ui细节优化

lib/widgets/tabbed_nav_app_bar.dart

@@ -21,8 +21,14 @@ class TabbedNavAppBar {
     EdgeInsetsGeometry? tabLabelPadding,
   }) {
     return AppBar(
-      toolbarHeight: AppConstants.tabbedPageToolbarHeight,
-      title: Text(title, style: const TextStyle(fontWeight: FontWeight.bold)),
+      title: Text(
+        title,
+        style: const TextStyle(
+          fontWeight: FontWeight.bold,
+          fontSize: 18,
+          color: Colors.black87,
+        ),
+      ),
       backgroundColor: Colors.white,
       foregroundColor: Colors.black87,
       iconTheme: const IconThemeData(color: Colors.black87),
@@ -33,34 +39,21 @@ class TabbedNavAppBar {
       centerTitle: true,
       leading: leading,
       actions: actions,
-      // 用 PreferredSize + 固定高度略小于默认 Tab 行，减少两页相同的「标题+Tab」总高度（当前 SDK 无 tabHeight 参数）
-      bottom: PreferredSize(
-        preferredSize: Size.fromHeight(AppConstants.tabbedPageTabBarHeight),
-        child: SizedBox(
-          height: AppConstants.tabbedPageTabBarHeight,
-          child: TabBar(
-            controller: tabController,
-            isScrollable: tabBarScrollable,
-            padding:
-                tabPadding ??
-                (tabBarScrollable
-                    ? const EdgeInsets.only(
-                        left: AppConstants.pageHorizontalPadding,
-                        right: 8,
-                      )
-                    : null),
-            labelPadding: tabLabelPadding,
-            tabAlignment: tabBarScrollable ? TabAlignment.start : null,
-            dividerHeight: 0,
-            dividerColor: Colors.transparent,
-            tabs: tabLabels.map((String e) => Tab(text: e)).toList(),
-            labelColor: AppConstants.primaryColor,
-            unselectedLabelColor: Colors.grey[600],
-            indicatorColor: AppConstants.primaryColor,
-            indicatorWeight: 3,
-            labelStyle: const TextStyle(fontWeight: FontWeight.bold),
-          ),
+      bottom: TabBar(
+        controller: tabController,
+        isScrollable: tabBarScrollable,
+        padding: tabPadding,
+        labelPadding: tabLabelPadding,
+        tabAlignment: tabBarScrollable ? TabAlignment.start : null,
+        dividerHeight: 0,
+        dividerColor: Colors.transparent,
+        tabs: tabLabels.map((String e) => Tab(text: e)).toList(),
+        labelColor: AppConstants.primaryColor,
+        unselectedLabelColor: Colors.grey[600],
+        indicator: UnderlineTabIndicator(
+          borderSide: BorderSide(color: AppConstants.primaryColor, width: 3),
         ),
+        labelStyle: const TextStyle(fontWeight: FontWeight.bold),
       ),
     );
   }