我添加了setState()方法,得到了一个错误。终端错误(我使用flutter run -d chrome --web-hostname localhost --web-port 7357命令,所以它在终端中):
══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following assertion was thrown building StreamBuilder<List<BusinessModel>>(
使用flutter 2.x和Get package版本^4.1.2。
我有一个像这样的小部件:
class InitializationScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
body: FutureBuilder(
future:
// this is just for testing purposes
Future.delayed(const Du
我正在尝试实现提供者,它看起来很好,但是我得到了这样的信息:
这个_DefaultInheritedProviderScope小部件不能标记为需要构建,因为框架已经在构建小部件的过程中了。只有当小部件的祖先之一正在构建时,才能将其标记为需要在构建阶段构建。允许此异常是因为框架在子程序之前构建父部件,这意味着将始终生成脏子代。否则,框架可能不会在此构建阶段访问此小部件。调用setState()或markNeedsBuild()的小部件是:_DefaultInheritedProviderScope值:侦听小部件值的'UserProfile‘实例,这个小部件在发出错误调用时正在构建: Fu
您好,我正面临一个问题,我的flutter应用程序使用提供商和消费者。 当我在调试器中遇到这个问题时,一切都很正常: ════════ Exception caught by foundation library ════════════════════════════════
The following assertion was thrown while dispatching notifications for CatergoryProvider:
setState() or markNeedsBuild() called during build.
This _InheritedP
这是我的main.dart
class MyApp extends StatelessWidget {
var login = new Login("xxxxxxx", "xxxxxxxxx");
final scaffoldKey = new GlobalKey<ScaffoldState>();
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Fetch Data Example',
theme: Theme
启动后,我正在尝试处理我的应用程序的屏幕。
预期的路线是:
boot -> check if is logged in -> if yes -> navigator.push() to MainWindow.
boot -> check if is logged in -> no snapshot data -> navigator.push() to LoadingScreen.
boot -> check if is logged in -> if no -> navigator.push() to LoginScreen.
函数在Ma
我试图根据FutureBuilder收到的结果来设置状态,看起来这是不可能的,因为FutureBuild还在构建,有什么想法吗?
错误:
The following assertion was thrown building FutureBuilder<String>(dirty, state: _FutureBuilderState<String>#db9f1):
setState() or markNeedsBuild() called during build.
This StatefulBuilder widget cannot be marked as ne
我已经编写了一些简化的代码,我希望firestore数据的条件能够更新父小部件。
我得到的错误是:在构建过程中调用了setState()或markNeedsBuild()。
如何从StreamBuilder内部更新myVar的状态?更新myVar后,将不会访问StreamBuilder,而只会访问等待的文本...应显示。
编辑:我将myVar更新为Firestore的文档ID。为了清楚起见,我希望能够从StreamBuilder内部更新StreamBuilder的文档。换句话说,正如问题所说,从子StreamBuilder更新有状态小部件。
class MyWidget extends Sta
我试图通过使用提供程序更新流中的当前跟踪。但是我得到了这个错误,下面会提到
我想做的是,每次播放一首新歌时,我都想得到歌曲数据,并将其与我可以显示这首歌现在正在播放的歌曲列表进行比较。不管名单在树上什么地方。
/这是提供者正在调用的类。
import 'package:flutter/foundation.dart';
class MyCurrentTrack with ChangeNotifier{
String _currentTrack = " ";
String get currentTrack => _currentTrack;
se
基础库═捕获到═异常 在调度AuthService的通知时引发了以下断言:生成期间调用的setState()或markNeedsBuild()。 我收到以下错误: This _InheritedProviderScope<AuthService> widget cannot be marked as needing to build because the framework is already in the process of building widgets. A widget can be marked as needing to be built during th
在颤振中,我使用FutureBuilder显示来自API的数据。当出现错误时,我想弹出一个错误对话框。
但是,当我调用showDialog()时,它会引发错误。
setState() or markNeedsBuild() called during build.
这是我的密码
return FutureBuilder(
future: xxx,
builder: (context, snapshot) {
if (snapshot.hasData) {
//DO SOMETHING
} else if (s
我的目标是在单击ExpansionTile时加载一次Future并存储值,这样当Tile关闭然后重新打开时,Future就不会再次加载。
我当前代码的问题是这个错误:
I/flutter (30528): The following assertion was thrown building FutureBuilder<Trim>(dirty, state:
I/flutter (30528): _FutureBuilderState<Trim>#90a6d):
I/flutter (30528): setState() or markNeedsBuild() call
我正在尝试使用三元语句在flutter StreamBuilder小部件中有条件地重定向身份验证表单。 当重定向条件返回true时,我会看到一个红屏和以下日志: I/flutter ( 3787): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 3787): The following assertion was thrown building StreamBuilder<Map<dynamic, dy