diff --git a/lib/widgets/custom/ordedr_class/order_class_nav/order_class_style.dart b/lib/widgets/custom/ordedr_class/order_class_nav/order_class_style.dart
index cbb02bc..8e0afa6 100644
--- a/lib/widgets/custom/ordedr_class/order_class_nav/order_class_style.dart
+++ b/lib/widgets/custom/ordedr_class/order_class_nav/order_class_style.dart
@@ -129,7 +129,7 @@ class ListStyle {
         this.skipName});
 
   ListStyle.fromJson(Map<String, dynamic> json) {
-    idx = json['idx'];
+    idx = json['idx']?.toString();
     title = json['title'];
     img = json['img'];
     data = json['data'] != null ? new Data.fromJson(json['data']) : null;