Flutter内存泄漏检测插件flutter_leak_canary的使用

Flutter内存泄漏检测插件flutter_leak_canary的使用

step 1

首先，需要配置VsCode或Android Studio以设置运行参数--disable-dds。

在VsCode或Android Studio的配置文件中添加以下内容：

"configurations": [
    {
        ...
        "args": [
            "--disable-dds"
        ],
        "type": "dart"
    },
]

或者通过图形界面进行配置：

step 2

接下来，在需要检测内存泄漏的类中添加LeakCanaryStateMixin或LeakCanarySimpleMixin。

class _WeakPageState extends State<WeakPage> with LeakCanaryStateMixin {
  //...
}

class TestModel with LeakCanarySimpleMixin {
  Timer? timer;
  int count = 0;

  init() {
    watch();
    timer = Timer.periodic(Duration(seconds: 1), (timer) {
      count++;
      print("TestModel $count");
    });
  }

  void dispose() {
    timer?.cancel();
    try2Check();
  }
}

示例

以下是一个完整的示例代码，展示了如何使用flutter_leak_canary插件来检测内存泄漏。

import 'dart:isolate';
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:flutter_leak_canary/flutter_leak_canary.dart';
import 'package:flutter_leak_canary/leak_canary_state_mixin.dart';
import 'package:flutter_leak_canary/leak_cannary_model.dart';
import 'package:flutter_leak_canary_example/weak_page.dart';
import 'package:intl/intl.dart';

void main() {
  runApp(_MyApp());
}

class _MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyApp(),
    );
  }
}

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

  [@override](/user/override)
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  [@override](/user/override)
  void initState() {
    super.initState();
    initPlatformState();
    FlutterLeakCanary.get().addListener(_onChange);
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
      Navigator.push(context, MaterialPageRoute(builder: (context) {
        return WeakPage();
      }));
    });
  }

  List<LeakCanaryWeakModel> canaryModels = [];

  _onChange() {
    if (mounted) {
      setState(() {
        canaryModels = FlutterLeakCanary.get().canaryModels;
      });
    }
  }

  [@override](/user/override)
  void dispose() {
    super.dispose();
    FlutterLeakCanary.get().removeListener(_onChange);
  }

  // 平台消息是异步的，因此我们在异步方法中初始化。
  Future<void> initPlatformState() async {
    String platformVersion;
    // 平台消息可能会失败，所以我们使用try/catch处理PlatformException。
    // 我们还处理消息可能返回null的情况。
    try {
      'Unknown platform version';
    } on PlatformException {
      platformVersion = 'Failed to get platform version.';
    }

    // 如果小部件从树中被移除，而异步平台消息还在飞行中，我们希望丢弃回复而不是调用setState更新我们的非存在的外观。
    if (!mounted) return;

    setState(() {});
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('插件示例应用'),
      ),
      body: ListView.builder(
        itemCount: canaryModels.length,
        itemBuilder: (BuildContext context, int index) {
          final canaryModel = canaryModels[index];
          return Container(
            padding: EdgeInsets.symmetric(horizontal: 10),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.start,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                    '${DateFormat("yyyy-MM-dd HH:mm:ss").format(DateTime.fromMillisecondsSinceEpoch(canaryModel.createTime))}'),
                Text('file:${canaryModel.classFileName}', style: TextStyle(color: Colors.lightBlue),),
                Text('class name:${canaryModel.className}', style: TextStyle(color: Colors.red),),
                Text('location>column:${canaryModel.column},line:${canaryModel.line}', style: TextStyle(color: Colors.redAccent),),
                SizedBox(
                  height: 5,
                ),
                Container(
                  width: double.infinity,
                  height: 1,
                  color: Color(0xFFf5f5f5),
                ),
              ],
            ),
          );
        },
      ),
    );
  }
}