Unhandled Exception: Bad state: No element - ios

Question

My build was working fine until I added an image to the launch screen, when I started getting a PhaseScript error. I had to completely delete the ios folder, recreate it, and then make the necessary manual changes again. Now when I run the build on a simulator through android studio, I get this error once the app starts:
[VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: Bad state: No element
#0 List.first (dart:core-patch/growable_array.dart:339:5)
#1 main (package:globe_flutter/main.dart:19:25)
<asynchronous suspension>
Nothing shows up on the screen. I use a tabBar in the main.dart and a tabBarView to show the different screens. Here is the main.dart:
var firstCamera;
Future<void> main() async {
WidgetsFlutterBinding.ensureInitialized();
// Obtain a list of the available cameras on the device.
final cameras = await availableCameras();
// Get a specific camera from the list of available cameras.
firstCamera = cameras.first;
await Firebase.initializeApp();
runApp(MyApp());
}
// void main() async {
// WidgetsFlutterBinding.ensureInitialized();
// await Firebase.initializeApp();
// runApp(MyApp());
// }
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'GLOBE',
debugShowCheckedModeBanner: false,
home: const MyHome(),
routes: {
LoginScreen.id: (context) => LoginScreen(),
SignupScreen.id: (context) => SignupScreen(),
HomeScreen.id: (context) => HomeScreen()
},
);
}
}
class MyHome extends StatefulWidget {
const MyHome({Key? key}) : super(key: key);
#override
_MyHomeState createState() => _MyHomeState();
}
class _MyHomeState extends State<MyHome> with SingleTickerProviderStateMixin {
late TabController _tabController;
#override
void initState() {
super.initState();
_tabController = TabController(length: 5, vsync: this);
}
#override
void dispose() {
super.dispose();
_tabController.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: TabBarView(
children: [
HomeScreen(),
HomeScreen(),
TakePictureScreen(camera: firstCamera),
HomeScreen(),
ProfileScreen(username: "cjmofficial")
],
controller: _tabController
),
extendBody: true,
bottomNavigationBar: Container(
color: Colors.transparent,
padding: EdgeInsets.symmetric(vertical: 40, horizontal: 40),
child: ClipRRect(
clipBehavior: Clip.hardEdge,
borderRadius: BorderRadius.circular(50.0),
child: Container(
height: 55,
color: Colors.grey[200],
child: TabBar(
labelColor: Colors.teal[200],
unselectedLabelColor: Colors.blueGrey,
indicator: UnderlineTabIndicator(
borderSide: BorderSide(color: Colors.teal),
insets: EdgeInsets.fromLTRB(50, 0, 50, 40)
),
indicatorColor: Colors.teal,
tabs: [
Tab(icon: Icon(Icons.home_outlined)),
Tab(icon: Icon(Icons.explore_outlined)),
Tab(icon: Icon(Icons.camera_alt_outlined)),
Tab(icon: Icon(Icons.movie_outlined)),
Tab(icon: Icon(Icons.person_outline))
],
controller: _tabController),
),
),
),
);
}
}
and the first screen that is supposed to show in the TabBarView:
class HomeScreen extends StatefulWidget {
const HomeScreen({Key? key}) : super(key: key);
static const String id = "home_screen";
#override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
Color _likeButtonColor = Colors.black;
Widget _buildPost(String username, String imageUrl, String caption, String pfpUrl) {
return Container(
color: Colors.white,
child: Column(
children: [
GestureDetector(
onTap: (){},
child: Container(
height: 50,
color: Colors.deepOrangeAccent[100],
child: Row(
children: [
SizedBox(width: 5),
CircleAvatar(
child: ClipOval(
child: Image.network(
pfpUrl,
height: 40,
width: 40,
),
),
),
SizedBox(width: 10),
Icon(Icons.more_vert, size: 20),
SizedBox(width: 10),
Text(username, style: TextStyle(fontSize: 15))
],
),
),
),
Stack(
children: [
Image.asset("images/post_background.jpg"),
Padding(
padding: const EdgeInsets.all(20.0),
child: ClipRRect(
borderRadius: BorderRadius.circular(8.0),
child: Image.network(imageUrl, fit: BoxFit.cover)),
),
],
),
Container(
height: 100,
child: Column(
children: [
const SizedBox(height: 5),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
IconButton(
onPressed: () {
setState(() {
HapticFeedback.lightImpact();
});
},
icon: Icon(Icons.thumb_up_alt_outlined, size: 30)),
Text("l", style: TextStyle(fontSize: 30)),
IconButton(
onPressed: () {
setState(() {
HapticFeedback.lightImpact();
GallerySaver.saveImage(imageUrl);
});
},
icon: Icon(Icons.ios_share, size: 30))
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Text(caption, style: const TextStyle(fontSize: 15))
],
)
],
),
)
],
),
);
}
List<Post> listPosts = [];
fetchPosts() async {
final userRef = FirebaseFirestore.instance.collection('users');
final QuerySnapshot result = await userRef.get();
result.docs.forEach((res) async {
print(res.id);
QuerySnapshot posts = await userRef.doc(res.id).collection("posts").get();
posts.docs.forEach((res) {
listPosts.add(Post.fromJson(res.data() as Map<String, dynamic>));
});
// Other method
// listPosts = posts.docs.map((doc) => Post.fromJson(doc.data() as Map<String, dynamic>)).toList();
setState(() {});
});
setState(() {
listPosts.sort((a, b) => a.postedDate.compareTo(b.postedDate));
});
}
pfpUrl(String username) async {
// Get pfpUrl
String downloadURL = await FirebaseStorage.instance
.ref(username + "/profile_picture.png")
.getDownloadURL();
return downloadURL;
}
#override
void initState() {
fetchPosts();
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: PreferredSize(
preferredSize: Size.fromHeight(45.0),
child: AppBar(
leading:
Icon(Icons.monetization_on_outlined, color: Colors.blueGrey),
centerTitle: true,
title: Text("GLOBE", style: TextStyle(color: Colors.blueGrey)),
actions: [
Icon(Icons.search, color: Colors.blueGrey),
SizedBox(width: 10)
],
backgroundColor: Colors.tealAccent[100]),
),
body: ListView.builder(
itemCount: listPosts.length,
itemBuilder: (BuildContext context, int index) {
// We retrieve the post at index « index »
final post = listPosts[index];
// Get name from id
var parts = post.id.split('_');
var username = parts[0].trim();
// Get pfpUrl
String pfpUrlString = "https://play-lh.googleusercontent.com/IeNJWoKYx1waOhfWF6TiuSiWBLfqLb18lmZYXSgsH1fvb8v1IYiZr5aYWe0Gxu-pVZX3";
return _buildPost(username, post.postUrlString, post.caption, pfpUrlString);
}),
);
}
}
I'm new to flutter and all I can understand about this is that something cannot load. I also ran a build with verbose but it didn't give anymore information. If someone can help me understand the issue, that would be great.

Answer 1

Ios simulators do not have cameras so on line 19, when firstCamera = cameras.first is called, there is no first camera.