CapturePhoto is not working swift 3

Question

I am trying to build a camera application. As I am new in iOS, I read documentations, watched tutorials and wrote the following codes:

import UIKit
import AVFoundation
class StartVC: UIViewController {

var connection: AVCaptureConnection!
var output: AVCapturePhotoOutput!
var videoPreviewLayer: AVCaptureVideoPreviewLayer!
@IBOutlet var videoPreviewView: UIView!

override func viewDidLoad() {
    super.viewDidLoad()

    self.createCamera()
}

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    self.videoPreviewLayer.bounds = self.videoPreviewView.bounds
    self.videoPreviewLayer.position = CGPoint(x: self.videoPreviewView.bounds.midX, y: self.videoPreviewView.bounds.midY)
}

func createCamera() {
    let captureSession = AVCaptureSession()

    if captureSession.canSetSessionPreset(AVCaptureSessionPresetHigh) {
        captureSession.sessionPreset = AVCaptureSessionPresetHigh
    } else {
        print("Error: Couldn't set preset = \(AVCaptureSessionPresetHigh)")
        return
    }

    let cameraDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)

    var error: NSError?

    let inputDevice = try! AVCaptureDeviceInput.init(device: cameraDevice)
    //let inputDevice = AVCaptureDeviceInput.withDevice(cameraDevice) as AVCaptureDeviceInput
    if let error = error {
        print("Error: \(error)")
        return
    }

    if captureSession.canAddInput(inputDevice) {
        captureSession.addInput(inputDevice)
    } else {
        print("Error: Couldn't add input device")
        return
    }

    let imageOutput = AVCapturePhotoOutput()
    if captureSession.canAddOutput(imageOutput) {
        captureSession.addOutput(imageOutput)
    } else {
        print("Error: Couldn't add output")
        return
    }

    // Store imageOutput. We will need it to take photo
    self.output = imageOutput

    let connection = imageOutput.connections.first as! AVCaptureConnection!
    // Store this connection in property. We will need it when we take image.
    self.connection = connection
    connection?.videoOrientation = AVCaptureVideoOrientation.portrait

    captureSession.startRunning()

    // This will preview the camera
    let videoLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    videoLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
    videoLayer?.contentsScale = UIScreen.main.scale

    self.videoPreviewView.layer.addSublayer(videoLayer!)

    // Store this layer instance in property. We will place it into a view
    self.videoPreviewLayer = videoLayer
}



@IBAction func CaptureButton(_ sender: UIButton) {

    let captureSettings = AVCapturePhotoSettings()
    let previewPixelType = captureSettings.availablePreviewPhotoPixelFormatTypes.first!
    let previewFormat = [kCVPixelBufferPixelFormatTypeKey as String: previewPixelType,
                         kCVPixelBufferWidthKey as String: 300,
                         kCVPixelBufferHeightKey as String: 300,
                         ]
    captureSettings.previewPhotoFormat = previewFormat

    self.output.capturePhoto(with: captureSettings, delegate: self as! AVCapturePhotoCaptureDelegate)

}

}

But I am getting the error in this section.

@IBAction func CaptureButton(_ sender: UIButton) {

    let captureSettings = AVCapturePhotoSettings()
    let previewPixelType = captureSettings.availablePreviewPhotoPixelFormatTypes.first!
    let previewFormat = [kCVPixelBufferPixelFormatTypeKey as String: previewPixelType,
                         kCVPixelBufferWidthKey as String: 300,
                         kCVPixelBufferHeightKey as String: 300,
                         ]
    captureSettings.previewPhotoFormat = previewFormat

// For this line
        self.output.capturePhoto(with: captureSettings, delegate: self as! AVCapturePhotoCaptureDelegate)

    }

The error is saying that it could not cast the value of myViewController to AVCapturePhotoCaptureDelegate

How can I solve this problem?

Answer 1

Try this

class StartVC: UIViewController {
}
extension StartVC: AVCapturePhotoCaptureDelegate{
}

no need of casting

self.output.capturePhoto(with: captureSettings, delegate: self)

It can be also written as

class StartVC: UIViewController,AVCapturePhotoCaptureDelegate {


}

Answer 2

Try to add "Privacy - Camera Usage Description" key in info.plist. If you are using iOS 10+.

This key is required for accessing camera from the our app.

Answer 3

This error is because you did not confirmed AVCapturePhotoCaptureDelegate to your viewController in which you have written this code.

To solve this error please add 'AVCapturePhotoCaptureDelegate' in your class declaration like below:

class myViewController: UIViewController,AVCapturePhotoCaptureDelegate{


}