ios - 使用 AVFoundation 终止应用程序错误的自定义相机 - SWIFT 4

Question

我正在尝试在 Swift 4、Xcode 9 和 AVFoundation 中制作一个自定义相机，我已经编写了所有代码来制作它，以便应用程序的 previewLayer 显示，你可以捕捉一个photo 但是当我运行它时没有任何反应并且我收到终止应用程序错误:

2018-08-10 09:06:31.160691+0200 Yubi[313:12221] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key previewView.'

这是我编写的代码。我只有 1 个 ViewController 用于 1 个带有捕获按钮的 Storyboard和一个用于 previewLayer 的 UIView:

import UIKit
import Foundation
import AVFoundation

class CameraViewController: UIViewController {

    //This is the IBoutlet for the camera view (so the live feed of what u see)
    @IBOutlet weak var cameraView: UIView!
    @IBOutlet weak var button: UIButton!

    var captureSession = AVCaptureSession()
    var sessionOutput = AVCapturePhotoOutput()
    var previewLayer = AVCaptureVideoPreviewLayer()

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

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

        //To get a devie session and choose what side camera i think. In the Devicetypes: i am declaring what type of camera im looking for in the telephones devices (so functional pieces of hardware)
        let deviceSession = AVCaptureDevice.DiscoverySession(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera,.builtInDualCamera,.builtInTelephotoCamera], mediaType: AVMediaType.video, position: .unspecified)

        for device in (deviceSession.devices) {

            if device.position == AVCaptureDevice.Position.front {

                do {

                    let input = try AVCaptureDeviceInput(device: device)

                    if captureSession.canAddInput(input){
                        captureSession.addInput(input)

                        if captureSession.canAddOutput(sessionOutput){
                            captureSession.addOutput(sessionOutput)

                            previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                            previewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
                            previewLayer.connection?.videoOrientation = .portrait


                            cameraView.layer.addSublayer(previewLayer)
                            cameraView.addSubview(button)


                            previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)

                            previewLayer.bounds = cameraView.frame

                            captureSession.startRunning()

                        }
                    }


                } catch let avError {
                    print(avError)
                }

            }

        }


    }

    //if let cameraID = AVCaptureDevice.DiscoverySession(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera], mediaType: AVMediaType.video, position: AVCaptureDevice.Position.front).devices.first?.localizedName{
    //cameraID = "Front Camera"


    //This is for the actuall take photo button
    @IBAction func takePhoto(_ sender: Any) {



    }

}

Answer 1

检查您的 socket 连接。有一个 Controller 对象连接到“previewView”，但它不是在您的 Controller 中创建的。删除该连接并尝试。它会起作用。

You will see previewView with mobile type icon which mean that is not declared in controller. Check attached image to remove that.