优化机器状态无数据显示

lib/features/home/presentation/pages/running_status_page.dart

@@ -241,6 +241,20 @@ class _RunningStatusPageState extends State<RunningStatusPage> {
     );
   }
 
+  // 新增：暂无数据占位组件
+  Widget _noDataWidget() {
+    return Center(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Icon(Icons.inbox_outlined, color: Colors.grey, size: 48),
+          SizedBox(height: 16),
+          Text('暂无数据', style: TextStyle(color: Colors.grey, fontSize: 16)),
+        ],
+      ),
+    );
+  }
+
   Widget _styledLineChart({
     required String title,
     required List<LineChartBarData> lines,
@@ -418,18 +432,13 @@ class _RunningStatusPageState extends State<RunningStatusPage> {
 
   // ====================== 图表视图 ======================
   Widget _buildChartContentView(DeviceStatusState state) {
-    // 新增：如果数据超时，直接显示loading
-    if (_isDataTimeout) {
-      return const Center(child: CircularProgressIndicator(color: Color(0xFF1677FF), strokeWidth: 4));
+    // 修改1：超时/无数据时显示暂无数据，而非loading
+    if (_isDataTimeout || state is DeviceStatusInitial) {
+      return _noDataWidget();
     }
 
     if (state is! DeviceStatusUpdated) {
-      return const Center(
-        child: CircularProgressIndicator(
-          color: Color(0xFF1677FF), // 统一使用项目主题蓝色
-          strokeWidth: 4, // 加粗加载圈，视觉更清晰
-        ),
-      );
+      return _noDataWidget();
     }
 
     final status = state.status;
@@ -650,9 +659,9 @@ class _RunningStatusPageState extends State<RunningStatusPage> {
 
   // ====================== 卡片视图 ======================
   Widget _buildCardContentView(DeviceStatusState state) {
-    // 新增：如果数据超时，直接显示loading
-    if (_isDataTimeout) {
-      return const Center(child: CircularProgressIndicator(color: Color(0xFF1677FF), strokeWidth: 4));
+    // 修改2：卡片视图同样替换loading为暂无数据
+    if (_isDataTimeout || state is DeviceStatusInitial) {
+      return _noDataWidget();
     }
 
     if (state is DeviceStatusUpdated) {
@@ -661,16 +670,9 @@ class _RunningStatusPageState extends State<RunningStatusPage> {
         child: Column(children: [_buildMotorTable(state), const SizedBox(height: 20), _buildOtherParamsTable(state)]),
       );
     } else if (state is DeviceStatusError) {
-      return const Center(
-        child: Text("数据加载失败", style: TextStyle(color: Colors.red, fontSize: 16)),
-      );
+      return _noDataWidget();
     } else {
-      return const Center(
-        child: CircularProgressIndicator(
-          color: Color(0xFF1677FF), // 统一使用项目主题蓝色
-          strokeWidth: 4, // 加粗加载圈，视觉更清晰
-        ),
-      );
+      return _noDataWidget();
     }
   }
 
@@ -794,29 +796,20 @@ class _RunningStatusPageState extends State<RunningStatusPage> {
     final currentDevice = deviceState.selectedDevice;
 
     if (currentDevice == null) {
-      return const Scaffold(body: Center(child: Text("加载中...")));
+      // 修改3：无设备时也显示暂无数据
+      return Scaffold(
+        backgroundColor: const Color(0xFFF7F7F7),
+        appBar: _buildOptimizedAppBar(), // 使用优化后的AppBar
+        body: _noDataWidget(),
+      );
     }
 
     return Scaffold(
       backgroundColor: const Color(0xFFF7F7F7),
+      appBar: _buildOptimizedAppBar(), // 替换原有的SliverAppBar为优化后的AppBar
       body: CustomScrollView(
         physics: const BouncingScrollPhysics(),
         slivers: [
-          SliverAppBar(
-            backgroundColor: const Color(0xFF1677FF),
-            pinned: true,
-            centerTitle: true,
-            elevation: 0,
-            title: const Text(
-              "设备数据监控",
-              style: TextStyle(color: Colors.white, fontSize: 18, fontWeight: FontWeight.bold),
-            ),
-            leading: IconButton(
-              icon: const Icon(Icons.arrow_back, color: Colors.white),
-              onPressed: () => Navigator.pop(context),
-            ),
-          ),
-
           BlocBuilder<DeviceStatusBloc, DeviceStatusState>(
             builder: (context, state) {
               // 新增：超时状态下显示--
@@ -946,6 +939,34 @@ class _RunningStatusPageState extends State<RunningStatusPage> {
     );
   }
 
+  // 修改4：优化后的AppBar样式
+  AppBar _buildOptimizedAppBar() {
+    return AppBar(
+      backgroundColor: const Color(0xFF1677FF),
+      elevation: 4, // 增加阴影，提升层次感
+      centerTitle: true,
+      title: const Text(
+        "设备数据监控",
+        style: TextStyle(
+          color: Colors.white,
+          fontSize: 18,
+          fontWeight: FontWeight.bold,
+          letterSpacing: 0.5, // 增加字间距，提升可读性
+        ),
+      ),
+      leading: IconButton(
+        icon: const Icon(Icons.arrow_back_ios, color: Colors.white, size: 20), // 替换为更精致的ios风格返回图标
+        onPressed: () => Navigator.pop(context),
+        splashRadius: 24, // 优化点击反馈范围
+      ),
+      // 新增：AppBar底部阴影优化
+      shadowColor: Colors.black12,
+      shape: const RoundedRectangleBorder(
+        borderRadius: BorderRadius.only(bottomLeft: Radius.circular(12), bottomRight: Radius.circular(12)),
+      ),
+    );
+  }
+
   // 新增：清空图表历史数据
   void _resetChartData() {
     _leftMeasureHistory.clear();