基于dataBinding的万能adapter

先看实现的布局：很简单的一个布局,这里主要是用了一下databinding的数据绑定和事件绑定

Screenshot_SmartSelect_2017-07-19-11-30-37.png

<?xml version="1.0" encoding="utf-8"?>
<layout>

    <data>

        <variable
            name="obj"
            type="com.XXXXXXXX.DataBean"/>

        <variable
            name="event"
            type="com.XXXXXXX.ClickBinding"/>
    </data>

    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:descendantFocusability="blocksDescendants"
        android:gravity="center_vertical"
        android:orientation="horizontal"

        >

        <TextView
            android:id="@+id/title"
            style="@style/text_shimingrenzheng"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_toRightOf="@+id/cb_select"
            android:maxEms="6"
            android:singleLine="true"
            android:text="@{obj.title}"
            android:textSize="14sp"
            />

        <TextView
            style="@style/text_shimingrenzheng"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginLeft="150dp"
            android:maxEms="6"
            android:singleLine="true"
            android:text="@{obj.nickname}"
            android:textColor="#999999"
            android:textSize="12sp"
            />


        <LinearLayout
            android:id="@+id/ll"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:gravity="center_vertical"
            android:orientation="horizontal"
            >

            <ImageView
                android:id="@+id/play_img"
                android:layout_width="14dp"
                android:layout_height="17dp"
                android:layout_marginRight="15dp"
                android:clickable="true"
                android:onClick="@{(view)->event.playOnClick(view,obj)}"
                android:src="@mipmap/play"

                />

            <ImageView
                android:id="@+id/img_dele"
                android:layout_width="17dp"
                android:layout_height="17dp"
                android:layout_marginRight="10dp"
                android:clickable="true"
                android:src="@mipmap/del"
                android:onClick="@{(view)->event.deleOnClick(view,obj)}"
                />
        </LinearLayout>


    </RelativeLayout>
</layout>

封装的adapter：

public abstract class BaseBindingAdapter<T,W extends ViewDataBinding> extends BaseAdapter {
    private List<T> list;
    protected Context context;
    int itemId;
    public BaseBindingAdapter(Context context, List<T> list, int itemId) {
        this.list = list;
        this.context = context;
        this.itemId = itemId;
    }

    public BaseBindingAdapter(Context context) {
        this.context = context;
    }
    public List<T> getList(){
        return this.list;
    }
    public void setList(List<T> list) {
        this.list = list;
        notifyDataSetChanged();
    }
    @Override
    public int getCount() {
        return list == null ? 0 :list.size();
    }
    @Override
    public Object getItem(int position) {
        return list.get(position);
    }
    @Override
    public long getItemId(int position) {
        return position;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        W w;
        if(convertView == null){
            convertView = View.inflate(context,itemId,null);
            w = DataBindingUtil.bind(convertView);
            convertView.setTag(w);
        }
        if (list != null && list.get(position) != null) {
            w = (W) convertView.getTag();
            T t = list.get(position);
            bindObj(w, t);
            operateView(convertView,t);
        }

        return convertView;
    }
    public abstract void bindObj(W w,T t);
    public void operateView(View view, T t){
    }

}

说明：
1、在布局里面绑定事件和数据：

android:text="@{obj.nickname}"
 android:onClick="@{(view)->event.playOnClick(view,obj)}"

2、拓展的方法

//这里可以拿到相应位置的view和data进行其他操作
            @Override
            public void operateView(View view, MusicListBean.DataBean dataBean) {
                super.operateView(view, dataBean);
            }

用法：
1、在写好上面的布局itembinding后，构建一下，会自动生成ItemBinding类
定义全局变量：
BaseBindingAdapter<XXXXX.DataBean, ItemBinding> adapter ;
2、自定义事件，比如这里要实现点击播放和删除：

 public class ClickBinding {
        public void playOnClick(View view, MusicListBean.DataBean dataBean) {
            //播放音乐
        }

        public void deleOnClick(View view, MusicListBean.DataBean dataBean) {
            //删除当前条目
        }
    }

3、创建适配器，传入相应参数，给listView（也可以是gridview之类的）设置adapter

adapter = new BaseBindingAdapter<XXXXX.DataBean, ItemBinding>(this, selectedList, R.layout.itembinding) {

            @Override
            public void bindObj(ItemBinding itemBinding, MusicListBean.DataBean dataBean) {
                               itemBinding.setObj(dataBean);//绑定数据
                               itemBinding.setEvent(new ClickBinding());//绑定事件
                }
            }
        };

        listView.setAdapter(adapter);

4、更新adapter：在请求到服务器数据后：

adapter.setList(list);//list是数据源，setlist方法里面调用了notifyDataSetChanged

·········同样的，用这个adapter实现的其他布局：

Screenshot_SmartSelect_2017-07-19-11-24-25.png image.png