Flutter中的相机插件中的自拍相机崩溃

如何解决Flutter中的相机插件中的自拍相机崩溃

每当我尝试从项目中的let user_data = JSON.parse(sessionStorage.getItem('data')) 插件打开前置摄像头时，应用在Pixel 3XL上崩溃，但是该应用在后置摄像头上运行正常。

插件版本：camera

我的相机课。

camera: ^0.5.8+1

Flutter Doctor输出

class CameraState extends State<Camera> with WidgetsBindingObserver {
  CameraController controller;
  List<CameraDescription> cameras;

  @override initState() {
    super.initState();
    getCameras();
  }

  void getCameras() async {
    cameras = await availableCameras();
    cameras.forEach((camera) {
      if (camera.lensDirection == CameraLensDirection.front) {
        onNewCameraSelected(camera);
      }
    });
  }

  /// Returns a suitable camera icon for [direction].
  IconData getCameraLensIcon(CameraLensDirection direction) {
    switch (direction) {
      case CameraLensDirection.back:
        return Icons.camera_rear;
      case CameraLensDirection.front:
        return Icons.camera_front;
      case CameraLensDirection.external:
        return Icons.camera;
    }
    throw ArgumentError('Unknown lens direction');
  }

  /// Display the preview from the camera (or a message if the preview is not available).
  Widget _cameraPreviewWidget() {
    if (controller == null || !controller.value.isInitialized) {
      return new Center(
        child: new Text(
          allTranslations.text('camera_no'),style: TextStyle(
              color: Colors.white,fontWeight: FontWeight.w600,fontFamily: fontMontserrat,fontStyle: FontStyle.normal,fontSize: 24.0),),);
    } else {
      final size = MediaQuery.of(context).size;
      final deviceRatio = size.width / size.height;
      return Transform.scale(
        scale: controller.value.aspectRatio / deviceRatio,child: Center(
          child: AspectRatio(
            aspectRatio: controller.value.aspectRatio,child: CameraPreview(controller),);
    }
  }

  String timestamp() => DateTime.now().millisecondsSinceEpoch.toString();

  void onNewCameraSelected(CameraDescription cameraDescription) async {
    if (controller != null) {
      await controller.dispose();
    }
    controller = CameraController(cameraDescription,ResolutionPreset.medium,enableAudio: false);

    controller.addListener(() {
      if (mounted) setState(() {});
    });

    try {
      ///
      /// APP CRASHES HERE.
      /// 
      await controller.initialize();
    } on CameraException catch (e) {
        print(e);
    }

    if (mounted) {
      setState(() {});
    }
  }

  void onTakePictureButtonPressed() {
    takePicture().then((String filePath) {
      if (filePath != null) {
       // Navigate to other screen.
      }
    });
  }

  Future<String> takePicture() async {
    if (!controller.value.isInitialized) {
      return null;
    }
    final Directory extDir = await getApplicationDocumentsDirectory();
    final String dirPath = '${extDir.path}/Pictures/flutter_test';
    await Directory(dirPath).create(recursive: true);
    final String filePath = '$dirPath/${timestamp()}.jpg';

    if (controller.value.isTakingPicture) {
      // A capture is already pending,do nothing.
      return null;
    }

    try {
      await controller.takePicture(filePath);
    } on CameraException catch (e) {
      return null;
    }
    return filePath;
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
        Positioned(
          left: 0,top: 0,right: 0,bottom: 0,child: _cameraPreviewWidget(),Scaffold(
          body: new Container(
            color: Colors.transparent,child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,children: <Widget>[
                new Text(allTranslations.text('licensescan_back'),textAlign: TextAlign.center,style: const TextStyle(
                        color:  Colors.white,fontWeight: FontWeight.w400,fontFamily: fontSourceSansPro,fontStyle:  FontStyle.normal,fontSize: 18.0
                    )
                ),Container(height: 10),Padding(
                  padding: new EdgeInsets.only(left: 40,right: 40),child: new Text(allTranslations.text('licensescan_positionback'),style: const TextStyle(
                          color:  Colors.white,fontSize: 13.0
                      )
                  ),Expanded(child: new Container()),new FlatButton(
                    onPressed: onTakePictureButtonPressed,child: new Container(
                      width: 54,height: 54,decoration: BoxDecoration(
                          borderRadius: BorderRadius.circular(27),border: Border.all(
                              color: Colors.white
                          ),color: Colors.transparent
                      ),child: Center(
                        child: new Container(
                          width: 45,height: 45,decoration: BoxDecoration(
                              borderRadius: BorderRadius.circular(22.5),color: Colors.white
                          ),)
                ),new Container(height: 58)
              ],)
      ],);
  }
}

崩溃日志

Doctor summary (to see all details,run flutter doctor -v):
[✓] Flutter (Channel stable,v1.17.1,on Mac OS X 10.15.1 19B88,locale en-GB)
 
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[✓] Xcode - develop for iOS and macOS (Xcode 11.2.1)
[✓] Android Studio (version 4.0)
[✓] VS Code (version 1.48.0)
[✓] Connected device (1 available)

• No issues found!

对此thread也尝试了几乎所有解决方案，但没有运气。

解决方法

我的相机拍照功能崩溃了。

"java.lang.NullPointerException: Attempt to invoke virtual method 'int io.flutter.embedding.engine.systemchannels.PlatformChannel$DeviceOrientation.ordinal()' 在空对象引用 E/AndroidRuntime(18591) 上： io.flutter.plugins.camera.DeviceOrientationManager.getMediaOrientation(DeviceOrientationManager.java:58)"

对我来说帮助添加 在 initialize() 之后等待 controller.lockCaptureOrientation()。 试试这个，也许对你有帮助

   try {
          ///
          /// APP CRASHES HERE.
          /// 
          await controller.initialize();
          await controller.lockCaptureOrientation();

        }