8.3 日志与调试

完善的日志体系和错误上报机制是生产级 App 的必备能力，有助于快速定位线上问题。

一、logger 包

dependencies:logger:^2.3.0

import'package:logger/logger.dart';classAppLogger{staticfinalLogger_logger=Logger(printer:PrettyPrinter(methodCount:2,// 显示 2 层调用栈errorMethodCount:8,// 错误时显示 8 层调用栈lineLength:120,colors:true,printEmojis:true,dateTimeFormat:DateTimeFormat.onlyTimeAndSinceStart,),filter:ProductionFilter(),// 生产环境过滤 debug 日志level:AppConfig.isDevelopment?Level.trace:Level.warning,);staticvoidtrace(dynamicmessage,[Object?error,StackTrace?stackTrace])=>_logger.t(message,error:error,stackTrace:stackTrace);staticvoiddebug(dynamicmessage,[Object?error,StackTrace?stackTrace])=>_logger.d(message,error:error,stackTrace:stackTrace);staticvoidinfo(dynamicmessage,[Object?error,StackTrace?stackTrace])=>_logger.i(message,error:error,stackTrace:stackTrace);staticvoidwarning(dynamicmessage,[Object?error,StackTrace?stackTrace])=>_logger.w(message,error:error,stackTrace:stackTrace);staticvoiderror(dynamicmessage,[Object?error,StackTrace?stackTrace])=>_logger.e(message,error:error,stackTrace:stackTrace);staticvoidfatal(dynamicmessage,[Object?error,StackTrace?stackTrace])=>_logger.f(message,error:error,stackTrace:stackTrace);}// 使用AppLogger.info('用户登录成功:${user.name}');AppLogger.error('API 请求失败',e,stackTrace);

二、Sentry 错误上报

dependencies:sentry_flutter:^7.19.0

// main.dartFuture<void>main()async{awaitSentryFlutter.init((options){options.dsn=AppConfig.sentryDsn;options.environment=AppConfig.appEnv;options.release='my_app@1.0.0+1';options.tracesSampleRate=0.2;// 20% 性能追踪options.profilesSampleRate=0.1;// 过滤不需要上报的错误options.beforeSend=(event,hint){if(event.throwableisNetworkException)returnnull;// 不上报网络错误returnevent;};},appRunner:()=>runApp(constMyApp()),);}// 手动上报try{awaitriskyOperation();}catch(e,stackTrace){awaitSentry.captureException(e,stackTrace:stackTrace);// 或附加额外信息awaitSentry.captureException(e,stackTrace:stackTrace,withScope:(scope){scope.setTag('operation','checkout');scope.setExtra('orderId',orderId);scope.setUser(SentryUser(id:currentUser.id.toString()));},);}// 性能追踪Future<void>loadProductList()async{finaltransaction=Sentry.startTransaction('loadProductList','http.client');try{finalproducts=awaitrepository.fetchAll();transaction.status=constSpanStatus.ok();returnproducts;}catch(e){transaction.status=constSpanStatus.internalError();rethrow;}finally{awaittransaction.finish();}}

三、全局异常捕获

Future<void>main()async{// 捕获 Flutter 框架内的错误FlutterError.onError=(details){AppLogger.error('Flutter Error:${details.exception}',details.exception,details.stack,);Sentry.captureException(details.exception,stackTrace:details.stack);};// 捕获 Dart 异步错误（未被 try-catch 捕获的）PlatformDispatcher.instance.onError=(error,stack){AppLogger.fatal('Uncaught Error:$error',error,stack);Sentry.captureException(error,stackTrace:stack);returntrue;// 返回 true 表示已处理};// 确保 Flutter 绑定初始化完成后再捕获错误runApp(constProviderScope(child:MyApp()),);}

四、调试技巧

// 仅在 Debug 模式下执行assert((){print('Debug only:$data');returntrue;}());// kDebugMode / kReleaseMode / kProfileModeif(kDebugMode){print('Debug mode log');}// debugger()：在代码中设置断点（需 Debug 模式）import'dart:developer';debugger(when:condition,message:'Break here');// inspect()：在 DevTools Inspector 中查看对象inspect(myObject);

小结

👉 下一章：九、平台交互（Platform Integration）