fix

lib/pages/library/controller.dart

@@ -332,11 +332,6 @@ class LibraryController extends GetxController with GetTickerProviderStateMixin{
       isFree = selectedFree.id ??'';
     }
 
-    String isFree = '';
-    if (selectedFree.selected == true){
-      isFree = selectedFree.id??'';
-    }
-
     if (isRefresh) _page = 1;
     // 网路请求
     final result = await LibraryAPI.books(