优化

app/src/main/java/io/legado/app/ui/book/info/BookInfoActivity.kt

@@ -59,6 +59,10 @@ class BookInfoActivity :
                         book.durChapterPos = it.second
                         appDb.bookDao.update(book)
                     }
+                    viewModel.chapterListData.value?.let { chapterList ->
+                        binding.tvToc.text =
+                            getString(R.string.toc_s, chapterList[book.durChapterIndex].title)
+                    }
                     startReadActivity(book)
                 }
             }

app/src/main/java/io/legado/app/ui/book/read/ReadBookViewModel.kt

@@ -68,9 +68,7 @@ class ReadBookViewModel(application: Application) : BaseViewModel(application) {
             if (ReadBook.durChapterIndex != book.durChapterIndex) {
                 ReadBook.durChapterIndex = book.durChapterIndex
                 ReadBook.durChapterPos = book.durChapterPos
-                ReadBook.prevTextChapter = null
+                ReadBook.clearTextChapter()
-                ReadBook.curTextChapter = null
-                ReadBook.nextTextChapter = null
             }
             ReadBook.titleDate.postValue(book.name)
             ReadBook.upWebBook(book)