【发布时间】：2022-01-23 03:35:48
【问题描述】：
我在尝试启动 Flutter WebView 时遇到异常。我得到的例外是：
if (errorCode is String && (errorMessage == null || errorMessage is String) && !buffer.hasRemaining)
throw PlatformException(code: errorCode, message: errorMessage as String?, details: errorDetails, stacktrace: errorStacktrace);
else
throw const FormatException('Invalid envelope');
我尝试通过单击底部导航栏中的按钮来启动 Webview。我用一个显示 web 视图的小部件创建了一个不同的类。我试图调用包含 webview 的类。
我将附上下面的整个代码以便更好地理解。谢谢。
完整代码：
class dashboard extends StatefulWidget {
@override
_dashboardState createState() => _dashboardState();
}
class Google extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Google',
home: Scaffold(
appBar: AppBar(
title: const Text(
'Google',
),
),
body: const WebView(
initialUrl: "https://codeseasy.com",
javascriptMode: JavascriptMode.unrestricted,
),
),
);
}
}
// ignore: camel_case_types
class _dashboardState extends State<dashboard> {
int currentIndex = 1;
changeIndex(index) {
setState(() {
currentIndex = index;
});
}
void onTabTapped(int index) {
if (index == 2) {
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => HomePage(),
),
);
}
if (index == 0) {
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => Google(),
),
);
}
if (index == 1) {
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => Notifications(),
),
);
}
}
final List<Widget> _children = [
HomePage(),
Notifications(),
forgotPassword(),
];
@override
Widget build(BuildContext context) {
final authService = Provider.of<AuthService>(context);
return Scaffold(
body: SingleChildScrollView(
child: Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(top: 80.0, right: 250),
child: Center(
child: Container(
width: 200.0,
height: 20.0,
decoration:
BoxDecoration(borderRadius: BorderRadius.circular(15.0)),
child: (const Text(
'Hello',
textAlign: TextAlign.center,
style: TextStyle(
fontWeight: FontWeight.bold, color: Colors.black),
)),
),
),
),
Padding(
padding: const EdgeInsets.only(left: 300.0, top: 1.0),
child: IconButton(
icon: const Icon(Icons.account_circle, size: 30.0),
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => HomePage(),
),
);
},
),
),
Padding(
padding: const EdgeInsets.only(left: 300.0, top: 5.0),
child: IconButton(
icon: const Icon(
Icons.notifications,
size: 25.0,
),
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => Notifications(),
),
);
},
),
),
Padding(
padding: const EdgeInsets.only(top: 0.0),
child: Center(
child: Container(
width: 390,
height: 450,
decoration: BoxDecoration(
color: Colors.green.shade100,
borderRadius: BorderRadius.circular(10.0)),
),
),
),
],
),
),
floatingActionButton: FloatingActionButton(onPressed: () async {
await authService.signOut();
}),
// : _children[_currentIndex],
bottomNavigationBar: BottomNavigationBar(
// currentIndex: onTabTapped,
type: BottomNavigationBarType.fixed,
backgroundColor: Colors.green[100],
onTap: onTabTapped,
items: const [
BottomNavigationBarItem(
icon: Icon(Icons.book_online),
label: 'Google',
),
BottomNavigationBarItem(
icon: Icon(Icons.read_more),
label: 'Notifications',
),
BottomNavigationBarItem(
icon: Icon(Icons.account_circle),
label: 'Profile',
),
],
),
);
}
}
异常截图：
提前谢谢你。
【问题讨论】：
-
您是否尝试过使用 Navigator.of(context).pushReplacement ？如果没有尝试使用 pushReplacement 而不是 push 导航
-
是的，使用 Navigator.of(context).pushReplacement 有效，但是当我使用 .pushReplacement 时我无法向后导航。有什么方法可以从 WebView 导航回来？
标签： flutter dart exception webview