Flutter日志管理插件flutter_loggy的使用

简介

Loggy 是一个用于Flutter的日志管理库，它可以帮助开发者更方便地记录和查看应用运行时的日志信息。通过 flutter_loggy 扩展，我们可以更好地集成 Loggy 到我们的Flutter项目中，并且提供了更加丰富的功能。

安装与配置

添加依赖

首先，在你的 pubspec.yaml 文件中添加 flutter_loggy 和 loggy 的依赖：

dependencies:
  flutter_loggy: ^latest_version
  loggy: ^latest_version

然后运行 flutter pub get 来安装这些包。

初始化 Loggy

在你的应用程序入口文件（通常是 main.dart）中初始化 Loggy：

import 'package:flutter/material.dart';
import 'package:flutter_loggy/flutter_loggy.dart';
import 'package:loggy/loggy.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();

  Loggy.initLoggy(
    logPrinter: StreamPrinter(const PrettyDeveloperPrinter()),
    logOptions: const LogOptions(
      LogLevel.all,
      stackTraceLevel: LogLevel.error,
    ),
  );

  runApp(const MyApp());
}

这段代码设置了日志打印机为 StreamPrinter 并使用了美观的开发人员打印格式 PrettyDeveloperPrinter。同时，我们设置日志级别为 LogLevel.all，并且只有错误级别的日志会包含堆栈跟踪信息。

使用示例

接下来是一个完整的例子，展示了如何在Flutter应用中使用 flutter_loggy。

示例代码

import 'package:flutter/material.dart';
import 'package:flutter_loggy/flutter_loggy.dart';
import 'package:loggy/loggy.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();

  Loggy.initLoggy(
    logPrinter: StreamPrinter(const PrettyDeveloperPrinter()),
    logOptions: const LogOptions(
      LogLevel.all,
      stackTraceLevel: LogLevel.error,
    ),
  );

  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({
    super.key,
    required this.title,
  });

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with UiLoggy {
  late CounterLogic _counter;

  @override
  void initState() {
    super.initState();
    loggy.debug('Init state called!');
    _counter = CounterLogic(0);
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    loggy.debug('Did change dependencies called!');
  }

  void _click({bool increase = true}) {
    loggy.info('Button clicked!');

    setState(() {
      if (increase) {
        _counter.increment();
      } else {
        _counter.decrement();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    loggy.debug('Build called!');
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Column(
        children: [
          Expanded(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                const Text('You have pushed the button this many times:'),
                Text(
                  '${_counter.value}',
                  style: Theme.of(context).textTheme.headlineMedium,
                ),
              ],
            ),
          ),
        ],
      ),
      floatingActionButton: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          FloatingActionButton(
            onPressed: _click,
            heroTag: 'increment_tag',
            tooltip: 'Increment',
            child: const Icon(Icons.add),
          ),
          const SizedBox(height: 12.0),
          FloatingActionButton(
            onPressed: () => _click(increase: false),
            tooltip: 'Decrement',
            heroTag: 'decrement_tag',
            child: const Icon(Icons.remove),
          ),
        ],
      ),
    );
  }
}

mixin LogicLoggy implements LoggyType {
  @override
  Loggy<LogicLoggy> get loggy => Loggy<LogicLoggy>('Logic($runtimeType)');
}

class CounterLogic with LogicLoggy {
  CounterLogic(this._counter) {
    loggy.debug('Started new counter! Start count value is: $_counter');
  }

  int _counter;

  int get value => _counter;

  void increment() {
    loggy.info('Incrementing counter! Current value: $_counter');

    if (_counter > 2) {
      loggy.debug(
          'Counter is over 2! This is really long message: Lorem Ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.');
    }

    _counter++;
  }

  void decrement() {
    loggy.warning('Decrementing counter! Current value: $_counter');

    if (_counter == 0) {
      loggy.error('Counter is at 0. Counter should never be below 0');
      return;
    }

    _counter--;
  }
}

在这个例子中，我们创建了一个简单的计数器应用。每当用户点击加号或减号按钮时，都会触发相应的日志记录。此外，我们在生命周期方法（如 initState 和 didChangeDependencies）中也添加了日志输出。

总结

通过 flutter_loggy 插件，我们可以非常方便地在Flutter项目中进行日志管理。无论是调试还是监控应用行为，它都提供了一种简单而强大的方式来帮助我们更好地理解应用程序的内部工作流程。希望这个指南能够帮助你快速上手并充分利用 flutter_loggy 的功能！