我在自定义 View (cameraView) 中打开我的摄像头，它在后置摄像头上工作正常，但当我使用自定义转动 按钮 (TurnCamera) 将它切换到前置时，问题就来了，我得到以下内容:

input "AVCaptureFigVideoDevice: 0x1035c9e80 [Front Camera][com.apple.avfoundation.avcapturedevice.built-in_video:1]"

但是我的自定义摄像头 View 仍然显示后置摄像头，并且得到 captureSession.canAddInput(input) = false，我是否应该为前置摄像头授予对 info.plist 的任何访问权限。

我打开相机的代码是:-

func camera(){
        let devices = AVCaptureDevice.devices(for: AVMediaType.video)

        currentCaptureDevice = (usingFrontCamera ? getFrontCamera() : getBackCamera())

        print(currentCaptureDevice)

        for device in devices{

            do{
                let input = try AVCaptureDeviceInput(device: currentCaptureDevice!)
                    if captureSession.canAddInput(input){

                        captureSession.addInput(input)
                        sessionOutput.outputSettings = [AVVideoCodecKey: AVVideoCodecJPEG]

                        if captureSession.canAddOutput(sessionOutput){

                            captureSession.startRunning()
                            captureSession.addOutput(sessionOutput)
                            previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                            previewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
                            previewLayer.connection?.videoOrientation = AVCaptureVideoOrientation.portrait
                            cameraView.layer.addSublayer(previewLayer)
                            previewLayer.position = CGPoint(x: self.cameraView.frame.width/2, y: self.cameraView.frame.height/2)
                            cameraView.contentMode = .scaleToFill
                            previewLayer.bounds = cameraView.frame
                        }
                    }
                }
                catch{

                    print("error")
            }
        }
    }

获取后置摄像头的功能是:-

func getBackCamera() -> AVCaptureDevice{
        return AVCaptureDevice.default(for: AVMediaType.video)!
    }

获取前置摄像头的函数是:-

func getFrontCamera() -> AVCaptureDevice?{
        let videoDevices = AVCaptureDevice.devices(for: AVMediaType.video)

        for device in videoDevices{
            let device = device as! AVCaptureDevice
            if device.position == AVCaptureDevice.Position.front {
                return device
            }
        }
        return nil
    }

切换摄像头的按钮操作:-

@IBAction func TurnCamera(_ sender: UIButton) {

        usingFrontCamera = !usingFrontCamera
        camera()

    }

在 :- https://www.dropbox.com/s/6cfmbh3tnw5y4f7/SwitchingCamera.zip?dl=0 上查找演示项目

提前致谢

最佳答案

我得到了答案，当从后切换到前时，我没有删除捕获 session 输入。

我只修改了两个函数 1:- 较早

func getBackCamera() -> AVCaptureDevice{
        return AVCaptureDevice.default(for: AVMediaType.video)!
    }

现在，

func getBackCamera() -> AVCaptureDevice{

        for i in captureSession.inputs {
            captureSession.removeInput(i as! AVCaptureInput)
        }

        return AVCaptureDevice.default(for: AVMediaType.video)!
    }

2:- 早些时候，

func getFrontCamera() -> AVCaptureDevice?{
        let videoDevices = AVCaptureDevice.devices(for: AVMediaType.video)

        for device in videoDevices{
            let device = device as! AVCaptureDevice
            if device.position == AVCaptureDevice.Position.front {
                return device
            }
        }
        return nil
    }

现在，

func getFrontCamera() -> AVCaptureDevice?{

        for i in captureSession.inputs {
            captureSession.removeInput(i as! AVCaptureInput)
        }

        let videoDevices = AVCaptureDevice.devices(for: AVMediaType.video)

        for device in videoDevices{
            let device = device
            if device.position == AVCaptureDevice.Position.front {

                return device

            }
        }
        return nil
    }

获取演示:- https://www.dropbox.com/s/p6opina5gtg8nvd/Updated%20Switching%20Camera%202.zip?dl=0

关于ios - 无法在前置摄像头的情况下添加输入，将摄像头从后切换到前置？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54801539/