I have a view controller where I'm trying to open a camera to scan a QR code. Every time I open the VC it crashes my app with an error message:
This app has crashed because it attempted to access privacy-sensitive data without a usage description. The app's Info.plist must contain an NSCameraUsageDescription key with a string value explaining to the user how the app uses this data.
I have double-checked my info.plist and in Target as well. I have permitted the camera usage already, but still facing the same error every time. What is the missing dot? Here is my VC code:
import UIKit
import AVFoundation
class Scanner__VC: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
var captureSession: AVCaptureSession!
var previewLayer: AVCaptureVideoPreviewLayer!
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.black
captureSession = AVCaptureSession()
guard let videoCaptureDevice = AVCaptureDevice.default(for: .video) else { return }
let videoInput: AVCaptureDeviceInput
do {
videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
} catch {
return
}
if (captureSession.canAddInput(videoInput)) {
captureSession.addInput(videoInput)
} else {
failed()
return
}
let metadataOutput = AVCaptureMetadataOutput()
if (captureSession.canAddOutput(metadataOutput)) {
captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
metadataOutput.metadataObjectTypes = [.qr]
} else {
failed()
return
}
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.frame = view.layer.bounds
previewLayer.videoGravity = .resizeAspectFill
view.layer.addSublayer(previewLayer)
captureSession.startRunning()
}
func failed() {
let ac = UIAlertController(title: "Scanning not supported", message: "Your device does not support scanning a code from an item. Please use a device with a camera.", preferredStyle: .alert)
ac.addAction(UIAlertAction(title: "OK", style: .default))
present(ac, animated: true)
captureSession = nil
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if (captureSession?.isRunning == false) {
captureSession.startRunning()
}
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if (captureSession?.isRunning == true) {
captureSession.stopRunning()
}
}
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
captureSession.stopRunning()
if let metadataObject = metadataObjects.first {
guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else { return }
guard let stringValue = readableObject.stringValue else { return }
AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
found(code: stringValue)
}
dismiss(animated: true)
}
func found(code: String) {
print(code)
}
override var prefersStatusBarHidden: Bool {
return true
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
return .portrait
}
func showAlert(with message: String) {
let alert = UIAlertController(title: "QR Code Scanned", message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default))
present(alert, animated: true)
}
You have:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>UIApplicationSceneManifest</key>
<dict>
<key>NSCameraUsageDescription</key>
<string>Camera usage reason</string>
<key>UIApplicationSupportsMultipleScenes</key>
<false/>
<key>UISceneConfigurations</key>
<dict>
<key>UIWindowSceneSessionRoleApplication</key>
<array>
<dict>
<key>UISceneConfigurationName</key>
<string>Default Configuration</string>
<key>UISceneDelegateClassName</key>
<string>$(PRODUCT_MODULE_NAME).SceneDelegate</string>
<key>UISceneStoryboardFile</key>
<string>Main</string>
</dict>
</array>
</dict>
</dict>
</dict>
</plist>
For the next use of NSCameraUsageDescription
in my answer, it can be applied to the PhotoLibrary & the two Location permissions too.
NSCameraUsageDescription
is inside UIApplicationSceneManifest
(in a hierarchy level speaking), while it should be at the top hierarchy of the plist, on the same level as UIApplicationSceneManifest
.
You should have something like that:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>NSCameraUsageDescription</key>
<string>Camera usage reason</string>
<key>UIApplicationSceneManifest</key>
<dict>
<key>UIApplicationSupportsMultipleScenes</key>
<false/>
<key>UISceneConfigurations</key>
<dict>
<key>UIWindowSceneSessionRoleApplication</key>
<array>
<dict>
<key>UISceneConfigurationName</key>
<string>Default Configuration</string>
<key>UISceneDelegateClassName</key>
<string>$(PRODUCT_MODULE_NAME).SceneDelegate</string>
<key>UISceneStoryboardFile</key>
<string>Main</string>
</dict>
</array>
</dict>
</dict>
</dict>
</plist>
I put it before the UIApplicationSceneManifest
to highlight the fact that they are at the same hierarchy level, but it could be afterward, it doesn't matter, it's a key access (dictionary), not index access (array)