Develop Reference

flutter Problem in vs code (Unable to Load asset)

I'm having a problem in flutter on vs code
I imported the audioplayers
here's my pubspec.yaml
here's my homepage where I call the audio players
import 'package:flutter/material.dart';
import 'package:audioplayers/audioplayers.dart';
class HomeScreen extends StatefulWidget {
const HomeScreen({super.key});
#override
State<HomeScreen> createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.brown,
title: Text('anghami'),
),
body: Container(
color: Colors.brown[200],
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
Card(
child: ListTile(
title: Text(
"benab",
style: TextStyle(color: Colors.red),
),
//tileColor: Colors.red,
leading: Icon(Icons.music_note),
iconColor: Colors.red,
onTap: () async {
final player = AudioPlayer();
await player
.setSource(AssetSource('assets/music/music1.mp3'));
},
),
),
],
),
),
),
);
}
}
whenever i try to play the music from the phone I get this error
P.S: the vs code has no problem in loading images or using other type of assets .
i've tried using Audiocache it doesn't work especially they deleted it in the last version ^1.1.1 ,
[enter image description here][https://i.stack.imgur.com/u9kKR.png]

It seems you trying to load an asset in /assets/assets/music/ folder.
My guess is that you want to load an asset in /assets/music/ folder and it's a simple mistake.
To fix that:
// Replace the relative path of your asset below:
// assets/music/music1.mp3 -> music/music1.mp3
await player.setSource(AssetSource('music/music1.mp3'));

Just remove assets from your audio source like this:
await player.setSource(AssetSource('music/music1.mp3'));

Firstly, create a assets directory on the root of your project , then create music folder.
Try to play with
await player.setSource(AssetSource('music/music1.mp3'));

Hello guys the solutions here are useful , so the main problem that I had was in the path so after correction it loaded the asset in a normal way,
but instead of just loading the asset you want it to play obviously and that's guaranteed by using :
**final player = AudioPlayer();**
**await player.play(AssetSource('music/music1.mp3'));**

Flutter - How to handle Non-Nullable Instance of widget properties

I am new to flutter and currently trying to simple animation on my component, but i keep getting a " Non-Nullable Instance " error, i checked out other video tutorials but theirs worked perfectly while mine keeps throwing errors.
Here's my code.
class HomeScreen extends StatefulWidget {
#override
State<HomeScreen> createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> with TickerProviderStateMixin {
Animation<Offset> sbarAnimation;
AnimationController sbarAnimationController;
#override
void initState() {
super.initState();
sbarAnimationController = AnimationController(
vsync: this,
duration: Duration(milliseconds: 250),
);
sbarAnimation = Tween<Offset>(
begin: Offset(-1, 0),
end: Offset(0, 0),
).animate(
CurvedAnimation(
parent: sbarAnimationController,
curve: Curves.easeInOut,
),
);
}
And then the code for the widget is below
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
color: kBackgroundColor,
child: Stack(
children: [
SafeArea(
//so the background covers the entire app..
child: Column(
children: [
HomeScreenNavBar(),
ExploreCourseList(),
],
),
),
SlideTransition(
position: sbarAnimation, // this is where i call the _animation
child: SafeArea(
child: SidebarScreen(),
bottom: false,
),
),
],
),
),
);
}
}
below is the errors i keep getting, and most of the solutions i've seen did exactly the same thing, theirs works, but mine is giving this errors.. please what am i supposed to do.

There two way to solve the issue.
Which already answered by Juan Carlos Ramón Condezo, using late keyword, where you must have to initialize it before using anywhere.
You can make the variable nullable. By using '?' After declaring the variable type.
Animation?<Offset> sbarAnimation;
AnimationController? sbarAnimationController;
So, you can check if the variable is null and initialize it when needed.

Use late keyword to initialize variables later as you are doing in your initState
late Animation<Offset> sbarAnimation;
late AnimationController sbarAnimationController;

VSCode, Flutter - red underline

Firstly, I was trying to import a project that contains a complete Webview and I was surprised that even after running flutter clean ; flutter pub get I would still get errors.
I then tried to recreate the demo app following https://flutter.dev/docs/get-started/codelab which was working fine at first yesterday. From here I saw that I get the same errors,
Here's my .dart code for the demo app :
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}
Sorry for showing the errors by a screenshot but the logs when building are way too long to share, since I think it's a common problem it shouldn't be that troublesome, let me know if you need the errors so I'll do a pastebin.
Thank you guys

It looks like you maybe getting some errors while getting the dependencies and flutter is not being downloaded correctly.
If its still happening review your dependencies and do a:
flutter clean
flutter pub upgrade
If it still happens, review the log of flutter pub get to see what error you maybe getting from the dependencies.
There is another command that could work if your case is that the dependencies are not being updated locally, not on your project, but on your flutter cache. You can use:
flutter pub cache repair

