如何在 Swift 2 中切换到前置摄像头？答案

【问题标题】：How to switch to front camera in Swift 2?如何在 Swift 2 中切换到前置摄像头？
【发布时间】：2016-03-31 20:47:52
【问题描述】：

我的 ViewDidAppear 中有所有这些代码

captureSession = AVCaptureSession()


   // let backCamera = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    var captureDevice:AVCaptureDevice! = nil
    if (camera == CameraType.Front) {
        let videoDevices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)

        for device in videoDevices{
            let device = device as! AVCaptureDevice
            if device.position == AVCaptureDevicePosition.Front {
                captureDevice = device
                break
            }
        }
    } else {
        captureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
    }

    do {
        let input = try? AVCaptureDeviceInput(device: captureDevice)

        if (captureSession?.canAddInput(input) != nil){

            captureSession?.addInput(input)

            stillImageOutput = AVCaptureStillImageOutput()
            stillImageOutput?.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]

            if (captureSession?.canAddOutput(stillImageOutput) != nil){
                captureSession?.addOutput(stillImageOutput)

                previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)

                previewLayer?.videoGravity = AVLayerVideoGravityResizeAspect
                previewLayer?.connection.videoOrientation = AVCaptureVideoOrientation.Portrait
                cameraView.layer.addSublayer(previewLayer!)
                captureSession?.startRunning()

            }

            cameraView.bringSubviewToFront(actionView)
            previewImageView.bringSubviewToFront(actionView)
            self.previewImageView.hidden = true


        }
    }

【问题讨论】：

标签： ios swift swift2 avcapturedevice

【解决方案1】：

Xcode 8.2.1 • Swift 3.0.2

captureDevice = (AVCaptureDevice.devices() as? [AVCaptureDevice])?
                    .filter({ $0.hasMediaType(AVMediaTypeVideo) && $0.position == .front}).first

斯威夫特 2

captureDevice = (AVCaptureDevice.devices()
    .filter{ $0.hasMediaType(AVMediaTypeVideo) && $0.position == .Front})
    .first as? AVCaptureDevice

【讨论】：

【解决方案2】：

你试过了吗：

let device = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
            .map { $0 as! AVCaptureDevice }
            .filter { $0.position == .Front}
            .first!

【讨论】：

AVCaptureDevice.devicesWithMediaType 在 iOS 10 中已被弃用。Apple 建议使用 AVCaptureDevice.DiscoverySession 来确定可用的设备。文档链接：https://developer.apple.com/documentation/avfoundation/avcapturedevice/discoverysession