如何检查用户是不是允许使用相机？
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【中文标题】如何检查用户是不是允许使用相机？【英文标题】：How to check if the user gave permission to use the camera?如何检查用户是否允许使用相机？ 【发布时间】：2014-12-25 09:52:00 【问题描述】：试着写这个：
if usergavepermissiontousercamera
opencamera
else
showmycustompermissionview
找不到当前的方法来完成这个简单的任务。 注意：即使需要不同的方法也应该适用于 ios7
【问题讨论】：
你应该检查这个链接。 ***.com/questions/25803217/… 翻译成 Swift 应该不难。 AVCaptureDevice 和 AVAuthorizationStatus 都无法被 xcode 识别，可能是错误或其他问题，但是是的，这让它变得非常困难。 检查了那个答案。它用于相机胶卷，而不是它自己的相机 【参考方案1】：您可以使用以下代码来做同样的事情：
if AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo) == AVAuthorizationStatus.Authorized
// Already Authorized
else
AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: (granted: Bool) -> Void in
if granted == true
// User granted
else
// User rejected
)
注意：
-
确保在构建阶段的链接二进制部分添加
AVFoundation 框架
你应该在你的类上写import AVFoundation 来导入AVFoundation
SWIFT 3
if AVCaptureDevice.authorizationStatus(forMediaType: AVMediaTypeVideo) == AVAuthorizationStatus.authorized
// Already Authorized
else
AVCaptureDevice.requestAccess(forMediaType: AVMediaTypeVideo, completionHandler: (granted: Bool) -> Void in
if granted == true
// User granted
else
// User Rejected
)
斯威夫特 4
if AVCaptureDevice.authorizationStatus(for: .video) == .authorized
//already authorized
else
AVCaptureDevice.requestAccess(for: .video, completionHandler: (granted: Bool) in
if granted
//access allowed
else
//access denied
)
【讨论】：
谢谢。导入工作无需添加到链接二进制文件。但我确实在框架中有基础。有关系吗？ @Esq：您不需要链接二进制文件，因为根据 Swift Imports，任何可作为模块访问的 Objective-C 框架（或 C 库）都可以直接导入 Swift。这包括所有的 Objective-C 系统框架——例如 Foundation、UIKit 和 SpriteKit——以及系统提供的通用 C 库。圣诞快乐... 谢谢，也祝你圣诞快乐 :) 顺便说一句，在 ios7 中，此方法进入已经授权，即使它从未收到请求。为什么会这样，我该如何解决？ @Esq：如果您的应用已经拥有权限并在设置应用中进行了设置，则不会再次询问。检查您的设置应用程序是否有权限。 我在尝试之前重置了模拟器设置。去检查设置没有关于应用程序的内容。在ios7.1模拟器上试用【参考方案2】：Swift 3.0 更新解决方案
func callCamera()
let myPickerController = UIImagePickerController()
myPickerController.delegate = self;
myPickerController.sourceType = UIImagePickerControllerSourceType.camera
self.present(myPickerController, animated: true, completion: nil)
NSLog("Camera");
func checkCamera()
let authStatus = AVCaptureDevice.authorizationStatus(forMediaType: AVMediaTypeVideo)
switch authStatus
case .authorized: callCamera() // Do your stuff here i.e. callCameraMethod()
case .denied: alertPromptToAllowCameraAccessViaSetting()
case .notDetermined: alertToEncourageCameraAccessInitially()
default: alertToEncourageCameraAccessInitially()
func alertToEncourageCameraAccessInitially()
let alert = UIAlertController(
title: "IMPORTANT",
message: "Camera access required for capturing photos!",
preferredStyle: UIAlertControllerStyle.alert
)
alert.addAction(UIAlertAction(title: "Cancel", style: .default, handler: nil))
alert.addAction(UIAlertAction(title: "Allow Camera", style: .cancel, handler: (alert) -> Void in
UIApplication.shared.openURL(URL(string: UIApplicationOpenSettingsURLString)!)
