利用Flutter实现移动应用的性能监测配置以及对Flutter监控工具选型的小建议

// 在main.dart中启用调试模式
void main() {
  // 必须开启调试模式才能使用DevTools
  debugPrint = (String? message, {int? wrapWidth}) {
    if (kDebugMode) {
      print(message);
    }
  };
  runApp(MyApp());
}

dependencies:
  firebase_performance: ^0.9.0
  sentry_flutter: ^7.8.0

// FPS监测组件
class FpsMonitor extends StatefulWidget {
  @override
  _FpsMonitorState createState() => _FpsMonitorState();
}

class _FpsMonitorState extends State<FpsMonitor> with WidgetsBindingObserver {
  final fpsNotifier = ValueNotifier<double>(60);
  
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void didChangeMetrics() {
    // 获取帧耗时数据
    final frameTiming = WidgetsBinding.instance!.window.onReportTimings;
    frameTiming?.forEach((List<FrameTiming> timings) {
      final lastFrame = timings.last;
      final fps = 1e9 / lastFrame.totalSpan.inMicroseconds;
      fpsNotifier.value = fps;
    });
  }

  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder<double>(
      valueListenable: fpsNotifier,
      builder: (_, fps, __) {
        // 根据帧率显示颜色提示
        Color color = Colors.green;
        if (fps < 30) color = Colors.red;
        else if (fps < 50) color = Colors.orange;
        return Text('FPS: ${fps.toStringAsFixed(1)}', 
                    style: TextStyle(color: color));
      },
    );
  }
}

// 内存分析工具类
class MemoryProfiler {
  static final _snapshots = <String, int>{};

  static void recordSnapshot(String tag) {
    // 获取当前内存占用
    final current = _getCurrentMemory();
    _snapshots[tag] = current;
  }

  static void compareSnapshot(String tag) {
    final previous = _snapshots[tag];
    final current = _getCurrentMemory();
    if (previous != null) {
      final diff = current - previous;
      debugPrint('内存变化 [$tag]: ${_formatBytes(diff)}');
    }
  }

  static int _getCurrentMemory() {
    // 获取当前进程内存占用
    return ProcessInfo.currentRss;
  }
}

// 使用示例
void openDetailPage() {
  MemoryProfiler.recordSnapshot('before_detail');
  Navigator.push(context, DetailPage());
}

void closeDetailPage() {
  MemoryProfiler.compareSnapshot('before_detail');
}

// 拦截器实现
class NetworkMonitor extends Interceptor {
  final _performance = FirebasePerformance.instance;

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    final trace = _performance.newTrace('network_${options.path}');
    options.extra['perf_trace'] = trace;
    trace.start();
    super.onRequest(options, handler);
  }

  @override
  void onResponse(Response response, ResponseInterceptorHandler handler) {
    final trace = response.requestOptions.extra['perf_trace'] as Trace?;
    trace?.stop();
    _logNetworkMetrics(response, trace);
    super.onResponse(response, handler);
  }

  void _logNetworkMetrics(Response response, Trace? trace) async {
    final metrics = await trace?.getMetrics();
    debugPrint('''
      请求 ${response.requestOptions.path}
      耗时: ${metrics?[HttpMetric.connectionTime]?.value}ms
      数据量: ${response.data.length} bytes
    ''');
  }
}

// 性能基准测试用例
void benchmarkScroll() {
  testWidgets('列表滚动性能测试', (tester) async {
    await tester.pumpWidget(MaterialApp(home: LongListView()));
    
    final stopwatch = Stopwatch()..start();
    await tester.fling(
      find.byType(ListView),
      const Offset(0, -500),
      1000,
    );
    await tester.pumpAndSettle();
    stopwatch.stop();

    expect(stopwatch.elapsedMilliseconds, lessThan(200));
  });
}

// 自动化监控配置示例
void configureMonitoring() {
  FlutterError.onError = (details) {
    FirebaseCrashlytics.instance.recordFlutterError(details);
    Sentry.captureException(details.exception);
  };

  // 每30秒上报性能数据
  Timer.periodic(Duration(seconds: 30), (_) {
    final memory = MemoryProfiler._getCurrentMemory();
    FirebaseAnalytics().logEvent(
      name: 'memory_usage',
      parameters: {'value': memory},
    );
  });
}