Flutter资源自动释放插件easy_dispose

Flutter资源自动释放插件easy_dispose_flutter的使用

在Flutter开发过程中，管理资源的生命周期是一个重要的任务。easy_dispose_flutter 插件可以帮助我们更方便地管理和释放这些资源。本文将详细介绍如何使用 easy_dispose_flutter 插件，并通过一个完整的示例来展示其用法。

支持的功能

easy_dispose_flutter 插件支持以下功能：

ChangeNotifier监听器
WidgetBinding观察者
FocusNode
ScrollController
TextEditingController
TabController

示例代码

下面是一个完整的示例，展示了如何使用 easy_dispose_flutter 插件来管理资源的生命周期。

import 'dart:async';

import 'package:easy_dispose/easy_dispose.dart';
import 'package:easy_dispose_flutter/easy_dispose_flutter.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

// ignore_for_file: no-empty-block, avoid_print, public_member_api_docs
Future<void> main() async {
  runApp(
    const MaterialApp(
      home: HomeWidget(),
    ),
  );
}

class HomeWidget extends StatefulWidget {
  @override
  _HomeWidgetState createState() => _HomeWidgetState();

  const HomeWidget({
    Key? key,
  }) : super(key: key);
}

class _HomeWidgetState extends State<HomeWidget> with TickerProviderStateMixin {
  late MyDisposableOwner? _myDisposableOwner;

  @override
  void initState() {
    super.initState();
    _myDisposableOwner = MyDisposableOwner(tickerProvider: this);
  }

  @override
  void dispose() {
    super.dispose();
    _myDisposableOwner?.dispose();
  }

  @override
  Widget build(BuildContext context) => const Text('Hello world');
}

class MyDisposableOwner extends DisposableOwner {
  final TextEditingController textEditingController = TextEditingController();
  final ScrollController scrollController = ScrollController();
  final FocusNode focusNode = FocusNode();
  final TabController tabController;

  MyDisposableOwner({
    required TickerProvider tickerProvider,
  })  : tabController = TabController(
          length: 1,
          vsync: tickerProvider,
        ),
        super(
          disposeOrder: DisposeOrder.lifo,
        ) {
    addCustomDisposable(() => print('Final dispose'));

    textEditingController.disposeWith(this);
    scrollController.disposeWith(this);
    focusNode.disposeWith(this);
    tabController.disposeWith(this);

    textEditingController.listenAsDisposable((text) {
      // textEditingController changed
    }).disposeWith(this);
    scrollController.addListener(() {
      // scrollController changed
    }).disposeWith(this);
    focusNode.addListener(() {
      // focusNode changed
    }).disposeWith(this);
    tabController.addListener(() {
      // tabController changed
    }).disposeWith(this);

    WidgetsBinding.instance!.addObserver(
      LifecycleEventHandler(
        (appLifecycleState) {
          // appLifecycleState changed
        },
      ).disposeWith(this),
    );

    addCustomDisposable(() => print('First dispose'));
  }
}

class LifecycleEventHandler extends WidgetsBindingObserver {
  final Function(AppLifecycleState appLifecycleState) callback;

  LifecycleEventHandler(this.callback);

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    callback(state);
  }
}

代码解释

导入必要的库

import 'package:easy_dispose/easy_dispose.dart';
import 'package:easy_dispose_flutter/easy_dispose_flutter.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

定义主函数

Future<void> main() async {
  runApp(
    const MaterialApp(
      home: HomeWidget(),
    ),
  );
}

定义HomeWidget

class HomeWidget extends StatefulWidget {
  @override
  _HomeWidgetState createState() => _HomeWidgetState();

  const HomeWidget({
    Key? key,
  }) : super(key: key);
}

定义_HomeWidgetState

class _HomeWidgetState extends State<HomeWidget> with TickerProviderStateMixin {
  late MyDisposableOwner? _myDisposableOwner;

  @override
  void initState() {
    super.initState();
    _myDisposableOwner = MyDisposableOwner(tickerProvider: this);
  }

  @override
  void dispose() {
    super.dispose();
    _myDisposableOwner?.dispose();
  }

  @override
  Widget build(BuildContext context) => const Text('Hello world');
}

定义MyDisposableOwner类

class MyDisposableOwner extends DisposableOwner {
  final TextEditingController textEditingController = TextEditingController();
  final ScrollController scrollController = ScrollController();
  final FocusNode focusNode = FocusNode();
  final TabController tabController;

