优化

app/src/main/res/layout/activity_book_source_edit.xml

@@ -119,6 +119,7 @@
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/recycler_view"
         android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_height="match_parent"
+        tools:listitem="@layout/item_source_edit" />
 
 </LinearLayout>