DataBinding 绑定Recyclerview及点击事件

最近在学习DataBinding，在这里记录下学习的轨迹
收获：
1代码解耦。
2少些很多没有营养的代码，美观度高！
遇坑：
1官方文档 https://developer.android.com/topic/libraries/data-binding/index.html#listener_bindings 写的真是简单，
只提供码片段，需要结合博客和别的资料一齐看，才大概明白其中的奥妙。
2不容易定位错误。编译通过，无法安装。请看上篇文章 https://blog.csdn.net/qq_35599978/article/details/80028278 
3如果绑定数据的XML需要增加 那么数据绑定的XXBinding无法调用.setVariable(),因为项目没有编译。后来发现就算
我手动build ，clean，sync project，或者删掉.build文件,再sync project，还是不管用，只能关掉studio，再打开，你发现
世界真美好。我的studio version 3.1

Activity主页布局代码

RecyclerView Item 布局代码

点击事件的接口

public interface ItemClick {
    void onClicked(View veiw, User user);
}

Activitie 代码

public class ScrollingActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityScrolling2Binding binding = DataBindingUtil.setContentView(this, R.layout.activity_scrolling2);
        UserBean bean = new UserBean("andry","13years","swimming");
        binding.setUserbean(bean);
        bean.setName("new_name");
        binding.recycleVeiw.setAdapter(new UserAdapter(new ItemClick() {
            @Override
            public void onClicked(View veiw, User user) {
                                Snackbar.make(veiw, user.getName(), Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        }));
        binding.recycleVeiw.setLayoutManager(new LinearLayoutManager(this,
                LinearLayoutManager.VERTICAL,false));
    }
}

adapter 对应的bean 

public class User extends BaseObservable {

    public User(String name, @DrawableRes int res) {
        this.name = name;
        this.res = res;
    }

    String name;
   public  @Bindable int res;

    @Bindable
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
        notifyPropertyChanged(BR.name);
    }

    public void setRes(int res) {
        this.res = res;
    }

    public User getData() {
        return this;
    }
}

adapter对应的代码

public class UserAdapter extends RecyclerView.Adapter {
    ItemClick itemClick;
    @NonNull
    private List mUsers;
    private static final int USER_COUNT = 10;
    public UserAdapter(ItemClick itemClick) {
        this.itemClick = itemClick;
        mUsers = new ArrayList<>(10);
        for (int i = 0; i < USER_COUNT; i ++) {
            User user = new User("name -- "+i, R.drawable.ic_launcher_background);
            mUsers.add(user);
        }
    }

    @Override
    public UserHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        ItemRecycleviewBinding binding = DataBindingUtil.
                inflate(LayoutInflater.from(parent.getContext())
                        ,R.layout.item_recycleview,
                        parent,
                        false);
        UserHolder userHolder = new UserHolder(binding.getRoot());
        userHolder.setBinding(binding);
        return userHolder;
    }

    @Override
    public void onBindViewHolder(UserHolder holder, int position) {
        holder.bind(mUsers.get(position),itemClick);

    }

    @Override
    public int getItemCount() {
        return mUsers.size();
    }



    public static class UserHolder extends RecyclerView.ViewHolder {
        private ItemRecycleviewBinding mBinding;

        public UserHolder(View itemView) {
            super(itemView);

        }

        public void bind(@NonNull User user,ItemClick itemClick) {
            mBinding.setUser(user);
            mBinding.executePendingBindings();
            mBinding.setItemclidk(itemClick);
        }

        public void setBinding(ItemRecycleviewBinding binding) {
            this.mBinding = binding;
        }
    }
}

activity对应的viewmodel

public  class UserBean  {
    public String name,age,hobby;


    public String getName() {
        return name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getHobby() {
        return hobby;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }

    public UserBean(String name, String age, String hobby) {
        this.name = name;
        this.age = age;
        this.hobby = hobby;
    }

    public void setName(String name) {
        this.name = name;
//        notifyPropertyChanged(BR.userbean);
    }
}