优化

app/src/main/java/io/legado/app/ui/importbook/ImportBookActivity.kt

@@ -15,8 +15,13 @@ import io.legado.app.App
 import io.legado.app.R
 import io.legado.app.base.VMBaseActivity
 import io.legado.app.help.AppConfig
+import io.legado.app.lib.theme.accentColor
 import io.legado.app.utils.getViewModel
 import kotlinx.android.synthetic.main.activity_import_book.*
+import kotlinx.coroutines.Dispatchers.IO
+import kotlinx.coroutines.Dispatchers.Main
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import org.jetbrains.anko.sdk27.listeners.onClick
 import java.io.File
 
@@ -55,6 +60,7 @@ class ImportBookActivity : VMBaseActivity<ImportBookViewModel>(R.layout.activity
         recycler_view.layoutManager = LinearLayoutManager(this)
         importBookAdapter = ImportBookAdapter(this, this)
         recycler_view.adapter = importBookAdapter
+        rotate_loading.loadingColor = accentColor
     }
 
     private fun initEvent() {
@@ -98,7 +104,9 @@ class ImportBookActivity : VMBaseActivity<ImportBookViewModel>(R.layout.activity
             }
             tv_path.text = path
             importBookAdapter.selectedUris.clear()
-
+            importBookAdapter.clearItems()
+            rotate_loading.show()
+            launch(IO) {
                 val docList = arrayListOf<DocumentFile>()
                 lastDoc.listFiles().forEach {
                     if (it.isDirectory && it.name?.startsWith(".") == false) {
@@ -108,9 +116,13 @@ class ImportBookActivity : VMBaseActivity<ImportBookViewModel>(R.layout.activity
                     }
                 }
                 docList.sortWith(compareBy({ !it.isDirectory }, { it.name }))
+                withContext(Main) {
+                    rotate_loading.hide()
                     importBookAdapter.setItems(docList)
                 }
             }
+        }
+    }
 
     private fun selectImportFolder() {
         try {

app/src/main/res/layout/activity_import_book.xml

@@ -50,11 +50,23 @@
             tools:ignore="UnusedAttribute" />
     </LinearLayout>
 
+    <FrameLayout
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1">
+
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/recycler_view"
             android:layout_width="match_parent"
-        android:layout_height="0dp"
-        android:layout_weight="1" />
+            android:layout_height="match_parent" />
+
+        <io.legado.app.ui.widget.anima.RotateLoading
+            android:id="@+id/rotate_loading"
+            android:layout_width="60dp"
+            android:layout_height="60dp"
+            android:layout_gravity="center" />
+
+    </FrameLayout>
 
     <!--文件点击按钮-->
     <RelativeLayout