                android:id="@+id/b_nav_2"
                android:textSize="@dimen/sp_12"
                android:text="@{mainDetailModel.navi2Name}"
                app:remindNumber="@{mainDetailModel.navi2Number}"
                app:remindTextWidth="5dp"
                app:remindTextHeight="10dp"
                app:remindTextSize="8sp"
                app:remindTextColor="@color/color_6f"
                app:remindTextBgColor="@color/color_2f230"
                app:remindMarginRight="@dimen/dp_30"
                android:textColor="@color/bottom_nav_text_color"
                android:drawableTop="@drawable/bottom_nav_check_icon2"
                android:gravity="center"
                android:button="@null"
                android:layout_weight="1"
                android:layout_width="@dimen/dp_0"
                android:layout_height="wrap_content" />
            <com.ww7h.ww.common.bases.view.radiobutton.RemindRadioButton
                android:id="@+id/b_nav_3"
                android:textSize="@dimen/sp_12"
                android:text="@{mainDetailModel.navi3Name}"
                app:remindNumber="@{mainDetailModel.navi3Number}"
                app:remindMarginRight="@dimen/dp_30"
                app:remindTextWidth="10dp"
                app:remindTextHeight="10dp"
                app:remindTextSize="8sp"
                app:remindTextColor="@color/color_6f"
                app:remindTextBgColor="@color/color_2f230"
                android:textColor="@color/bottom_nav_text_color"
                android:drawableTop="@drawable/bottom_nav_check_icon3"
                android:gravity="center"
                android:button="@null"
                android:layout_weight="1"
                android:layout_width="@dimen/dp_0"
                android:layout_height="wrap_content" />
            <com.ww7h.ww.common.bases.view.radiobutton.RemindRadioButton
                android:id="@+id/b_nav_4"
                android:textSize="@dimen/sp_12"
                android:text="@{mainDetailModel.navi4Name}"
                app:remindNumber="@{mainDetailModel.navi4Number}"
                app:remindMarginRight="@dimen/dp_30"
                app:remindTextWidth="10dp"
                app:remindTextHeight="10dp"
                app:remindTextSize="8sp"
                app:remindTextColor="@color/color_6f"
                app:remindTextBgColor="@color/color_2f230"
                android:textColor="@color/bottom_nav_text_color"
                android:drawableTop="@drawable/bottom_nav_check_icon4"
                android:gravity="center"
                android:button="@null"
                android:layout_weight="1"
                android:layout_width="@dimen/dp_0"
                android:layout_height="wrap_content" />
        </RadioGroup>
    </RelativeLayout>

</layout>

2、创建Activity，完成视图绑定和调用

package com.ww7h.purchasing.main.view;

import android.arch.lifecycle.LiveData;
import android.arch.lifecycle.Observer;
import android.arch.lifecycle.ViewModelProviders;
import android.content.Intent;
import android.support.annotation.Nullable;

import com.ww7h.common.mvvm.v.BaseVActivity;
import com.ww7h.purchasing.PTApplication;
import com.ww7h.purchasing.R;
import com.ww7h.purchasing.databinding.ActivityMainDetailBinding;
import com.ww7h.purchasing.main.event.MainDetailEvent;
import com.ww7h.purchasing.main.model.MainDetailModel;
import com.ww7h.purchasing.main.viewmodel.MainDetailViewModel;
import com.ww7h.ww.common.utils.DensityUtil;
import com.ww7h.ww.common.utils.LogUtil;
import com.ww7h.ww.common.utils.ScreenUtil;


/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   PurchasingTreasure
 * 包名：     com.ww7h.purchasing.main.view
 * 创建时间：  2019/4/23 20:53
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class MainDetailActivity extends BaseVActivity<MainDetailActivity, ActivityMainDetailBinding> {

    MainDetailViewModel mViewModel;

    @Override
    protected int getContentView() {
        return R.layout.activity_main_detail;
    }

    @Override
    protected void initAction() {
        vdBinding.setEvent(new MainDetailEvent(mViewModel));
    }

    @Override
    protected void initView() {

        MainDetailViewModel.Factory factory = new MainDetailViewModel.Factory(PTApplication.getInstance());
        mViewModel = ViewModelProviders.of(this, factory).get(MainDetailViewModel.class);
        subscribeUi(mViewModel.getMainDetailModel());

