flutter - iphone -相机翻转图像

dependencies:
  camera: ^0.10.0

import 'package:camera/camera.dart';

List<CameraDescription> cameras;

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  cameras = await availableCameras();
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: CameraScreen(),
    );
  }
}

class CameraScreen extends StatefulWidget {
  @override
  _CameraScreenState createState() => _CameraScreenState();
}

class _CameraScreenState extends State<CameraScreen> {
  CameraController _controller;

  @override
  void initState() {
    super.initState();
    _controller = CameraController(cameras[0], ResolutionPreset.medium);
    _controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    });
  }

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

  @override
  Widget build(BuildContext context) {
    if (!_controller.value.isInitialized) {
      return Container();
    }
    return AspectRatio(
      aspectRatio: _controller.value.aspectRatio,
      child: CameraPreview(_controller),
    );
  }
}

class _CameraScreenState extends State<CameraScreen> {
  CameraController _controller;
  bool _isFrontCamera = false;

  @override
  void initState() {
    super.initState();
    _controller = CameraController(cameras[0], ResolutionPreset.medium);
    _controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    });
  }

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

  void _toggleCamera() async {
    final CameraDescription newCamera = _isFrontCamera
        ? cameras.firstWhere((camera) => camera.lensDirection == CameraLensDirection.back)
        : cameras.firstWhere((camera) => camera.lensDirection == CameraLensDirection.front);
    if (_controller != null) {
      await _controller.dispose();
    }
    _controller = CameraController(newCamera, ResolutionPreset.medium);
    _controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {
        _isFrontCamera = !_isFrontCamera;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    if (!_controller.value.isInitialized) {
      return Container();
    }
    return Column(
      children: [
        Expanded(
          child: AspectRatio(
            aspectRatio: _controller.value.aspectRatio,
            child: CameraPreview(_controller),
          ),
        ),
        RaisedButton(
          onPressed: _toggleCamera,
          child: Text(_isFrontCamera ? '切换后置摄像头' : '切换前置摄像头'),
        ),
      ],
    );
  }
}