我正在尝试制作视频预览层，它似乎正在工作，但是屏幕上没有任何显示。这是我使用的代码：
var captureSession = AVCaptureSession()
var backCamera: AVCaptureDevice?
var frontCamera: AVCaptureDevice?
var currentCamera: AVCaptureDevice?
var photoOutput: AVCapturePhotoOutput?
var cameraPreviewLayer: AVCaptureVideoPreviewLayer?
//UIOutlets
@IBOutlet weak var cameraView: UIView!
@IBOutlet weak var captureImageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view
self.cameraSetupSession()
self.setupDevice()
self.setupInputOutput()
self.setupPerviewLayer()
self.startRunningCaptureSession()
}
func cameraSetupSession() {
print("1")
captureSession.sessionPreset = AVCaptureSession.Preset.photo
}
func setupDevice() {
print("2")
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera], mediaType: .video , position: .unspecified)
let devices = deviceDiscoverySession.devices
for device in devices{
if device.position == .back{
backCamera = device
}else if device.position == .front{
frontCamera = device
}
}
currentCamera = backCamera
}
func setupInputOutput() {
print("3")
do{
let captureDeviceInput = try AVCaptureDeviceInput(device: currentCamera!)
captureSession.addInput(captureDeviceInput)
photoOutput?.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format:[AVVideoCodecKey:AVVideoCodecType.jpeg])], completionHandler: nil)
}catch{
displayAlert(title: "Error", message: "There was an error acseesing your camera feed.", okMessage: "Okay")
}
}
func setupPerviewLayer() {
print("4")
cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
cameraPreviewLayer?.videoGravity = .resizeAspectFill
cameraPreviewLayer?.masksToBounds = true
cameraPreviewLayer?.connection?.videoOrientation = .portrait
self.view.layer.insertSublayer(cameraPreviewLayer!, at: 0)
}
func startRunningCaptureSession() {
print("5")
self.captureSession.startRunning()
print(self.captureSession.isRunning)
}`
在此期间，我的日志输出是：
1个
2
2017-11-23 12：36：04.042296-0500 Instagram克隆[353：15568] [MC] systemgroup.com.apple.configurationprofiles路径的系统组容器为/private/var/containers/Shared/SystemGroup/systemgroup.com。苹果配置文件
2017-11-23 12：36：04.043014-0500 Instagram克隆[353：15568] [MC]从公共有效用户设置中读取。
3
4
5
真正
我仅有的积极迹象之一是，当我删除并清洁应用程序时，它的确要求允许使用相机。拜托，我们非常感谢任何想法和帮助。
最佳答案
查看代码，我可以看到的一件事是您没有将会话链接到预览层。
尝试将以下内容添加到setupPerviewLayer（）
cameraPreviewLayer?.session = captureSession