如何捕获抽屉的打开和关闭抖动？

Question

如何捕捉抽屉打开和关闭的颤动？原则上，必须使用两个对象来实现此目的：“保存”抽屉的 DrawerController 和抽屉回调。抽屉回调应该跟踪抽屉的打开和关闭，但是https://github.com/flutter/flutter/issues/21272和https://github.com/flutter/flutter/issues/23630中讨论的代码确实如此不行。任何人都可以提供建议吗？

Answer 1

2021 年 12 月更新：

Scaffold(
     drawer: DrawerWidget(),
     onDrawerChanged: (isDrawerOpen) {
          if(isDrawerOpen) {
              //drawer is open
          } else {
              //drawer is close
          }
     },
     body: bodyWidget(),
 )

你可以先在这里参考stackoverflow上其他人的回复

我的解决方案：

获取 DrawerWidget 上的抽屉状态

initState() : open drawer
dispose() : close drawer

通过 DrawerService Provider 流式传输抽屉状态

查看完整代码

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

import 'package:provider/provider.dart';


void main() {
  runApp(
    MultiProvider(
      providers: [
        Provider(create: (_) => DrawerService()),
      ],
      child: MyApp(),
    ),
  );
}

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

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  DrawerService _drawerService;
  String drawerStatus = 'close';
  @override
  void initState() {
    super.initState();
    _drawerService = Provider.of(context, listen: false);
    _listenDrawerService();
  }

  _listenDrawerService() {
    _drawerService.status.listen((status) {
      if(status) {
        drawerStatus = 'open';
      } else {
        drawerStatus = 'close';
      }
      setState(() { });
    });
  }

  @override
  Widget build(BuildContext context) {
    Color bgColor = Colors.yellow;
    if(drawerStatus == 'open') {
      bgColor = Colors.red;
    }

    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      drawer: DrawerWidget(),
      body: Container(
        decoration: BoxDecoration(color: bgColor),
        height: 300,
        child: Center(child: Text(drawerStatus),),
      ),
    );
  }
}


class DrawerWidget extends StatefulWidget {
  @override
  _DrawerWidgetState createState() => _DrawerWidgetState();
}

class _DrawerWidgetState extends State<DrawerWidget> {  
  DrawerService _drawerService;

  @override
  void initState() {
    super.initState();
    _drawerService = Provider.of(context, listen: false);
    _drawerService.setIsOpenStatus(true);
  }

  @override
  Widget build(BuildContext context) {
    return Drawer(
      child: Center(child: Text('drawer'),),
    );
  }

  @override
  void dispose() {
    super.dispose();
    _drawerService.setIsOpenStatus(false);
  }
}

class DrawerService {
  StreamController<bool> _statusController = StreamController.broadcast();
  Stream<bool> get status => _statusController.stream;

  setIsOpenStatus(bool openStatus) {
    _statusController.add(openStatus);
  }
}