优化

app/src/main/java/io/legado/app/data/dao/BookGroupDao.kt

@@ -1,5 +1,6 @@
 package io.legado.app.data.dao
 
+import androidx.lifecycle.LiveData
 import androidx.room.*
 import io.legado.app.constant.BookType
 import io.legado.app.data.entities.BookGroup
@@ -26,7 +27,7 @@ interface BookGroupDao {
         or (groupId = -1 and show > 0)
         ORDER BY `order`"""
     )
-    val show: Flow<List<BookGroup>>
+    val show: LiveData<List<BookGroup>>
 
     @Query("SELECT * FROM book_groups where groupId >= 0 ORDER BY `order`")
     fun flowSelect(): Flow<List<BookGroup>>

app/src/main/java/io/legado/app/ui/main/bookshelf/BaseBookshelfFragment.kt

@@ -5,11 +5,14 @@ import android.view.Menu
 import android.view.MenuItem
 import androidx.fragment.app.activityViewModels
 import androidx.fragment.app.viewModels
+import androidx.lifecycle.LiveData
 import io.legado.app.R
 import io.legado.app.base.VMBaseFragment
 import io.legado.app.constant.EventBus
 import io.legado.app.constant.PreferKey
+import io.legado.app.data.appDb
 import io.legado.app.data.entities.Book
+import io.legado.app.data.entities.BookGroup
 import io.legado.app.databinding.DialogBookshelfConfigBinding
 import io.legado.app.databinding.DialogEditTextBinding
 import io.legado.app.help.AppConfig
@@ -60,6 +63,7 @@ abstract class BaseBookshelfFragment(layoutId: Int) : VMBaseFragment<BookshelfVi
     }
     abstract val groupId: Long
     abstract val books: List<Book>
+    private var groupsLiveData: LiveData<List<BookGroup>>? = null
 
     abstract fun gotoTop()
 
@@ -93,6 +97,17 @@ abstract class BaseBookshelfFragment(layoutId: Int) : VMBaseFragment<BookshelfVi
         }
     }
 
+    protected fun initBookGroupData() {
+        groupsLiveData?.removeObservers(viewLifecycleOwner)
+        groupsLiveData = appDb.bookGroupDao.show.apply {
+            observe(viewLifecycleOwner) {
+                upGroup(it)
+            }
+        }
+    }
+
+    abstract fun upGroup(data: List<BookGroup>)
+
     @SuppressLint("InflateParams")
     fun addBookByUrl() {
         alert(titleResource = R.string.add_book_url) {

app/src/main/java/io/legado/app/ui/main/bookshelf/style1/BookshelfFragment1.kt

@@ -27,9 +27,6 @@ import io.legado.app.utils.putPrefInt
 import io.legado.app.utils.setEdgeEffectColor
 import io.legado.app.utils.toastOnUi
 import io.legado.app.utils.viewbindingdelegate.viewBinding
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.flow.collect
-import kotlinx.coroutines.launch
 
 /**
  * 书架界面
@@ -45,7 +42,6 @@ class BookshelfFragment1 : BaseBookshelfFragment(R.layout.fragment_bookshelf),
     }
     private val bookGroups = mutableListOf<BookGroup>()
     private val fragmentMap = hashMapOf<Long, BooksFragment>()
-    private var groupsFlowJob: Job? = null
     override val groupId: Long get() = selectedGroup?.groupId ?: 0
 
     override val books: List<Book>
@@ -73,15 +69,6 @@ class BookshelfFragment1 : BaseBookshelfFragment(R.layout.fragment_bookshelf),
         binding.viewPagerBookshelf.adapter = adapter
     }
 
-    private fun initBookGroupData() {
-        groupsFlowJob?.cancel()
-        groupsFlowJob = launch {
-            appDb.bookGroupDao.show.collect {
-                upGroup(it)
-            }
-        }
-    }
-
     override fun onQueryTextSubmit(query: String?): Boolean {
         SearchActivity.start(requireContext(), query)
         return false
@@ -92,7 +79,7 @@ class BookshelfFragment1 : BaseBookshelfFragment(R.layout.fragment_bookshelf),
     }
 
     @Synchronized
-    private fun upGroup(data: List<BookGroup>) {
+    override fun upGroup(data: List<BookGroup>) {
         if (data.isEmpty()) {
             appDb.bookGroupDao.enableGroup(AppConst.bookGroupAllId)
         } else {

app/src/main/java/io/legado/app/ui/main/bookshelf/style2/BookshelfFragment2.kt

@@ -52,7 +52,6 @@ class BookshelfFragment2 : BaseBookshelfFragment(R.layout.fragment_bookshelf1),
         }
     }
     private var bookGroups: List<BookGroup> = emptyList()
-    private var groupsFlowJob: Job? = null
     private var booksFlowJob: Job? = null
     override var groupId = AppConst.bookGroupNoneId
     override var books: List<Book> = emptyList()
@@ -60,7 +59,7 @@ class BookshelfFragment2 : BaseBookshelfFragment(R.layout.fragment_bookshelf1),
     override fun onFragmentCreated(view: View, savedInstanceState: Bundle?) {
         setSupportToolbar(binding.titleBar.toolbar)
         initRecyclerView()
-        initGroupData()
+        initBookGroupData()
         initBooksData()
     }
 
@@ -97,18 +96,13 @@ class BookshelfFragment2 : BaseBookshelfFragment(R.layout.fragment_bookshelf1),
     }
 
     @SuppressLint("NotifyDataSetChanged")
-    private fun initGroupData() {
+    override fun upGroup(data: List<BookGroup>) {
-        groupsFlowJob?.cancel()
+        if (data != bookGroups) {
-        groupsFlowJob = launch {
+            bookGroups = data
-            appDb.bookGroupDao.show.collect {
-                if (it != bookGroups) {
-                    bookGroups = it
             booksAdapter.notifyDataSetChanged()
             binding.tvEmptyMsg.isGone = getItemCount() > 0
         }
     }
-        }
-    }
 
     @SuppressLint("NotifyDataSetChanged")
     private fun initBooksData() {