    }

    private MainDetailModel mainDetailModel;

    private void subscribeUi(LiveData<MainDetailModel> modelLiveData) {
        modelLiveData.observe(this, new Observer<MainDetailModel>() {
            @Override
            public void onChanged(@Nullable MainDetailModel mainModel) {
                if (mainModel != null) {
                    float width = ScreenUtil.Companion.getScreenWidth(activity) / 8f;
                    mainDetailModel = mainModel;
                    vdBinding.setMainDetailModel(mainDetailModel);

                    vdBinding.bNav1.setRemindWidth(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav1.setRemindHeight(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav1.setRemindMarginRight(width - DensityUtil.INSTANCE.sp2px(activity, 15));

                    vdBinding.bNav2.setRemindWidth(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav2.setRemindHeight(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav2.setRemindMarginRight(width - DensityUtil.INSTANCE.sp2px(activity, 20));

                    vdBinding.bNav3.setRemindWidth(DensityUtil.INSTANCE.sp2px(activity, 15));
                    vdBinding.bNav3.setRemindHeight(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav3.setRemindMarginRight(width - DensityUtil.INSTANCE.sp2px(activity, 25));

                    vdBinding.bNav4.setRemindWidth(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav4.setRemindHeight(DensityUtil.INSTANCE.sp2px(activity, 10));
                    vdBinding.bNav4.setRemindMarginRight(width - DensityUtil.INSTANCE.sp2px(activity, 15));
                }
                vdBinding.executePendingBindings();
            }
        });
    }



    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        LogUtil.e(TAG, "-------");

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        LogUtil.e(TAG, "-------");

    }


}

3、创建Model，需要继承BaseObservable，get方法添加@Bindable注解，set方法添加notifyPropertyChanged(BR.navi1Number)，完成数据双向绑定。

package com.ww7h.purchasing.main.model;

import android.databinding.BaseObservable;
import android.databinding.Bindable;

import com.ww7h.common.mvvm.BR;


/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   PurchasingTreasure
 * 包名：     com.ww7h.purchasing.main.model
 * 创建时间：  2019/4/25 20:55
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class MainDetailModel extends BaseObservable {

    private String navi1Name;
    private String navi2Name;
    private String navi3Name;
    private String navi4Name;

    private int navi1Number;
    private int navi2Number;
    private int navi3Number;
    private int navi4Number;

    @Bindable
    public String getNavi1Name() {
        return navi1Name;
    }

    @Bindable
    public int getNavi1Number() {
        return navi1Number;
    }

    @Bindable
    public String getNavi2Name() {
        return navi2Name;
    }

    @Bindable
    public int getNavi2Number() {
        return navi2Number;
    }

    @Bindable
    public String getNavi3Name() {
        return navi3Name;
    }

    @Bindable
    public int getNavi3Number() {
        return navi3Number;
    }

    @Bindable
    public String getNavi4Name() {
        return navi4Name;
    }

    @Bindable
    public int getNavi4Number() {
        return navi4Number;
    }

    public void setNavi1Name(String navi1Name) {
        this.navi1Name = navi1Name;
    }

    public void setNavi2Name(String navi2Name) {
        this.navi2Name = navi2Name;
    }

    public void setNavi3Name(String navi3Name) {
        this.navi3Name = navi3Name;
    }

    public void setNavi4Name(String navi4Name) {
        this.navi4Name = navi4Name;
    }

    public void setNavi1Number(int navi1Number) {
        this.navi1Number = navi1Number;
        notifyPropertyChanged(BR.navi1Number);
    }

    public void setNavi2Number(int navi2Number) {
        this.navi2Number = navi2Number;
    }

    public void setNavi3Number(int navi3Number) {
        this.navi3Number = navi3Number;
    }

    public void setNavi4Number(int navi4Number) {
        this.navi4Number = navi4Number;
    }
}

4、创建ViewModel，创建、操作数据

package com.ww7h.purchasing.main.viewmodel;

import android.app.Application;
import android.arch.lifecycle.LiveData;
import android.arch.lifecycle.MutableLiveData;
import android.arch.lifecycle.ViewModel;
import android.arch.lifecycle.ViewModelProvider;
import android.support.annotation.NonNull;

import com.ww7h.common.mvvm.vm.BaseVM;
import com.ww7h.purchasing.main.model.MainDetailModel;

import org.jetbrains.annotations.NotNull;

