diff --git a/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceAdapter.kt b/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceAdapter.kt
index ffc51ce84..0da75c27f 100644
--- a/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceAdapter.kt
+++ b/app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceAdapter.kt
@@ -20,22 +20,20 @@ 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 fun areItemsTheSame(oldItem: SearchBook, newItem: SearchBook): Boolean {
-                return oldItem.bookUrl == newItem.bookUrl
-            }
-
-            override fun areContentsTheSame(oldItem: SearchBook, newItem: SearchBook): Boolean {
-                return oldItem.originName == newItem.originName
-                        && oldItem.getDisplayLastChapterTitle() == newItem.getDisplayLastChapterTitle()
-            }
+    override val diffItemCallback = object : DiffUtil.ItemCallback<SearchBook>() {
+        override fun areItemsTheSame(oldItem: SearchBook, newItem: SearchBook): Boolean {
+            return oldItem.bookUrl == newItem.bookUrl
+        }
 
+        override fun areContentsTheSame(oldItem: SearchBook, newItem: SearchBook): Boolean {
+            return oldItem.originName == newItem.originName
+                    && oldItem.getDisplayLastChapterTitle() == newItem.getDisplayLastChapterTitle()
         }
 
+    }
+
     override fun getViewBinding(parent: ViewGroup): ItemChangeSourceBinding {
         return ItemChangeSourceBinding.inflate(inflater, parent, false)
     }
diff --git a/app/src/main/java/io/legado/app/ui/main/bookshelf/style2/BaseBooksAdapter.kt b/app/src/main/java/io/legado/app/ui/main/bookshelf/style2/BaseBooksAdapter.kt
index e5a0428c5..6f3a1f9a9 100644
--- a/app/src/main/java/io/legado/app/ui/main/bookshelf/style2/BaseBooksAdapter.kt
+++ b/app/src/main/java/io/legado/app/ui/main/bookshelf/style2/BaseBooksAdapter.kt
@@ -11,18 +11,17 @@ 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
-                        && oldItem.author == newItem.author
-            }
+        override fun areItemsTheSame(oldItem: Book, newItem: Book): Boolean {
+            return oldItem.name == newItem.name
+                    && oldItem.author == newItem.author
+        }
 
-            override fun areContentsTheSame(oldItem: Book, newItem: Book): Boolean {
-                return when {
-                    oldItem.durChapterTime != newItem.durChapterTime -> false
-                    oldItem.name != newItem.name -> false
+        override fun areContentsTheSame(oldItem: Book, newItem: Book): Boolean {
+            return when {
+                oldItem.durChapterTime != newItem.durChapterTime -> false
+                oldItem.name != newItem.name -> false
                     oldItem.author != newItem.author -> false
                     oldItem.durChapterTitle != newItem.durChapterTitle -> false
                     oldItem.latestChapterTitle != newItem.latestChapterTitle -> false
diff --git a/app/src/main/java/io/legado/app/ui/main/explore/ExploreFragment.kt b/app/src/main/java/io/legado/app/ui/main/explore/ExploreFragment.kt
index 80ccfef1d..7c321c9ca 100644
--- a/app/src/main/java/io/legado/app/ui/main/explore/ExploreFragment.kt
+++ b/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)
             }
         }
     }
diff --git a/app/src/main/java/io/legado/app/ui/rss/source/manage/RssSourceAdapter.kt b/app/src/main/java/io/legado/app/ui/rss/source/manage/RssSourceAdapter.kt
index 42f7a4c67..34147a14c 100644
--- a/app/src/main/java/io/legado/app/ui/rss/source/manage/RssSourceAdapter.kt
+++ b/app/src/main/java/io/legado/app/ui/rss/source/manage/RssSourceAdapter.kt
@@ -36,18 +36,17 @@ 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
-            }
+        override fun areItemsTheSame(oldItem: RssSource, newItem: RssSource): Boolean {
+            return oldItem.sourceUrl == newItem.sourceUrl
+        }
 
-            override fun areContentsTheSame(oldItem: RssSource, newItem: RssSource): Boolean {
-                return oldItem.sourceName == newItem.sourceName
-                        && oldItem.sourceGroup == newItem.sourceGroup
-                        && oldItem.enabled == newItem.enabled
-            }
+        override fun areContentsTheSame(oldItem: RssSource, newItem: RssSource): Boolean {
+            return oldItem.sourceName == newItem.sourceName
+                    && oldItem.sourceGroup == newItem.sourceGroup
+                    && oldItem.enabled == newItem.enabled
+        }
 
             override fun getChangePayload(oldItem: RssSource, newItem: RssSource): Any? {
                 val payload = Bundle()