how to open camera on flutter - flutter

Question

can anyone help me to open camera on flutter app but i'm getting I/flutter (12909): NoSuchMethodError: The getter 'name' was called on null. I/flutter (12909): Receiver: null I/flutter (12909): Tried calling: name
i dont know why
here is my code
`import 'dart:async';
import 'dart:io';
import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
Future<void> main() async {
// Ensure that plugin services are initialized so that `availableCameras()`
// can be called before `runApp()`
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.
final firstCamera = cameras.first;
runApp(
MaterialApp(
theme: ThemeData.dark(),
home: TakePictureScreen(
// Pass the appropriate camera to the TakePictureScreen widget.
camera: firstCamera,
),
),
);
}
// A screen that allows users to take a picture using a given camera.
class TakePictureScreen extends StatefulWidget {
final CameraDescription camera;
const TakePictureScreen({
Key key,
#required this.camera,
}) : super(key: key);
#override
TakePictureScreenState createState() => TakePictureScreenState();
}
class TakePictureScreenState extends State<TakePictureScreen> {
CameraController _controller;
Future<void> _initializeControllerFuture;
#override
void initState() {
super.initState();
// To display the current output from the Camera,
// create a CameraController.
_controller = CameraController(
// Get a specific camera from the list of available cameras.
widget.camera,
// Define the resolution to use.
ResolutionPreset.medium,
);
// Next, initialize the controller. This returns a Future.
_initializeControllerFuture = _controller.initialize();
}
#override
void dispose() {
// Dispose of the controller when the widget is disposed.
_controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('Take a picture')),
// Wait until the controller is initialized before displaying the
// camera preview. Use a FutureBuilder to display a loading spinner
// until the controller has finished initializing.
body: FutureBuilder<void>(
future: _initializeControllerFuture,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
// If the Future is complete, display the preview.
return CameraPreview(_controller);
} else {
// Otherwise, display a loading indicator.
return Center(child: CircularProgressIndicator());
}
},
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.camera_alt),
// Provide an onPressed callback.
onPressed: () async {
// Take the Picture in a try / catch block. If anything goes wrong,
// catch the error.
try {
// Ensure that the camera is initialized.
await _initializeControllerFuture;
// Attempt to take a picture and get the file `image`
// where it was saved.
final image = await _controller.takePicture();
// If the picture was taken, display it on a new screen.
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => DisplayPictureScreen(
// Pass the automatically generated path to
// the DisplayPictureScreen widget.
imagePath: image?.path,
),
),
);
} catch (e) {
// If an error occurs, log the error to the console.
print(e);
}
},
),
);
}
}
// A widget that displays the picture taken by the user.
class DisplayPictureScreen extends StatelessWidget {
final String imagePath;
const DisplayPictureScreen({Key key, this.imagePath}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('Display the Picture')),
// The image is stored as a file on the device. Use the `Image.file`
// constructor with the given path to display the image.
body: Image.file(File(imagePath)),
);
}
}
From https://flutter.dev/docs/cookbook/plugins/picture-using-camera#3-create-and-initialize-the-cameracontroller

Answer 1

I assume you have already added the camera package from pub site in your pubspec.yaml file and sync / get the dependencies.
In my case, I tested on my Android Emulator as well as Android Physical device too. The problem which I faced was from the app/build.gradle file where the camera plugin required the minSdkVersion 21 but By default it was minSdkVersion 16
Upgrading to the SdkVersion solves the first issue. Make sure to upgrade the minSdkVersion from 16 to 21 and should look like minSdkVersion 21
NOTE: Allow the required Runtime Permission required by the camera plugin.
I hope this solution will help you to solve your issue.