Ios 将“切换摄影机”按钮添加到自定义摄影机视图

我从GitHub获得了这段代码，作为最基本的自定义相机视图控制器。我已经实现了一个闪光灯，如果我测试前后摄像头，它就会工作。但我如何实现一个按钮，让你在应用程序中切换相机？我已经创建了一个摄像头按钮按下动作，当点击摄像头开关按钮时，该动作将运行

class CameraViewController: UIViewController {

@IBOutlet weak var flashButton: UIButton!
@IBOutlet weak var cameraButton: UIButton!

var flashOn = false

@IBOutlet weak var previewView: PreviewView!


let captureSession = AVCaptureSession()
var videoPreviewLayer: AVCaptureVideoPreviewLayer?
let capturePhotoOutput = AVCapturePhotoOutput()
let capturePhotoDelegate = CapturePhotoDelegate()

private var deviceInput: AVCaptureDeviceInput?
private var cameraPosition: CameraPosition = .back

enum CameraPosition {
    case front
    case back
}

override func viewDidLoad() {
    super.viewDidLoad()
    checkCameraUsagePermission()

    flashButton.setTitle("OFF", for: .normal)
    cameraButton.setTitle("BACK", for: .normal)
}

func initialiseCaptureSession() {

    let captureDevice = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .unspecified)

    guard let input = try? AVCaptureDeviceInput(device: captureDevice!),
        captureSession.canAddInput(input)
        else { return }

    captureSession.addInput(input)
    self.previewView.videoPreviewLayer.session = self.captureSession
    self.previewView.videoPreviewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill

    capturePhotoOutput.isHighResolutionCaptureEnabled = true
    captureSession.addOutput(capturePhotoOutput)

    captureSession.startRunning()
}

@IBAction func onTapTakePhoto(_ sender: UIButton) {

    let photoSettings = AVCapturePhotoSettings()
    photoSettings.isAutoStillImageStabilizationEnabled = true
    photoSettings.isHighResolutionPhotoEnabled = true
    photoSettings.flashMode = .auto
    if flashOn == true {
        photoSettings.flashMode = .on
    } else if flashOn == false {
        photoSettings.flashMode = .off
    }
    capturePhotoOutput.capturePhoto(with: photoSettings, delegate: capturePhotoDelegate)
}

func checkCameraUsagePermission() {
    switch AVCaptureDevice.authorizationStatus(for: .video) {
    case .authorized:
        self.initialiseCaptureSession()

    case .notDetermined:
        AVCaptureDevice.requestAccess(for: .video) { granted in
            if granted {
                self.initialiseCaptureSession()
            }
        }
    case .denied:
        return
    case .restricted:
        return
    }
}

@IBAction func flashButtonPressed(_ sender: UIButton) {
    if flashOn == false {
        flashOn = true
        flashButton.setTitle("ON", for: .normal)
    } else {
        flashOn = false
        flashButton.setTitle("OFF", for: .normal)

    }

}

func addVideoInput(position: AVCaptureDevice.Position) {
    guard let device: AVCaptureDevice = AVCaptureDevice.default(.builtInWideAngleCamera,
        for: .video, position: position) else { return }
    if let currentInput = self.deviceInput {
        self.captureSession.removeInput(currentInput)
        self.deviceInput = nil
    }
    do {
        let input = try AVCaptureDeviceInput(device: device)
        if self.captureSession.canAddInput(input) {
            self.captureSession.addInput(input)
            self.deviceInput = input
        }
    } catch {
        print(error)
    }
}

@IBAction func cameraButtonPressed(_ sender: UIButton) {
    switch self.cameraPosition {
    case .front:
        self.cameraPosition = .back
        self.addVideoInput(position: .back)
    case .back:
        self.cameraPosition = .front
        self.addVideoInput(position: .front)
    }
    //configure your session here
    DispatchQueue.main.async {
        self.captureSession.beginConfiguration()
        if self.captureSession.canAddOutput(self.capturePhotoOutput) {
            self.captureSession.addOutput(self.capturePhotoOutput)
        }
        self.captureSession.commitConfiguration()
    }
}

---

}

首先，将您的

AVCaptureDeviceInput

存储在属性中

专用var设备输入：AVCaptureDeviceInput？

下一步创建枚举，该枚举将指示哪个摄影机处于活动状态

enum CameraPosition {
    case front
    case back
}

和当前相机模式的属性

private var cameraPosition: CameraPosition = .back

现在创建负责摄像机切换的功能

func addVideoInput(position: AVCaptureDevice.Position) {
    guard let device: AVCaptureDevice = AVCaptureDevice.default(.builtInWideAngleCamera,
        for: .video, position: position) else { return }
    if let currentInput = self.deviceInput {
        self.captureSession.removeInput(currentInput)
        self.deviceInput = nil
    }
    do {
        let input = try AVCaptureDeviceInput(device: device)
        if self.captureSession.canAddInput(input) {
            self.captureSession.addInput(input)
            self.deviceInput = input
        }
    } catch {
        print(error)
    }
}

现在，在

camerarbutton按下的方法中，您可以切换摄像机

@IBAction func cameraButtonPressed(_ sender: UIButton) {
    switch self.cameraPosition {
        case .front:
            self.cameraPosition = .back
            self.addVideoInput(position: .back)
        case .back:
            self.cameraPosition = .front
            self.addVideoInput(position: .front)
    }
    //configure your session here
    DispatchQueue.main.async { 
        self.captureSession.beginConfiguration()
        if self.captureSession.canAddOutput(self.capturePhotoOutput) {
            self.captureSession.addOutput(self.capturePhotoOutput)
        }
        self.captureSession.commitConfiguration()
    }
}

非常感谢你的回答。我对编程非常陌生，一定没有正确地实现您的代码，因为我仍然无法让相机翻转。我应该简单地添加您的代码还是用它替换我的一些代码？对不起，只需添加我的代码。有关更多信息，请参阅我的GitHub repo。应用程序没有崩溃，但相机没有切换。您是否存储了设备输入？请提供您的更新代码什么是存储设备输入？