flutter - 出现异常。 FlutterError (setState() 在 dispose() : _MyProfileState#c3ad1(lifecycle state: defunct, 未安装后调用)

Question

当我单击从个人资料页面到通知的通知导航项时显示此错误

Exception has occurred. FlutterError (setState() called afterdispose(): _MyProfileState#c3ad1(lifecycle state: defunct, notmounted) This error happens if you call setState() on a State objectfor a widget that no longer appears in the widget tree (e.g., whoseparent widget no longer includes the widget in its build). This errorcan occur when code calls setState() from a timer or an animationcallback. The preferred solution is to cancel the timer or stoplistening to the animation in the dispose() callback. Another solutionis to check the "mounted" property of this object before callingsetState() to ensure the object is still in the tree. This error mightindicate a memory leak if setState() is being called because anotherobject is retaining a reference to this State object after it has beenremoved from the tree. To avoid memory leaks, consider breaking thereference to this object during dispose().)

个人资料页 :

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:play_big_win/constants.dart';
import 'package:play_big_win/services/firebase-auth-helper.dart';

class MyProfile extends StatefulWidget {
  @override
  _MyProfileState createState() => _MyProfileState();
}

class _MyProfileState extends State<MyProfile> {
  final firebaseUser = FirebaseAuth.instance.currentUser;
  final db = FirebaseFirestore.instance;
  String fullname = '';
  String email = '';
  @override
  void dispose() {
    SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values);
    super.dispose();
  }

  @override
  initState() {
    SystemChrome.setEnabledSystemUIOverlays([]);
    super.initState();
  }

  getData() async {
    while (mounted) {
      dynamic names = await FirebaseAuthHelper().getCurrentUserData();
      if (names != null) {
        fullname = names[0];
        email = names[1];
        setState(() {});
      } else {
        print("Nulllll");
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    getData();
    return Scaffold(
      backgroundColor: kPrimaryColor,
      body: SafeArea(
        child: ListView(
          shrinkWrap: true,
          children: [
            SizedBox(
              height: 20,
            ),
            Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Container(
                  decoration: BoxDecoration(
                    color: Colors.white,
                    borderRadius: BorderRadius.all(
                      Radius.circular(15),
                    ),
                  ),
                  width: MediaQuery.of(context).size.width - 25,
                  height: 150,
                  child: Row(
                    children: [
                      CircleAvatar(
                        radius: 60.0,
                        backgroundImage: NetworkImage(
                          'https://res.cloudinary.com/dqunmzmqo/image/upload/v1606248032/male-clipart-avatar_ewaerc.png',
                        ),
                      ),
                      Padding(
                        padding: const EdgeInsets.only(top: 45.0),
                        child: Column(
                          children: [
                            Text(
                              "Name: $fullname",
                              style: TextStyle(
                                fontSize: 14,
                              ),
                            ),
                            SizedBox(
                              height: 10,
                            ),
                            Text(
                              "Email: $email",
                              style: TextStyle(
                                fontSize: 14,
                              ),
                            ),
                            SizedBox(
                              height: 10,
                            ),
                            Text(
                              "Refer Code: Xasdsas",
                              style: TextStyle(
                                fontSize: 14,
                              ),
                            )
                          ],
                        ),
                      ),
                    ],
                  ),
                ),
                Padding(
                  padding: const EdgeInsets.only(top: 8.0),
                  child: Text(
                    'Play Big Win Big',
                    style: TextStyle(
                      fontFamily: 'Pacifico',
                      fontSize: 20.0,
                      color: Colors.white,
                    ),
                  ),
                ),
                SizedBox(
                  height: 5,
                ),
                Text(
                  'V1.0',
                  style: TextStyle(
                    fontSize: 10.0,
                    letterSpacing: 2.5,
                    color: Colors.teal.shade100,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                SizedBox(
                  height: 20.0,
                  width: 150.0,
                  child: Divider(
                    color: Colors.teal.shade100,
                  ),
                ),
                GestureDetector(
                  onTap: () {
                    // Navigator.push(