  MyDisposableOwner({
    required TickerProvider tickerProvider,
  })  : tabController = TabController(
        length: 1,
        vsync: tickerProvider,
      ),
      super(
        disposeOrder: DisposeOrder.lifo,
      ) {
    addCustomDisposable(() => print('Final dispose'));

    textEditingController.disposeWith(this);
    scrollController.disposeWith(this);
    focusNode.disposeWith(this);
    tabController.disposeWith(this);

    textEditingController.listenAsDisposable((text) {
      // textEditingController changed
    }).disposeWith(this);
    scrollController.addListener(() {
      // scrollController changed
    }).disposeWith(this);
    focusNode.addListener(() {
      // focusNode changed
    }).disposeWith(this);
    tabController.addListener(() {
      // tabController changed
    }).disposeWith(this);

    WidgetsBinding.instance!.addObserver(
      LifecycleEventHandler(
        (appLifecycleState) {
          // appLifecycleState changed
        },
      ).disposeWith(this),
    );

    addCustomDisposable(() => print('First dispose'));
  }
}

定义LifecycleEventHandler类

class LifecycleEventHandler extends WidgetsBindingObserver {
  final Function(AppLifecycleState appLifecycleState) callback;

  LifecycleEventHandler(this.callback);

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    callback(state);
  }
}

更多关于Flutter资源自动释放插件easy_dispose_flutter的使用的实战教程也可以访问 https://www.itying.com/category-92-b0.html

caililin 1楼

更多关于Flutter资源自动释放插件easy_dispose_flutter的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html

easy_dispose_flutter 是一个用于 Flutter 的资源自动释放插件，它可以帮助开发者更方便地管理 Flutter 应用中的资源释放问题。该插件基于 disposable 库，提供了一种简单的方式来确保在 Widget 销毁时自动释放相关资源。

1. 安装插件

首先，你需要在 pubspec.yaml 文件中添加 easy_dispose_flutter 依赖：

dependencies:
  flutter:
    sdk: flutter
  easy_dispose_flutter: ^latest_version

然后运行 flutter pub get 来安装依赖。

2. 使用 `DisposableWidget`

easy_dispose_flutter 提供了 DisposableWidget 类，你可以通过继承它来管理资源的释放。

import 'package:flutter/material.dart';
import 'package:easy_dispose_flutter/easy_dispose_flutter.dart';

class MyDisposableWidget extends DisposableWidget {
  [@override](/user/override)
  void dispose() {
    // 在这里释放资源
    super.dispose();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Container(
      child: Text('My Disposable Widget'),
    );
  }
}

在 dispose 方法中，你可以释放任何需要在 Widget 销毁时释放的资源。

3. 使用 `DisposableProvider`

DisposableProvider 是一个 InheritedWidget，它可以在 Widget 树中提供 Disposable 对象，并确保在 Widget 销毁时自动释放资源。

import 'package:flutter/material.dart';
import 'package:easy_dispose_flutter/easy_dispose_flutter.dart';

class MyDisposableObject implements Disposable {
  [@override](/user/override)
  void dispose() {
    // 释放资源
  }
}

class MyWidget extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return DisposableProvider(
      create: (context) => MyDisposableObject(),
      child: Builder(
        builder: (context) {
          final disposable = DisposableProvider.of<MyDisposableObject>(context);
          return Container(
            child: Text('Using DisposableProvider'),
          );
        },
      ),
    );
  }
}

在这个例子中，MyDisposableObject 会在 MyWidget 销毁时自动释放。

4. 使用 `DisposableBuilder`

DisposableBuilder 是一个 StatefulWidget，它允许你在 initState 和 dispose 中管理资源。

import 'package:flutter/material.dart';
import 'package:easy_dispose_flutter/easy_dispose_flutter.dart';

class MyDisposableBuilderWidget extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return DisposableBuilder(
      init: (context) {
        // 初始化资源
      },
      dispose: (context) {
        // 释放资源
      },
      child: Container(
        child: Text('Using DisposableBuilder'),
      ),
    );
  }
}

5. 使用 `DisposableMixin`

如果你不想继承 DisposableWidget，你可以使用 DisposableMixin 来混入到你的 State 类中。

import 'package:flutter/material.dart';
import 'package:easy_dispose_flutter/easy_dispose_flutter.dart';

class MyStatefulWidget extends StatefulWidget {
  [@override](/user/override)
  _MyStatefulWidgetState createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> with DisposableMixin {
  [@override](/user/override)
  void initState() {
    super.initState();
    // 初始化资源
  }

  [@override](/user/override)
  void dispose() {
    // 释放资源
    super.dispose();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Container(
      child: Text('Using DisposableMixin'),
    );
  }
}

Flutter资源自动释放插件easy_dispose_flutter的使用