/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   PurchasingTreasure
 * 包名：     com.ww7h.purchasing.main.viewmodel
 * 创建时间：  2019/4/26 10:25
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class MainDetailViewModel extends BaseVM {

    private MainDetailModel mainDetailModel;

    private MainDetailViewModel(@NonNull Application application) {
        super(application);
    }

    public LiveData<MainDetailModel> getMainDetailModel() {
        mainDetailModel = new MainDetailModel() {
            {
                setNavi1Name("清单");
                setNavi1Number(2);
                setNavi1Name("日程");
                setNavi2Number(88);
                setNavi1Name("购买人");
                setNavi3Number(111);
                setNavi1Name("邮寄");
                setNavi4Number(1);
            }
        };

        return new MutableLiveData<MainDetailModel>() {
            {
                postValue(mainDetailModel);
            }
        };
    }

    public void updateNavi1Number(int number) {
        mainDetailModel.setNavi1Number(number);
    }

    public static class Factory extends ViewModelProvider.NewInstanceFactory {

        @NonNull
        private final Application mApplication;

        public Factory(@NonNull Application application) {
            mApplication = application;
        }

        @NotNull
        @Override
        public <T extends ViewModel> T create(@NotNull Class<T> modelClass) {
            return (T) new MainDetailViewModel(mApplication);
        }
    }

}

5、创建事件管理类，用来监听事件，并输出给ViewModel

package com.ww7h.purchasing.main.event;

import android.view.View;

import com.ww7h.purchasing.main.viewmodel.MainDetailViewModel;
import com.ww7h.ww.common.utils.ToastUtil;

/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   PurchasingTreasure
 * 包名：     com.ww7h.purchasing.main.view
 * 创建时间：  2019/4/26 11:40
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class MainDetailEvent {

    private MainDetailViewModel viewModel;

    public MainDetailEvent(MainDetailViewModel viewModel) {
        this.viewModel = viewModel;
    }

    public void jumpClick(View view) {

        ToastUtil.showShortToast("123");

        viewModel.updateNavi1Number(1);
    }

}

6、BaseVFragment的使用

package com.ww7h.purchasing.main.view;

import android.arch.lifecycle.LiveData;
import android.arch.lifecycle.Observer;
import android.arch.lifecycle.ViewModelProviders;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;

import com.ww7h.common.mvvm.v.BaseVFragment;
import com.ww7h.purchasing.PTApplication;
import com.ww7h.purchasing.R;
import com.ww7h.purchasing.databinding.FragmentMainBinding;
import com.ww7h.purchasing.main.model.MainModelInterface;
import com.ww7h.purchasing.main.view.adapter.MainAdapter;
import com.ww7h.purchasing.main.viewmodel.MainViewModel;
import com.ww7h.ww.common.bases.view.recyclerview.decoration.SpaceItemDecoration;
import com.ww7h.ww.common.listeners.OnRecyclerItemClick;
import com.ww7h.ww.common.utils.DensityUtil;

import java.util.List;
import java.util.Objects;

/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   PurchasingTreasure
 * 包名：     com.ww7h.purchasing
 * 创建时间：  2019/4/17 14:51
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class MainFragment extends BaseVFragment<MainFragment, FragmentMainBinding> implements OnRecyclerItemClick<MainModelInterface> {

    private MainAdapter mainAdapter;

    @Override
    public int getResourceId() {
        return R.layout.fragment_main;
    }

    @Override
    public void initAction() {

    }

    @Override
    public void initView() {
        mainAdapter = new MainAdapter(getActivity());
        mainAdapter.setRecyclerItemClick(this);
        vdBinding.mainContentRv.setLayoutManager(new LinearLayoutManager(getActivity()));
        vdBinding.setMainAdapter(mainAdapter);
        vdBinding.mainContentRv.addItemDecoration(new SpaceItemDecoration(DensityUtil.INSTANCE.dp2px(Objects.requireNonNull(getActivity()),1f),1));
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        MainViewModel.Factory factory = new MainViewModel.Factory(PTApplication.getInstance());
        final MainViewModel viewModel = ViewModelProviders.of(this, factory).get(MainViewModel.class);
        subscribeUi(viewModel.getMainModelList());
    }

    private void subscribeUi(LiveData<List<MainModelInterface>> liveData) {
        liveData.observe(this, new Observer<List<MainModelInterface>>() {
            @Override
            public void onChanged(@Nullable List<MainModelInterface> mainModels) {
                if (mainModels != null) {
                    mainAdapter.replaceDataList(mainModels);
                }
                vdBinding.executePendingBindings();
            }
        });
    }

    @Override
    public void onItemClick(@org.jetbrains.annotations.Nullable MainModelInterface mainModelInterface) {
        assert mainModelInterface != null;
        Intent intent = new Intent(getActivity(), MainDetailActivity.class);
        startActivity(intent);
    }

