feat: 优化代码

app/src/main/java/io/legado/app/ui/book/search/SearchActivity.kt

@@ -283,11 +283,12 @@ class SearchActivity : VMBaseActivity<SearchViewModel>(R.layout.activity_book_se
      */
     @Synchronized
     private fun upSearchItems(items: List<SearchBook>, isMandatoryUpdate: Boolean) {
+        val searchItems = ArrayList(items)
         if (isMandatoryUpdate || System.currentTimeMillis() - refreshTime > 500) {
             refreshTime = System.currentTimeMillis()
             val diffResult =
-                DiffUtil.calculateDiff(DiffCallBack(ArrayList(adapter.getItems()), items))
-            adapter.setItems(items, diffResult)
+                DiffUtil.calculateDiff(DiffCallBack(adapter.getItems(), searchItems))
+            adapter.setItems(searchItems, diffResult)
         }
     }