如果用户拒绝摄像头访问，则无法显示警报

Question

如果用户拒绝相机访问，我将显示一个带有取消和设置按钮的警报以显示它。但代码不起作用。

@IBAction func ProfileImageButton(_ sender: UIButton) {
        print("profile image Button is pressed")
        let imagePickerController = UIImagePickerController()
        imagePickerController.delegate = self
        profileimgbool = true
        let actionSheet = UIAlertController(title: "Photo Source", message: "choose a Source", preferredStyle: .actionSheet)

        actionSheet.addAction(UIAlertAction(title: "Camera", style: .default, handler: {(action:UIAlertAction) in imagePickerController.sourceType = .camera
            self.present(imagePickerController, animated: true, completion: nil)

        }))

        actionSheet.addAction(UIAlertAction(title: "Photo Library", style: .default, handler: {(action:UIAlertAction) in imagePickerController.sourceType = .photoLibrary
            self.present(imagePickerController, animated: true, completion: nil)}))

        actionSheet.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))



        self.present(actionSheet, animated: true, completion: nil)

    }

 func checkCameraPermission()  {
        let cameraMediaType = AVMediaType.video
        AVCaptureDevice.requestAccess(for: cameraMediaType) { granted in
            if granted {
                //Do operation
                print("Granted access for camera")
               // self.setCamera()
            } else {
                self.noCameraFound()
                print("Denied access for camera ")
            }
        }
    }
    func noCameraFound(){
        let alert = UIAlertController(title: "CallDoc", message: "Please allow camera access in phone settings", preferredStyle: UIAlertControllerStyle.alert)
        alert.addAction(UIAlertAction(title: "Back", style: UIAlertActionStyle.cancel, handler: {(action:UIAlertAction) in


        }));

        alert.addAction(UIAlertAction(title: "Open setting", style: UIAlertActionStyle.default, handler: {(action:UIAlertAction) in
            UIApplication.shared.open(NSURL(string:UIApplicationOpenSettingsURLString)! as URL, options: [:], completionHandler: nil)

        }));
        self.present(alert, animated: true, completion: nil)
    }

在我上面的代码中，我的方法是checkCameraPermission调用它来显示警报。我需要在用户单击相机时显示，如果用户拒绝则显示黑屏而不是相机。我需要显示弹出的警报。

我可以在哪里调用此checkCameraPermission方法来显示我的弹出窗口？

任何想法 ？

Answer 1

出于参考目的，我从本教程中获取了答案。

\n\n

步骤1

\n\n

在您的项目中添加 avfoundation 框架

\n\n

import AVFoundation\n

\n\n

第2步

\n\n

不要忘记在 Info.plist 中设置相机使用说明

\n\n

当您请求使用 device\xe2\x80\x99s 相机的权限时，默认的 iOS 系统对话框中会出现一条短消息。Privacy - Camera Usage Description您可以通过将密钥添加到文件来自定义此消息Info.plist。

\n\n

步骤3

\n\n

在您的图像配置文件更改按钮操作上验证权限等。

\n\n

@IBAction func ProfileImageButton(_ sender: UIButton) {\n let cameraAuthorizationStatus = AVCaptureDevice.authorizationStatus(for: .video)\n  switch cameraAuthorizationStatus {\ncase .notDetermined: requestCameraPermission()\ncase .authorized: presentCamera()\ncase .restricted, .denied: alertCameraAccessNeeded()\n}\n}\n

\n\n

基于上述操作，条件将满足，

\n\n

\n

如果用户从未响应过访问其相机的请求，则需要通过 iOS 系统警报提示请求权限：

\n

\n\n

 func requestCameraPermission() {\nAVCaptureDevice.requestAccess(for: .video, completionHandler: {accessGranted in\n    guard accessGranted == true else { return }\n    self.presentCamera()\n})\n}\n

\n\n

之后相机访问将继续

\n\n

 func presentCamera() {\nlet photoPicker = UIImagePickerController()\nphotoPicker.sourceType = .camera\nphotoPicker.delegate = self as? UIImagePickerControllerDelegate & UINavigationControllerDelegate\n\nself.present(photoPicker, animated: true, completion: nil)\n}\n

\n\n

\n

要使用相机捕获的图像，您需要设置视图控制器以遵守并实现几个委托协议：

\n

\n\n

 class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {\n  // ...\n }\n\n func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {\nlet photo = info[UIImagePickerControllerOriginalImage] as! UIImage\n// do something with the photo... set to UIImageView, save it, etc.\n\ndismiss(animated: true, completion: nil)\n}\n

\n\n

如果相机访问被拒绝或限制，您可以提醒用户并将他们引导至“设置”应用程序以进行适当的权限调整：

\n\n

func alertCameraAccessNeeded() {\nlet settingsAppURL = URL(string: UIApplicationOpenSettingsURLString)!\n\nlet alert = UIAlertController(\n    title: "Need Camera Access",\n    message: "Camera access is required to make full use of this app.",\n    preferredStyle: UIAlertControllerStyle.alert\n)\n\nalert.addAction(UIAlertAction(title: "Cancel", style: .default, handler: nil))\nalert.addAction(UIAlertAction(title: "Allow Camera", style: .cancel, handler: { (alert) -> Void in\n    UIApplication.shared.open(settingsAppURL, options: [:], completionHandler: nil)\n}))\n\npresent(alert, animated: true, completion: nil)\n}\n

\n