content: import 'package:flutter/material.dart';
  
  /// 构建错误提示
  Widget buildCommonErrorWidget({
    String? error,
    VoidCallback? onRetry,
    bool showBack = false,
    BuildContext? context,
  }) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(Icons.error_outline, size: 64, color: Colors.grey[400]),
          const SizedBox(height: 16),
          Text('加载失败', style: TextStyle(fontSize: 18, color: Colors.grey[600])),
          const SizedBox(height: 8),
          Text(
            error ?? '未知错误',
            style: TextStyle(fontSize: 14, color: Colors.grey[500]),
            textAlign: TextAlign.center,
          ),
          const SizedBox(height: 16),
          ElevatedButton(onPressed: onRetry, child: const Text('重试')),
          if (showBack && context != null)
            TextButton(
              onPressed: () => Navigator.pop(context),
              child: const Text('返回'),
            ),
        ],
      ),
    );
  }
  
  /// 构建空数据提示
  Widget buildCommonEmptyWidget({
    IconData? icon,
    String? message,
    String? subMessage,
  }) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(icon ?? Icons.person, size: 64, color: Colors.grey[400]),
          const SizedBox(height: 16),
          Text(
            message ?? '暂无数据',
            style: TextStyle(fontSize: 18, color: Colors.grey[600]),
          ),
          const SizedBox(height: 8),
          Text(
            subMessage ?? '请稍后再试',
            style: TextStyle(fontSize: 14, color: Colors.grey[500]),
          ),
        ],
      ),
    );
  }
  