                    //     context,

                    //     MaterialPageRoute(

                    //       builder: (context) => MyprivacyPolicy(),

                    //     ));
                  },
                  child: Card(
                    color: Colors.white,
                    margin:
                        EdgeInsets.symmetric(vertical: 10.0, horizontal: 25.0),
                    child: ListTile(
                      leading: Icon(
                        Icons.group_add,
                        color: Colors.teal,
                      ),
                      title: Text(
                        'Invite Friends',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 17.0,
                          color: Colors.teal.shade900,
                        ),
                      ),
                    ),
                  ),
                ),
                GestureDetector(
                  onTap: () {
                    // Navigator.push(

                    //     context,

                    //     MaterialPageRoute(

                    //       builder: (context) => MyprivacyPolicy(),

                    //     ));
                  },
                  child: Card(
                    color: Colors.white,
                    margin:
                        EdgeInsets.symmetric(vertical: 10.0, horizontal: 25.0),
                    child: ListTile(
                      leading: Icon(
                        Icons.question_answer,
                        color: Colors.teal,
                      ),
                      title: Text(
                        "FAQ's",
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 17.0,
                          color: Colors.teal.shade900,
                        ),
                      ),
                    ),
                  ),
                ),
                GestureDetector(
                  onTap: () {
                    // Navigator.push(

                    //     context,

                    //     MaterialPageRoute(

                    //       builder: (context) => MyprivacyPolicy(),

                    //     ));
                  },
                  child: Card(
                    color: Colors.white,
                    margin:
                        EdgeInsets.symmetric(vertical: 10.0, horizontal: 25.0),
                    child: ListTile(
                      leading: Icon(
                        Icons.privacy_tip,
                        color: Colors.teal,
                      ),
                      title: Text(
                        'Privacy Policy',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 17.0,
                          color: Colors.teal.shade900,
                        ),
                      ),
                    ),
                  ),
                ),
                GestureDetector(
                  onTap: () {
                    // Navigator.push(

                    //     context,

                    //     MaterialPageRoute(

                    //       builder: (context) => TermsandCondtions(),

                    //     ));
                  },
                  child: Card(
                    color: Colors.white,
                    margin:
                        EdgeInsets.symmetric(vertical: 10.0, horizontal: 25.0),
                    child: ListTile(
                      leading: Icon(
                        Icons.auto_fix_normal,
                        color: Colors.teal,
                      ),
                      title: Text(
                        'Terms & Conditions',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 17.0,
                          color: Colors.teal.shade900,
                        ),
                      ),
                    ),
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

通知页面:

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

import '../../constants.dart';

class MyNotification extends StatefulWidget {
  @override
  _MyNotificationState createState() => _MyNotificationState();
}

class _MyNotificationState extends State<MyNotification> {
  @override
  void dispose() {
    SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values);
    super.dispose();
  }

  @override
  initState() {
    SystemChrome.setEnabledSystemUIOverlays([]);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        backgroundColor: kPrimaryColor,
        title: Text(
          "Notifications",
        ),
      ),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(15.0),
          child: Container(
            decoration: BoxDecoration(
              color: Colors.deepPurple,
              borderRadius: BorderRadius.all(
                Radius.circular(
                  20,
                ),
              ),
            ),
            height: 300,
            width: MediaQuery.of(context).size.width,
            child: Center(
              child: Padding(
                padding: const EdgeInsets.all(12.0),
                child: Text(
                  "Today Is Your sadsadasdas das das dsa sa dsa dsad asd as das asd sad asd asds das sa dsa",
                  style: TextStyle(
                    color: Colors.white,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

我的验证码:

Future getCurrentUserData() async {
    try {
      DocumentSnapshot ds = await users.doc(firebaseUser.uid).get();
      String fullname = ds.get('full_name');
      String email = ds.get('email');
      return [fullname, email];
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

我在个人资料页面中调用的这段代码:

 getData() async {
    while (mounted) {
      dynamic names = await FirebaseAuthHelper().getCurrentUserData();
      if (names != null) {
        fullname = names[0];
        email = names[1];
        setState(() {});
      } else {
        print("Null");
      }
    }
  }

Answer 1

您在 async 函数中使用 setState，等待后，您的小部件可能不再安装。做 setState 会在那个时候给你一个异常(exception)。使用以下代码或将其放在任何其他地方

if (this.mounted) {
setState(() {
 });
 }

或更明确的方法覆盖 setState

@override
  void setState(fn) {
    if(mounted) {
      super.setState(fn);
    }
  }