diff --git a/example/lib/main.dart b/example/lib/main.dart
index 2b1aaeb..dff1d9d 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -3,7 +3,6 @@ import 'package:example/main_extention.dart';
 import 'package:example/main_home.dart';
 import 'package:example/main_utils.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:get/get.dart';
 import 'package:flutter_screenutil/flutter_screenutil.dart';
diff --git a/lib/ansu_ui.dart b/lib/ansu_ui.dart
index 202bfc0..6469499 100644
--- a/lib/ansu_ui.dart
+++ b/lib/ansu_ui.dart
@@ -76,3 +76,4 @@ export 'theme/as_theme.dart';
 
 //third party
 export 'package:velocity_x/velocity_x.dart';
+export 'package:flutter_screenutil/flutter_screenutil.dart';
diff --git a/lib/dialog/as_bottom_dialog.dart b/lib/dialog/as_bottom_dialog.dart
index 7b43cfa..f98c481 100644
--- a/lib/dialog/as_bottom_dialog.dart
+++ b/lib/dialog/as_bottom_dialog.dart
@@ -32,7 +32,7 @@ class ASBottomDialog extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.stretch,
         mainAxisSize: MainAxisSize.min,
         children: [
-          ...items.sepWidget(separate: ASDivider())!,
+          ...(items??[]).sepWidget(separate: ASDivider()),
           10.hb,
           _buildCancel(context),
         ],
diff --git a/lib/dialog/as_dialog.dart b/lib/dialog/as_dialog.dart
index eaaeac5..a157652 100644
--- a/lib/dialog/as_dialog.dart
+++ b/lib/dialog/as_dialog.dart
@@ -73,8 +73,8 @@ class ASDialog extends StatelessWidget {
                         ),
                       ),
                     ),
-                    ...items
-                        .sepWidget(separate: SizedBox(height: _widgetSpacer))!,
+                    ...(items ?? [])
+                        .sepWidget(separate: SizedBox(height: _widgetSpacer)),
                   ],
                 ),
               ),
diff --git a/lib/extension/list_extension.dart b/lib/extension/list_extension.dart
index d9b2fdb..c3e8b86 100644
--- a/lib/extension/list_extension.dart
+++ b/lib/extension/list_extension.dart
@@ -1,13 +1,12 @@
 import 'package:flutter/material.dart';
 import 'package:ansu_ui/extension/num_extension.dart';
 
-extension SeparateExt on List<Widget>? {
-  List<Widget>? sepWidget({Widget? separate}) {
-    if (this == null) return null;
-    if (this!.isEmpty) return [];
-    return List.generate(this!.length * 2 - 1, (index) {
+extension SeparateExt on List<Widget> {
+  List<Widget> sepWidget({Widget? separate}) {
+    if (this.isEmpty) return [];
+    return List.generate(this.length * 2 - 1, (index) {
       if (index.isEven)
-        return this![index ~/ 2];
+        return this[index ~/ 2];
       else
         return separate ?? 10.wb;
     });
diff --git a/lib/list_tile/as_card_expandable.dart b/lib/list_tile/as_card_expandable.dart
index 289f444..386881d 100644
--- a/lib/list_tile/as_card_expandable.dart
+++ b/lib/list_tile/as_card_expandable.dart
@@ -109,14 +109,14 @@ class _ASCardExpandableState extends State<ASCardExpandable> {
           children: [
             SizedBox(),
             ...widget.children,
-          ].sepWidget(separate: ASDivider(indent: 10.w, endIndent: 10.w))!,
+          ].sepWidget(separate: ASDivider(indent: 10.w, endIndent: 10.w)),
         ),
         expanded: Column(
           children: [
             SizedBox(),
             ...(widget.custom ? <Widget>[] : widget.children),
             ...widget.extra,
-          ].sepWidget(separate: ASDivider(indent: 10.w, endIndent: 10.w))!,
+          ].sepWidget(separate: ASDivider(indent: 10.w, endIndent: 10.w)),
         ),
       ),
     );
diff --git a/lib/theme/as_theme.dart b/lib/theme/as_theme.dart
index c3e470a..d8594d9 100644
--- a/lib/theme/as_theme.dart
+++ b/lib/theme/as_theme.dart
@@ -23,6 +23,7 @@ class ASTheme {
         textTheme: ThemeData.light().textTheme.apply(
               displayColor: Color(0xFF333333),
               bodyColor: Color(0xFF333333),
+              fontFamily: 'NotoSansSC',
             ),
         inputDecorationTheme: InputDecorationTheme(),
         primaryColor: kPrimaryColor,
diff --git a/lib/utils/camera_view.dart b/lib/utils/camera_view.dart
index 66c6593..ac91937 100644
--- a/lib/utils/camera_view.dart
+++ b/lib/utils/camera_view.dart
@@ -86,7 +86,7 @@ class _CameraViewState extends State<CameraView> {
               title: '确认',
               onPressed: () => Navigator.pop(context, widget.file),
             ),
-          ].sepWidget(separate: ASDivider())!,
+          ].sepWidget(separate: ASDivider()),
         ),
       ),
     );