recycleView之 databinding简单利用

使用环境：

            简单使用到databinding的时候

使用方法：

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

    <data>
        <import type="android.view.View"/>
        <variable
            name="custom"
            type="com.example.administrator.eitherdemo1.CustomScanActivity"/>

    </data>


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:gravity="center_horizontal"
        android:orientation="vertical">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="@dimen/fifty"
            android:orientation="horizontal"
            >
            <Button
                android:id="@+id/btn"
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:onClick="start"
                android:text="@string/add1" />
            <Button
                android:id="@+id/btn1"
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:onClick="start1"
                android:text="@string/add2" />

        </LinearLayout>


        <android.support.v7.widget.RecyclerView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/recycler"
            android:background="@color/white"
            />


    </LinearLayout>
</layout>

 

 

 

 

mainActivity的代码

 

public class MainActivity extends BaseActivity {

    ActivityMainBinding mainBinding ;
    List<User> users = new ArrayList<User>();
    List<User> us = new ArrayList<>();
    FriendAdapter adapter ;


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mainBinding = DataBindingUtil.setContentView(this,R.layout.activity_main);
        adapter = new FriendAdapter(this,users);
        mainBinding.recycler.setLayoutManager(new LinearLayoutManager(this));
        mainBinding.recycler.setAdapter(adapter);
        adapter.setOnItemClickLitener(new FriendAdapter.OnItemClickLitener() {
            @Override
            public void onItemClick(View view, int position) {
                Toast.makeText(MainActivity.this,"点击当前第"+position+"个条目",Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onItemLongClick(View view, int position) {

            }
        });

    }
    public void start(View view){
//        customScan();
        User user = new User("小明","12","nan");
        adapter.addItem(0,user);
        us.add(user);
    }
    public void start1(View view){
        User user = new User("小红","16","nv");
        adapter.addItem(0,user);
        us.add(user);
    }

    
}

 

 

 

 

3 adpter 中需要注意的

3.1  所有类型的item的父类：

 

public abstract class BaseRecyclerViewHolder<T> extends RecyclerView.ViewHolder {

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

    public abstract void bindData(T data);
}

 

 

 

3.2 adapter：

思路：   创建两个databinding类型的xml文件作为item各种类型的布局；

             创建两个继承了BaseRecyclerViewHolder的类，相关写法已经展示；

             在OnCreateViewHolder()中返回BaseRecyclerViewHolder；

 

public class FriendAdapter extends RecyclerView.Adapter<BaseRecyclerViewHolder> {
    private List<User> strings;
    private Context mcontext;

    public FriendAdapter(Context context, List<User> strings) {
        this.mcontext = context;
        this.strings = strings;

    }


    @Override
    public BaseRecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        switch (viewType){
            case 1:
                ItemRecycleBinding recycleBinding = DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()),R.layout.item_recycle,parent,false);
                return new MyViewHolder(recycleBinding);
            case 2:
                ItemnvBinding itemnvBinding = DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()),R.layout.itemnv,parent,false);
                return new NvViewHolder(itemnvBinding);
        }
            return null;
    }

    @Override
    public void onBindViewHolder(final BaseRecyclerViewHolder holder, int position) {
        holder.bindData(strings.get(position));

        if (mOnItemClickLitener != null)
        {
            holder.itemView.setOnClickListener(new View.OnClickListener()
            {
                @Override
                public void onClick(View v)
                {
                    int pos = holder.getLayoutPosition();
                    mOnItemClickLitener.onItemClick(holder.itemView, pos);
                }
            });

            holder.itemView.setOnLongClickListener(new View.OnLongClickListener()
            {
                @Override
                public boolean onLongClick(View v)
                {
                    int pos = holder.getLayoutPosition();
                    mOnItemClickLitener.onItemLongClick(holder.itemView, pos);
                    return false;
                }
            });
        }
    }

    public interface OnItemClickLitener {
        void onItemClick(View view, int position);

        void onItemLongClick(View view, int position);
    }

    private OnItemClickLitener mOnItemClickLitener;

    public void setOnItemClickLitener(OnItemClickLitener mOnItemClickLitener) {
        this.mOnItemClickLitener = mOnItemClickLitener;
    }

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

    public class MyViewHolder extends BaseRecyclerViewHolder<User> {

        ItemRecycleBinding recycleBinding;

        public MyViewHolder(ViewDataBinding dataBinding) {
            super(dataBinding.getRoot());
            recycleBinding = (ItemRecycleBinding) dataBinding;
        }

        @Override
        public void bindData(User data) {
            recycleBinding.setUser(data);
        }

    }

    public class NvViewHolder extends BaseRecyclerViewHolder<User>{

        ItemnvBinding itemnvBinding;

        public NvViewHolder(ViewDataBinding viewDataBinding) {
            super(viewDataBinding.getRoot());
            itemnvBinding = (ItemnvBinding) viewDataBinding;
        }

        @Override
        public void bindData(User data) {
            itemnvBinding.setUser(data);
        }
    }


    @Override
    public int getItemViewType(int position) {
        String sex = strings.get(position).getSex();
        if ("nan".equals(sex)) {
            return 1;
        } else {
            return 2;
        }
    }
    public void addItem(int position,User s) {
        strings.add(position,s);
        notifyItemInserted(position);
    }
    public void removeItem(int position) {
        strings.remove(position);
        notifyItemRemoved(position);
    }
}

 

 

 

3.3 item的简单布局文件：

 

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

    <data>
        <variable
            name="user"
            type="com.example.administrator.eitherdemo1.bean.User"/>
    </data>


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="@dimen/fifty"
        android:orientation="horizontal">
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="match_parent"
            android:text="@string/sex"
            />
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="match_parent"
            android:id="@+id/textname"
            android:text="@{user.name}"
            />
    </LinearLayout>

</layout>

 

 

 

两个xml文件一样，不一样的知识内容String。

写的挺垃圾，但是几次过后可以直接复制并做略微修改使用了。