优化

app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceAdapter.kt

@@ -20,11 +20,9 @@ class ChangeSourceAdapter(
     context: Context,
     val viewModel: ChangeSourceViewModel,
     val callBack: CallBack
-) :
-    DiffRecyclerAdapter<SearchBook, ItemChangeSourceBinding>(context) {
+) : DiffRecyclerAdapter<SearchBook, ItemChangeSourceBinding>(context) {
 
-    override val diffItemCallback: DiffUtil.ItemCallback<SearchBook>
-        get() = object : DiffUtil.ItemCallback<SearchBook>() {
+    override val diffItemCallback = object : DiffUtil.ItemCallback<SearchBook>() {
         override fun areItemsTheSame(oldItem: SearchBook, newItem: SearchBook): Boolean {
             return oldItem.bookUrl == newItem.bookUrl
         }

app/src/main/java/io/legado/app/ui/main/bookshelf/style2/BaseBooksAdapter.kt

@@ -11,8 +11,7 @@ abstract class BaseBooksAdapter<VH : RecyclerView.ViewHolder>(
     val callBack: CallBack
 ) : RecyclerView.Adapter<VH>() {
 
-    val diffItemCallback: DiffUtil.ItemCallback<Book>
-        get() = object : DiffUtil.ItemCallback<Book>() {
+    val diffItemCallback = object : DiffUtil.ItemCallback<Book>() {
 
         override fun areItemsTheSame(oldItem: Book, newItem: Book): Boolean {
             return oldItem.name == newItem.name

app/src/main/java/io/legado/app/ui/main/explore/ExploreFragment.kt

@@ -40,6 +40,7 @@ class ExploreFragment : VMBaseFragment<ExploreViewModel>(R.layout.fragment_explo
     private val searchView: SearchView by lazy {
         binding.titleBar.findViewById(R.id.search_view)
     }
+    private val diffItemCallBack = ExploreDiffItemCallBack()
     private val groups = linkedSetOf<String>()
     private var exploreFlowJob: Job? = null
     private var groupsMenu: SubMenu? = null
@@ -127,7 +128,7 @@ class ExploreFragment : VMBaseFragment<ExploreViewModel>(R.layout.fragment_explo
             }
             exploreFlow.collect {
                 binding.tvEmptyMsg.isGone = it.isNotEmpty() || searchView.query.isNotEmpty()
-                adapter.setItems(it, ExploreDiffItemCallBack())
+                adapter.setItems(it, diffItemCallBack)
             }
         }
     }

app/src/main/java/io/legado/app/ui/rss/source/manage/RssSourceAdapter.kt

@@ -36,8 +36,7 @@ class RssSourceAdapter(context: Context, val callBack: CallBack) :
             return selection.sortedBy { it.customOrder }
         }
 
-    val diffItemCallback: DiffUtil.ItemCallback<RssSource>
-        get() = object : DiffUtil.ItemCallback<RssSource>() {
+    val diffItemCallback = object : DiffUtil.ItemCallback<RssSource>() {
 
         override fun areItemsTheSame(oldItem: RssSource, newItem: RssSource): Boolean {
             return oldItem.sourceUrl == newItem.sourceUrl