}

7、适配器视图绑定

package com.ww7h.purchasing.main.view.adapter;

import android.content.Context;
import android.databinding.DataBindingUtil;
import android.support.annotation.NonNull;
import android.view.LayoutInflater;
import android.view.ViewGroup;

import com.ww7h.purchasing.R;
import com.ww7h.purchasing.databinding.ItemMainBinding;
import com.ww7h.purchasing.main.model.MainModelInterface;
import com.ww7h.ww.common.bases.view.recyclerview.adapters.BaseRecyclerViewAdapter;
import com.ww7h.ww.common.bases.view.recyclerview.adapters.RecyclerViewHolder;
import com.ww7h.ww.common.listeners.OnRecyclerItemClick;


/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   PurchasingTreasure
 * 包名：     com.ww7h.purchasing.main.view.adapter
 * 创建时间：  2019/4/17 16:51
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class MainAdapter extends BaseRecyclerViewAdapter<MainAdapter.MainViewHolder, MainModelInterface> {

    private OnRecyclerItemClick<MainModelInterface> recyclerItemClick;
    private Context mContext;

    public MainAdapter(Context context) {
        mContext = context;
    }

    @Override
    protected void onBindViewHolder(MainViewHolder holder, int position, int viewType) {
        holder.binding.setOnItemClickListener(recyclerItemClick);
        holder.binding.setItemModel(getItem(position));
    }

    @Override
    protected boolean areItemsTheSame(MainModelInterface oldM, MainModelInterface newM) {
        return oldM.getItemName().equals(newM.getItemName());
    }

    @Override
    protected boolean areContentsTheSame(MainModelInterface oldM, MainModelInterface newM) {
        return oldM.getItemName().equals(newM.getItemName())
                && oldM.getItemContent().equals(newM.getItemContent())
                && oldM.getItemIconPath().equals(newM.getItemIconPath());
    }

    @NonNull
    @Override
    public MainViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        ItemMainBinding binding = DataBindingUtil
                .inflate(LayoutInflater.from(viewGroup.getContext()), R.layout.item_main,
                        viewGroup, false);

        return new MainViewHolder(binding);
    }

    public void setRecyclerItemClick(OnRecyclerItemClick<MainModelInterface> recyclerItemClick) {
        this.recyclerItemClick = recyclerItemClick;
    }

    class MainViewHolder extends RecyclerViewHolder {

        ItemMainBinding binding;

        MainViewHolder(ItemMainBinding binding) {
            super(binding.getRoot());
            this.binding = binding;
        }
    }

}

8、用到的视图

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <variable
            name="mainAdapter"
            type="com.ww7h.purchasing.main.view.adapter.MainAdapter"/>
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/main_content_rv"
            android:adapter="@{mainAdapter}"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>

    </LinearLayout>

</layout>


    <?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>
        <variable
            name="onItemClickListener"
            type="com.ww7h.ww.common.listeners.OnRecyclerItemClick"/>
        <variable
            name="itemModel"
            type="com.ww7h.purchasing.main.model.MainModelInterface"/>
    </data>

    <RelativeLayout
        android:padding="@dimen/dp_10"
        android:background="@color/color_6f"
        android:onClick="@{() -> onItemClickListener.onItemClick(itemModel)}"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:id="@+id/item_icon_iv"
            android:layout_width="@dimen/dp_48"
            android:layout_height="@dimen/dp_48"
            android:scaleType="center"
            app:image="@{itemModel.itemIconPath}"
            android:layout_marginEnd="@dimen/dp_10"
            android:contentDescription="@{itemModel.itemName}" />
        <TextView
            android:id="@+id/item_name_tv"
            android:textSize="@dimen/sp_17"
            android:layout_toEndOf="@+id/item_icon_iv"
            android:text="@{itemModel.itemName}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
        <TextView
            android:layout_toEndOf="@+id/item_icon_iv"
            android:layout_below="@+id/item_name_tv"
            android:text="@{itemModel.itemContent}"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </RelativeLayout>

</layout>

9、图片加载app:image="@{itemModel.itemIconPath}"，定义image

package com.ww7h.common.mvvm.v.adapter;

import android.databinding.BindingAdapter;
import android.widget.ImageView;

import com.bumptech.glide.Glide;

/**
 * ================================================
 * 描述：
 * 来源：     Android Studio.
 * 项目名：   Android-common-mvvm
 * 包名：     com.ww7h.common.mvvm.v.adapter
 * 创建时间：  2019/4/26 16:18
 *
 * @author ww  Github地址：https://github.com/ww7hcom
 * ================================================
 */
public class WidgetBindingAdapter {

    @BindingAdapter({"image"})
    public static void glideLoadImage(ImageView imageView, String url) {
        Glide.with(imageView.getContext()).load(url).into(imageView);
    }

}