DataBind第二篇：RecyclerView Adapter

原文链接：https://www.jianshu.com/p/c219536a940a

相信很多人用的适配器都是目前战力1万7的 BaseRecyclerViewAdapterHelper，没错，我也是用的这把战器。然后我们把这把战器镶嵌一颗DataBind宝石，让其战力更为强大。

1.写一个DataBindBaseViewHolder

public  class DataBindBaseViewHolder extends BaseViewHolder {
    private ViewDataBinding binding;
    public DataBindBaseViewHolder(@NonNull View itemView) {
        super(itemView);
        binding = DataBindingUtil.bind(itemView);
    }
    public ViewDataBinding getBinding() {
        return binding;
    }
}

2.使用：

public class DataBindDemoAdapter extends BaseQuickAdapter<MenuItem,DataBindBaseViewHolder> {
    public DataBindDemoAdapter() {
        super(R.layout.item_binding);
    }
    @Override
    protected void convert(DataBindBaseViewHolder helper, MenuItem item) {
        //这里的ItemBindingBinding就是item_binding去下划线后的骆驼命名+Binding
        ItemBindingBinding binding = (ItemBindingBinding) helper.getBinding();
        binding.setItem(item);
        binding.ivIcon.setImageResource(item.getImgRes());
    }
}

item_binding布局文件：

<?xml version="1.0" encoding="utf-8"?>
<layout>
    <data>
        <variable
            name="item"
            type="com.smallcake.model.MenuItem" />
    </data>
    <android.support.constraint.ConstraintLayout 
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="80dp">
        <ImageView
            android:id="@+id/iv_icon"
            android:layout_width="48dp"
            android:layout_height="48dp"
            android:layout_marginTop="8dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            tools:src="@mipmap/ic_launcher_round" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:text="@{item.title}"
            android:textSize="14sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/iv_icon"
            tools:text="SmallCaek" />
    </android.support.constraint.ConstraintLayout>
</layout>

特点：

• 1.使用DataBind一键设置数据对象数据，不用在适配器中写一堆setText
• 2.xml中不用写id属性，除非你要在适配器代码中使用