我正在尝试创建一个简单的第一个应用程序,以一组TabBar选项卡为中心。我希望这些选项卡中的一个包含一个按钮,单击该按钮后将启动一个模式,这似乎有必要将小部件推到导航堆栈中。
选项卡中的东西工作正常,但是尝试推送模式窗口小部件会导致'package:flutter/src/widgets/navigator.dart': Failed assertion: line 2330 pos 12: '!_debugLocked': is not true.
,该代码用于“防止再次进入呼叫推送,弹出和好友”。
关于这种方法的任何事情看起来显然是错误的吗?我将文本小部件替换为实际的模式,以简化对错误源的跟踪。
class SessionsView extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Timer(),
]);
}
}
class Timer extends StatefulWidget {
@override
State<Timer> createState() => _Timer();
}
class _Timer extends State<Timer> {
Duration timerDuration;
@override
void initState() {
super.initState();
timerDuration = Duration(seconds: 10);
}
@override
Widget build(BuildContext context) {
return Row(
children: <Widget>[
TimerIconButton(),
],
);
}
}
class TimerIconButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
return IconButton(
onPressed: launchTestModal(context),
alignment: Alignment.centerLeft,
icon: Icon(Icons.timelapse),
);
}
}
launchTestModal(BuildContext context) {
Navigator.push(
context,
MaterialPageRoute<Null>(
builder: (BuildContext context) {
return Text('something');
},
fullscreenDialog: true,
));
}
答案 0 :(得分:0)
您可以在下面复制粘贴运行完整代码
您需要使用WidgetsBinding.instance.addPostFrameCallback
代码段
launchTestModal(BuildContext context) {
WidgetsBinding.instance.addPostFrameCallback((_) {
Navigator.push(
context,
MaterialPageRoute<Null>(
builder: (BuildContext context) {
return Text('something');
},
fullscreenDialog: true,
));
});
}
工作演示
完整代码
import 'package:flutter/material.dart';
class SessionsView extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
body: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Timer(),
]),
);
}
}
class Timer extends StatefulWidget {
@override
State<Timer> createState() => _Timer();
}
class _Timer extends State<Timer> {
Duration timerDuration;
@override
void initState() {
super.initState();
timerDuration = Duration(seconds: 10);
}
@override
Widget build(BuildContext context) {
return Row(
children: <Widget>[
TimerIconButton(),
],
);
}
}
class TimerIconButton extends StatelessWidget {
@override
Widget build(BuildContext context) {
return IconButton(
onPressed: launchTestModal(context),
alignment: Alignment.centerLeft,
icon: Icon(Icons.timelapse),
);
}
}
launchTestModal(BuildContext context) {
WidgetsBinding.instance.addPostFrameCallback((_) {
Navigator.push(
context,
MaterialPageRoute<Null>(
builder: (BuildContext context) {
return Text('something');
},
fullscreenDialog: true,
));
});
}
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: SessionsView(),
);
}
}