iOS 相机权限不会出现在某些设备的设置下

Question

我在尝试使用相机时遇到了一些问题。问题是某些设备在设置下向我显示了相机条目，而另一些则没有。在那些没有出现相机开关的设备上，我无法使用相机，因为它没有权限，而且它也没有出现在设置下以启用它们。

这是它在工作设备上的外观：

这就是它在不工作的设备中的样子。

当我截取这些屏幕截图时，应用程序应该已经请求权限，但它没有。

我还验证了这些设备没有启用限制。

有什么想法吗？

更新 1：添加代码

这是我用来显示相机的代码（它在自定义视图下，而不是本机相机视图控制器）

self.captureSession = [[AVCaptureSession alloc] init];
AVCaptureDevice *videoCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoCaptureDevice error:&error];
if(videoInput)
{
    [self.captureSession addInput:videoInput];
}
else
{
    NSLog(@"Error: %@", error);
}

AVCaptureMetadataOutput *metadataOutput = [[AVCaptureMetadataOutput alloc] init];
[self.captureSession addOutput:metadataOutput];
[metadataOutput setMetadataObjectsDelegate:self
                                     queue:dispatch_get_main_queue()];
[metadataOutput setMetadataObjectTypes:@[AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeQRCode]];

AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession];
previewLayer.frame = self.view.layer.bounds;
UIView * previewView = [[UIView alloc] initWithFrame:self.view.frame];
[previewView.layer addSublayer:previewLayer];
[self.view addSubview:previewView];
[self.view sendSubviewToBack:previewView];

[self.captureSession startRunning];

Answer 1

您需要在打开会话之前请求许可。使用

[AVCaptureDevice requestAccessForMediaType:completionHandler:]

Answer 2

第 1 步：使用以下键（不带引号）在 info.plist 上提供适当的相机消息访问消息

"Privacy - Camera Usage Description"

第 2 步：对于 Objective-C/SWIFT，您需要申请相机访问权限

目标-C

[AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted)
        {
            if (granted == true)
            {
                //[self presentViewController           : picker animated:YES completion:NULL];
               //Do your stuff

            }
            else
            {
                UIAlertView *cameraAlert = [[UIAlertView alloc]initWithTitle:STR_APPLICATION_TITLE
                                                                     message:STR_ALERT_CAMERA_DENIED_MESSAGE
                                                                    delegate:self
                                                           cancelButtonTitle:@"OK"
                                                           otherButtonTitles:nil,nil];
                [cameraAlert show];

                NSLog(@"denied");
            }

        }];

斯威夫特

AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { (videoGranted: Bool) -> Void in
        if (videoGranted) {
             //Do Your stuff here

        } else {
            // Rejected Camera
        }
    })

Answer 3

在将相机类型更改为广角之前，我遇到了同样的问题：

   let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .back)

Answer 4

我需要相机给用户ARKit。每次显示带有sceneView的vc时，我都会在viewWillAppear中运行checkCameraPermission()。如果用户不允许访问，则会显示带有设置按钮的警报。一旦他们按下该按钮，他们将被带到Settings，并且带有切换开关的相机图标将始终存在。

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    checkCameraPermission()
}

func checkCameraPermission() {

    let authorizationStatus = AVCaptureDevice.authorizationStatus(for: AVMediaType.video)
    switch authorizationStatus {

    case .notDetermined:
        AVCaptureDevice.requestAccess(for: AVMediaType.video) { [weak self](granted) in
            if granted {
                print("access granted")
                DispatchQueue.main.async { [weak self] in
                    self?.startSceneViewSession()
                }

            } else {
                print("access denied")
                DispatchQueue.main.async { [weak self] in
                    self?.alertUserCameraPermissionMustBeEnabled()
                }
            }
        }

    case .authorized:
        print("Access authorized")
        startSceneViewSession()

    case .denied, .restricted:
        print("restricted")
        alertUserCameraPermissionMustBeEnabled()

    @unknown default:
        fatalError()
    }
}

func alertUserCameraPermissionMustBeEnabled() {

    let message = "Camera access is necessary to use Augemented Reality for this app.\n\nPlease go to Settings to allow access to the Camera.\n Please switch the button to the green color."

    let alert = UIAlertController (title: "Camera Access Required", message: message, preferredStyle: .alert)

    let settingsAction = UIAlertAction(title: "Settings", style: .default, handler: { (action) in

        guard let settingsUrl = URL(string: UIApplication.openSettingsURLString) else { return }

        if UIApplication.shared.canOpenURL(settingsUrl) {
            UIApplication.shared.open(settingsUrl, completionHandler: { (_) in
            })
        }
    })

    alert.addAction(settingsAction)

    present(alert, animated: true, completion: nil)
}

// this is for ARKit
func startSceneViewSession() {
    sceneView.session.run(configuration)
    sceneView.isPlaying = true
}

Answer 5

如果上述解决方案不起作用，您可以考虑在 iOS 设备上检查此设置。