))
present(alert, animated: true, completion: nil)
func alertPromptToAllowCameraAccessViaSetting()
let alert = UIAlertController(
title: "IMPORTANT",
message: "Camera access required for capturing photos!",
preferredStyle: UIAlertControllerStyle.alert
)
alert.addAction(UIAlertAction(title: "Dismiss", style: .cancel) alert in
if AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo).count > 0
AVCaptureDevice.requestAccess(forMediaType: AVMediaTypeVideo) granted in
DispatchQueue.main.async()
self.checkCamera()
)
present(alert, animated: true, completion: nil)
【讨论】：
我认为你混合了方法名 alertToEncourageCameraAccessInitially 和 alertPromptToAllowCameraAccessViaSetting ;)【参考方案3】：以下是针对 Swift 4.x 更新的清理答案：
从 iOS 10 开始，您还必须在 info.plist 文件中请求权限以避免崩溃：
隐私 - 相机使用说明
您必须提供一个字符串，该字符串使用此密钥呈现给用户。否则将导致尝试访问相机时崩溃。
import AVFoundation
func checkCameraAccess()
switch AVCaptureDevice.authorizationStatus(for: .video)
case .denied:
print("Denied, request permission from settings")
presentCameraSettings()
case .restricted:
print("Restricted, device owner must approve")
case .authorized:
print("Authorized, proceed")
case .notDetermined:
AVCaptureDevice.requestAccess(for: .video) success in
if success
print("Permission granted, proceed")
else
print("Permission denied")
func presentCameraSettings()
let alertController = UIAlertController(title: "Error",
message: "Camera access is denied",
preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "Cancel", style: .default))
alertController.addAction(UIAlertAction(title: "Settings", style: .cancel) _ in
if let url = URL(string: UIApplicationOpenSettingsURLString)
UIApplication.shared.open(url, options: [:], completionHandler: _ in
// Handle
)
)
present(alertController, animated: true)
这将测试四个可能的答案，然后如果是notDetermined，则请求权限，或者如果是denied，则将用户引导至设置以启用它。如果是restricted，当前用户可能无法启用，但您应该为他们提供某种形式的指导。
【讨论】：
【参考方案4】：这将在用户授予权限时打开相机。否则显示请求许可的警报。
func openCamera()
let authStatus = AVCaptureDevice.authorizationStatus(for: AVMediaType.video)
switch (authStatus)
case .notDetermined, .restricted, .denied:
showAlert(title: "Unable to access the Camera", message: "To enable access, go to Settings > Privacy > Camera and turn on Camera access for this app.")
case .authorized:
alert.dismiss(animated: true, completion: nil)
if(UIImagePickerController .isSourceTypeAvailable(.camera))
picker.sourceType = .camera
picker.showsCameraControls=true
picker.allowsEditing=true
self.viewController!.present(picker, animated: true, completion: nil)
在此之后调用此函数以显示警报
func showAlert(title:String, message:String)
let alert = UIAlertController(title: title,
message: message,
preferredStyle: UIAlertController.Style.alert)
let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
alert.addAction(okAction)
let settingsAction = UIAlertAction(title: "Settings", style: .default, handler: _ in
// Take the user to Settings app to possibly change permission.
guard let settingsUrl = URL(string: UIApplication.openSettingsURLString) else return
if UIApplication.shared.canOpenURL(settingsUrl)
if #available(iOS 10.0, *)
UIApplication.shared.open(settingsUrl, completionHandler: (success) in
// Finished opening URL
)
else
// Fallback on earlier versions
UIApplication.shared.openURL(settingsUrl)
)
alert.addAction(settingsAction)
self.viewController!.present(alert, animated: true, completion: nil)
【讨论】：
+1，因为它在一个小改动后对我有用。除了第一次情况 .notDetermined 为真之外，一切都很好，所以我们可以继续做我们在 .authorised 情况下所做的一切，因为它会要求允许/拒绝，或者我们可以向用户展示“AVCaptureDevice.requestAccess(for ： 。视频）”。从下一次尝试切换案例将基于第一次响应。此外，在我们第一次拒绝/允许之前，我们不会在隐私设置中看到这一点。【参考方案5】：您可以导入 AVFoundation 框架并使用 authorizationStatus(for:) 如下所示的方法并处理相应的情况。
switch AVCaptureDevice.authorizationStatus(for: .video)
case .authorized: // The user has previously granted access to the camera.
self.setupCaptureSession()
case .notDetermined: // The user has not yet been asked for camera access.
AVCaptureDevice.requestAccess(for: .video) granted in
if granted
self.setupCaptureSession()
case .denied: // The user has previously denied access.
return
case .restricted: // The user can't grant access due to restrictions.
return
【讨论】：
很好的解决方案！！【参考方案6】：我已经修改了上面的答案并删除了初始提示，因为当我们要使用设备的摄像头时，系统会自行提示权限：
func checkPermissions()
let authStatus = AVCaptureDevice.authorizationStatus(forMediaType: AVMediaTypeVideo)
switch authStatus
case .authorized:
setupCamera()
case .denied:
alertPromptToAllowCameraAccessViaSetting()
default:
// Not determined fill fall here - after first use, when is't neither authorized, nor denied
// we try to use camera, because system will ask itself for camera permissions
setupCamera()
func alertPromptToAllowCameraAccessViaSetting()
let alert = UIAlertController(title: "Error", message: "Camera access required to...", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Cancel", style: .default))
alert.addAction(UIAlertAction(title: "Settings", style: .cancel) (alert) -> Void in
UIApplication.shared.openURL(URL(string: UIApplicationOpenSettingsURLString)!)
)
present(alert, animated: true)
【讨论】：
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