优化

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

@@ -11,6 +11,9 @@ import io.legado.app.data.entities.Book
 @Dao
 interface BookDao {
 
+    @Query("SELECT * FROM books")
+    fun observeAll(): DataSource.Factory<Int, Book>
+
     @Query("SELECT * FROM books WHERE `group` = :group")
     fun observeByGroup(group: Int): DataSource.Factory<Int, Book>
 

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

@@ -2,10 +2,16 @@ package io.legado.app.ui.bookshelf
 
 import android.os.Bundle
 import android.widget.LinearLayout
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Observer
+import androidx.paging.LivePagedListBuilder
+import androidx.paging.PagedList
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.LinearLayoutManager
+import io.legado.app.App
 import io.legado.app.R
 import io.legado.app.base.BaseActivity
+import io.legado.app.data.entities.Book
 import io.legado.app.utils.getViewModel
 import kotlinx.android.synthetic.main.activity_bookshelf.*
 
@@ -16,6 +22,7 @@ class BookshelfActivity : BaseActivity<BookshelfViewModel>() {
         get() = R.layout.activity_bookshelf
 
     private lateinit var bookshelfAdapter: BookshelfAdapter
+    private var bookshelfLiveData: LiveData<PagedList<Book>>? = null
 
     override fun onViewModelCreated(viewModel: BookshelfViewModel, savedInstanceState: Bundle?) {
         if (viewModel.bookGroup == null) {
@@ -38,7 +45,17 @@ class BookshelfActivity : BaseActivity<BookshelfViewModel>() {
     private fun upRecyclerData() {
         viewModel.bookGroup?.let {
             when (it.groupId) {
-
+                -1 -> {
+                    bookshelfLiveData?.removeObservers(this)
+                    bookshelfLiveData =
+                        LivePagedListBuilder(App.db.bookDao().observeAll(), 10).build()
+                    bookshelfLiveData?.observe(
+                        this,
+                        Observer { pageList -> bookshelfAdapter.submitList(pageList) })
+                }
+                else -> {
+
+                }
             }
         }
     }