-从网上找了很多mvvm jetpack的例子，但一直没找到在viewmodel中实现listview的列表项目点击的例子，于是我自己想了个办法。先databinding.enabled=true

构建步骤

1,创建实体类

public class Bean {
    public String userName;
    public Bean(String userName){
        this.userName=userName;
    }
    public void setUserName(String userName) {
        this.userName=userName;
    }
}

2,创建ViewModel

@SuppressLint("StaticFieldLeak")
public class MainVM extends AndroidViewModel {
    Context context;
    private ActivityMainBinding binding;
    public MainVM(@NonNull Application application) {
        super(application);
        context=application;
    }
    public void setBinding(ActivityMainBinding binding){
        this.binding=binding;
        List<Bean> data=new ArrayList<>();
        data.add(new Bean("emm"));
        binding.setAdp(new ListViewAdapter(context,data));
    }
    public static class ListViewAdapter extends ArrayAdapter<Bean> {
        Context context;
        List<Bean> data;
        public ListViewAdapter(Context context, List<Bean> objects){
            super(context,R.layout.item,objects);
            this.context=context;
            data=objects;
        }
        @Override
        public View getView(int position, View convertView, ViewGroup parent){
            ViewDataBinding binding;
            if (convertView == null) {
                binding = DataBindingUtil.inflate(LayoutInflater.from(context), R.layout.item, parent, false);
                convertView = binding.getRoot();
                convertView.setTag(binding);
            } else {
                binding = (ViewDataBinding) convertView.getTag();
            }
            binding.setVariable(BR.adp, data.get(position));
            //还是先用找ID的方法把
            convertView.findViewById(R.id.itemBtn).setOnClickListener(v -> {
                Toast.makeText(context,"123",Toast.LENGTH_SHORT).show();
            });
            return binding.getRoot();
        }
    }
}

3,布局以及Listview列表布局item

• Listview布局: activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <data>
        <variable
            name="adp"
            type="com.demo.MainVM.ListViewAdapter" />
        <variable
            name="vm"
            type="com.demo.MainVM" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <ListView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:adapter="@{adp}"/>
    </LinearLayout>
</layout>

• 列表项目布局: item.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <import type="com.demo.Bean" />
        <variable
            name="user"
            type="com.demo.Bean" />
    </data>
    <LinearLayout
        android:id="@+id/itemBtn"
        android:layout_width="match_parent"
        android:gravity="center"
        android:layout_height="wrap_content"
        android:descendantFocusability="blocksDescendants"
        android:orientation="horizontal">
        <ImageView
            android:src="@mipmap/ic_launcher"
            android:layout_width="100dp"
            android:layout_height="100dp"/>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{`编号：` + user.userName }" />
    </LinearLayout>
</layout>

• 用以记录学习进度，所以有别的解决方案吗，这样虽然可行，但我不太清楚解耦效率如何。