安卓:在RecyclerView顶部添加divider

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <size android:height="1dp" />
    <solid android:color="#CCCCCC" />
</shape>

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
    app:itemDecoration="@drawable/divider" />

RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);
recyclerView.addItemDecoration(dividerItemDecoration);