mvvm模式的recyclerview通用adapter

最近打算项目重构   打算使用mvvm模式   试着写了一个recyclerview在mvvm模式下的通用adapter  用起来清爽  痛快

 

 

package demo.xinchuang.com.mvvmdemo;

import android.content.Context;
import android.databinding.DataBindingUtil;
import android.databinding.ViewDataBinding;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.List;

/**
 * RecyclerView 通用的 Adapter
 * 

 * Created by suwenlai on 16-12-27.
 */

public class MvvmCommonAdapter extends RecyclerView.Adapter {

    protected Context mContext;
    //所有 item 的数据集合
    protected List mDatas;
    //item 布局文件 id
    protected int mLayoutId;
    protected LayoutInflater mInflater;
    // mvvm绑定的viewModel引用
    private int mVariableId;

    //构造方法
    public MvvmCommonAdapter(List datas, int variableId, Context context, int layoutId) {
        mContext = context;
        mDatas = datas;
        mLayoutId = layoutId;
        mInflater = LayoutInflater.from(mContext);
        mVariableId = variableId;
    }


    public List getmDatas() {
        return mDatas;
    }

    public void setmDatas(List mDatas) {
        this.mDatas = mDatas;
    }

    @Override
    public CommonHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        ViewDataBinding binding = DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()), mLayoutId, parent, false);
        CommonHolder myHolder = new CommonHolder(binding.getRoot());
        myHolder.setBinding(binding);
        return myHolder;
    }

    @Override
    public void onBindViewHolder(CommonHolder holder, int position) {
        holder.binding.setVariable(mVariableId,mDatas.get(position));
        holder.binding.executePendingBindings();
    }


    @Override
    public int getItemCount() {
        return null == mDatas ? 0 : mDatas.size();
    }


    class CommonHolder extends RecyclerView.ViewHolder {
        private ViewDataBinding binding;

        public CommonHolder(View itemView) {
            super(itemView);
        }

        public ViewDataBinding getBinding() {
            return binding;
        }

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

 

 

 

使用方法很简单

 

list.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
list.setAdapter(new MvvmCommonAdapter(mData,BR.myUser,this,R.layout.second_adapter));

刚才有评论问了BR是什么  BR 是编译阶段生成的一个类，功能与 R.java 类似

因为如果myUser的里面的数据有变化了  无法同步更新空间  

所以这里使myUser继承BaseObservable，用 @Bindable 标记过 getter 方法，会在BR生成该字段标识 
然后set方法里添加notifyPropertyChanged(BR.field);

当数据发生变化时还是需要手动发出通知。 通过调用notifyPropertyChanged(BR.field)来通知系统BR.field 的数据已经发生变化，需要更新view

 

public class myUser extends BaseObservable {

    private String nickName;
    private String userface;
    private String userName;
    private String age;

    public User(String nickName, String userface, String userName, String age) {
        this.nickName = nickName;
        this.userface = userface;
        this.userName = userName;
        this.age = age;
    }

    public User() {
    }

    @Bindable
    public String getNickName() {
        return nickName;
    }

    public void setNickName(String nickName) {
        this.nickName = nickName;
        notifyPropertyChanged(BR.nickName);
    }

    @Bindable
    public String getUserface() {
        return userface;
    }

    public void setUserface(String userface) {
        this.userface = userface;
        notifyPropertyChanged(BR.userface);
    }

    @Bindable
    public String getAge() {
        return age;
    }

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

    @Bindable
    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
        notifyPropertyChanged(BR.userName);
    }
}

 

 

 

还有一种方法是 通过ObserableField来实现  

 

public class PlainUser {
    public final ObservableField firstName = new ObservableField<>();
    public final ObservableField nickName= new ObservableField<>();
    public final ObservableInt age = new ObservableInt();
}

具体使用方法可以百度一下

 

xml文件