How to enable camera access for Android and IOS in Flutter?

This is a Flutter code that implements a camera module. The code creates a StatefulWidget named CameraModule, which contains a single state class _CameraModuleState.

Before we step into the coding we need to get camera access from the respective devices:

For Android:

you need to modify the app's AndroidManifest.xml file. Here's an example of how to add camera permission:

<manifest ...>
  <uses-feature android:name="android.hardware.camera" />
  <uses-permission android:name="android.permission.CAMERA" />

For IOS:

Request camera access in your AppDelegate.m file by adding the following to your Info.plist file:

<key>NSCameraUsageDescription</key>
<string>This app needs access to the camera to take photos.</string>

The _CameraModuleState class has several instance variables:

• _controller is an instance of the CameraController class, which is used to control the camera.
• _cameras is a list of CameraDescription objects, which describe the available cameras on the device.
• _images is a list of strings, which store the paths to the images taken by the camera.

  late CameraController _controller;
  late List<CameraDescription> _cameras;
  List<String> _images = [];

The initState method calls the _initializeCamera method, which initializes the camera. It calls the availableCameras function to get a list of available cameras and sets the _cameras variable. Then, it creates an instance of the CameraController class, using the first camera in the list and a ResolutionPreset.medium resolution. Finally, it initializes the camera controller by calling its initialize method.

  Future<void> _initializeCamera() async {
    _cameras = await availableCameras();
    _controller = CameraController(_cameras[0], ResolutionPreset.medium);
    try {
      await _controller.initialize();
    } catch (e) {
      print(e);
    }
  }

The dispose method is called when the widget is removed from the tree. It disposes of the camera controller by calling its dispose method.

 @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

The _takePicture method takes a picture with the camera. It calls the takePicture method on the camera controller and then copies the image to a specified path. Finally, it adds the path to the _images list and calls setState to notify the framework that the state has changed and the widget tree needs to be rebuilt.

  Future<void> _takePicture() async {
    final path = 'path/to/image.jpg';
    await _controller.takePicture().then((File image) {
          image.copy(path);
        } as FutureOr Function(XFile value));
    setState(() {
      _images.add(path);
    });
  }

The build method returns a Scaffold widget that contains a camera preview and a list of taken images. The camera preview is displayed using the CameraPreview widget, which takes the camera controller as an argument. The list of images is displayed using a ListView.builder widget.

Column(
        children: [
          Expanded(
            child: FutureBuilder<void>(
              future: _initializeCamera(),
              builder: (context, snapshot) {
                if (snapshot.connectionState == ConnectionState.done) {
                  return CameraPreview(_controller);
                } else {
                  return Center(child: CircularProgressIndicator());
                }
              },
            ),
          ),
          Container(
            height: 200,
            child: ListView.builder(
              itemBuilder: (context, index) {
                return Image.file(_images[index] as File);
              },
              itemCount: _images.length,
            ),
          ),
        ],
      ),

Finally, the floatingActionButton contains a FloatingActionButton that takes a picture when pressed.

floatingActionButton: FloatingActionButton(
        onPressed: _takePicture,
        child: Icon(Icons.camera_alt),
      ),

Please find the full code below:

import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:camera/camera.dart';

class CameraModule extends StatefulWidget {
  @override
  _CameraModuleState createState() => _CameraModuleState();
}

class _CameraModuleState extends State<CameraModule> {
  late CameraController _controller;
  late List<CameraDescription> _cameras;
  List<String> _images = [];

  Future<void> _initializeCamera() async {
    _cameras = await availableCameras();
    _controller = CameraController(_cameras[0], ResolutionPreset.medium);
    try {
      await _controller.initialize();
    } catch (e) {
      print(e);
    }
  }

  @override
  void initState() {
    super.initState();
    _initializeCamera();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  Future<void> _takePicture() async {
    final path = 'path/to/image.jpg';
    await _controller.takePicture().then((File image) {
          image.copy(path);
        } as FutureOr Function(XFile value));
    setState(() {
      _images.add(path);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Camera'),
      ),
      body: Column(
        children: [
          Expanded(
            child: FutureBuilder<void>(
              future: _initializeCamera(),
              builder: (context, snapshot) {
                if (snapshot.connectionState == ConnectionState.done) {
                  return CameraPreview(_controller);
                } else {
                  return Center(child: CircularProgressIndicator());
                }
              },
            ),
          ),
          Container(
            height: 200,
            child: ListView.builder(
              itemBuilder: (context, index) {
                return Image.file(_images[index] as File);
              },
              itemCount: _images.length,
            ),
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _takePicture,
        child: Icon(Icons.camera_alt),
      ),
    );
  }
}

You can ask directly to me if you have any issues with building your app on flutter: Pradeepkumar Radhakrishnan