The only solution I found was to delete the Flutter SDK (just delete the folder you downloaded) and to reinstall via git just because I prefer it that way.
I also moved the SDK from C:/Users/my_user/ to C:/src.

flutter: Another exception was thrown: NoSuchMethodError: The getter '_duration' was called on null

Hello developer i am using chewie plugin for playing live streaming video its is m3u8 video link when run it ios real device it give this exception "The getter '_duration' was called on null." on ios while its work fine on android device but ios real device. i dont know how solve issue on ios real device any expert developer is here is who can help solving this issue
here is exception.
flutter: Another exception was thrown: NoSuchMethodError: The getter '_duration' was called on null.
my code
import 'package:chewie/chewie.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:video_player/video_player.dart';
class ChewieListItem extends StatefulWidget {
// This will contain the URL/asset path which we want to play
final VideoPlayerController videoPlayerController;
final bool looping;
ChewieListItem({
#required this.videoPlayerController,
this.looping,
Key key,
}) : super(key: key);
#override
_ChewieListItemState createState() => _ChewieListItemState();
}
class _ChewieListItemState extends State<ChewieListItem> {
ChewieController _chewieController;
#override
void initState() {
super.initState();
// Wrapper on top of the videoPlayerController
_chewieController = ChewieController(
videoPlayerController: widget.videoPlayerController,
aspectRatio: 16 / 9,
// Prepare the video to be played and display the first frame
autoInitialize: true,
looping: widget.looping,
deviceOrientationsAfterFullScreen:[DeviceOrientation.portraitUp] ,
// Errors can occur for example when trying to play a video
// from a non-existent URL
errorBuilder: (context, errorMessage) {
return Center(
child: Text(
errorMessage,
style: TextStyle(color: Colors.white),
),
);
},
);
}
#override
Widget build(BuildContext context) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: Chewie(
controller: _chewieController,
),
);
}
#override
void dispose() {
super.dispose();
SystemChrome.setPreferredOrientations([
DeviceOrientation.portraitUp,
]);
// IMPORTANT to dispose of all the used resources
widget.videoPlayerController.dispose();
_chewieController.dispose();
_chewieController.pause();
}
}
streaming
child: Column(
children: <Widget>[
Expanded(
child: ChewieListItem(
videoPlayerController: VideoPlayerController.network(
'https://streamer12.vdn.dstreamone.net/livinghope/livinghope/playlist.m3u8',),
),
)

Flutter: Is there a way to prevent the screen from turning off?

I want to build a 'Nightstand Clock' app, and I want the phone to display the clock as long as the app is active without turning off the screen.
Is there a way to do this in Flutter?
I found this SO answer, but using the 'screen' plugin didn't work for me.
After adding the dependency to 'pubspecc.yaml' and running flutter packages get my app doesn't run anymore and Android SDK is getting stuck at the 'resolving dependencies' stage.
Either way, is there any other way to do this in flutter except the 'screen' plugin?

From the same SO post,it mentioned that the screen plugin encountered some issues. I've checked the plugin and it seems that it was not updated since March 13, 2019. Another plugin that would give the same function you needed is wakelock plugin. It is still available currently maintained by the author. In fact, latest version 0.5.0+2 was release last March 7, 2021.
Hi, I am still maintaining it :) We recently added macOS support as
well 🚀 Also, Flutter is open source - they have first-party plugins,
however, they do say themselves that they will abandon their
first-party solutions if a better third party project exists. So why
would they want to create one for something that works perfectly fine?
– creativecreatorormaybenot Feb 8 at 16:17
I've tested the sample given in the wakelock package:
import 'package:flutter/material.dart';
import 'package:wakelock/wakelock.dart';
void main() {
runApp(WakelockExampleApp());
}
class WakelockExampleApp extends StatefulWidget {
#override
_WakelockExampleAppState createState() => _WakelockExampleAppState();
}
class _WakelockExampleAppState extends State<WakelockExampleApp> {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Wakelock example app'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
const Spacer(
flex: 3,
),
OutlinedButton(
onPressed: () {
setState(() {
Wakelock.enable();
});
},
child: const Text('enable wakelock'),
),
const Spacer(),
OutlinedButton(
onPressed: () {
setState(() {
Wakelock.disable();
});
},
child: const Text('disable wakelock'),
),
const Spacer(
flex: 2,
),
FutureBuilder(
future: Wakelock.enabled,
builder: (context, AsyncSnapshot<bool> snapshot) {
final data = snapshot.data;
if (data == null) {
return Container();
}
return Text('The wakelock is currently '
'${data ? 'enabled' : 'disabled'}.');
},
),
const Spacer(
flex: 3,
),
],
),
),
),
);
}
}
Here is the output in Android:
Output in iOS:
Also, it seems that you've resolved the previous issue in your code. It would be nice to share a minimal, complete and verifiable example for the community to understand the issue very well.