在 UIView 的背景上设置摄像头

Question

我正在尝试在 UIViewController 的 UIView 背景上设置摄像头，以便能够在其上绘图。

怎么做？

Answer 1

一种简单的方法是在 imagepickercontroller 上添加叠加视图并隐藏默认视图。

另一种方法是使用 AV 框架，这将为您提供更多选择和自由。

选择取决于您的需要。

Answer 2

更新为 SWIFT 5

您可以尝试这样的操作：

我在 UIViewController 的主视图中添加了两个 UIView，一个叫做 previewView（用于相机），另一个 UIView 叫做 boxView（在摄像机视图上方）

class ViewController: UIViewController {

    var previewView : UIView!
    var boxView:UIView!

    //Camera Capture requiered properties
    var videoDataOutput: AVCaptureVideoDataOutput!
    var videoDataOutputQueue: DispatchQueue!
    var previewLayer:AVCaptureVideoPreviewLayer!
    var captureDevice : AVCaptureDevice!
    let session = AVCaptureSession()
    var currentFrame: CIImage!
    var done = false

    override func viewDidLoad() {
        super.viewDidLoad()
        previewView = UIView(frame: CGRect(x: 0, y: 0, width:  UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height))
        previewView.contentMode = .scaleAspectFit
        view.addSubview(previewView)

        //Add a box view
        boxView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 200))
        boxView.backgroundColor = UIColor.green
        boxView.alpha = 0.3
        view.addSubview(boxView)

        self.setupAVCapture()
    }

    override func viewWillAppear(_ animated: Bool) {
        if !done {
            session.startRunning()
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    override var shouldAutorotate: Bool {
        if (UIDevice.current.orientation == UIDeviceOrientation.landscapeLeft ||
        UIDevice.current.orientation == UIDeviceOrientation.landscapeRight ||
            UIDevice.current.orientation == UIDeviceOrientation.unknown) {
            return false
        }
        else {
            return true
        }
    }
}


// AVCaptureVideoDataOutputSampleBufferDelegate protocol and related methods
extension ViewController:  AVCaptureVideoDataOutputSampleBufferDelegate{
    func setupAVCapture(){
        session.sessionPreset = AVCaptureSession.Preset.vga640x480
        guard let device = AVCaptureDevice
        .default(AVCaptureDevice.DeviceType.builtInWideAngleCamera,
                 for: .video,
                 position: AVCaptureDevice.Position.front) else{
                            return
        }
        captureDevice = device
        beginSession()
        done = true
    }

    func beginSession(){
        var deviceInput: AVCaptureDeviceInput!
        do {
            deviceInput = try AVCaptureDeviceInput(device: captureDevice)
            guard deviceInput != nil else {
                print("error: cant get deviceInput")
                return
            }

            if self.session.canAddInput(deviceInput){
                self.session.addInput(deviceInput)
            }

            videoDataOutput = AVCaptureVideoDataOutput()
            videoDataOutput.alwaysDiscardsLateVideoFrames=true
            videoDataOutputQueue = DispatchQueue(label: "VideoDataOutputQueue")
            videoDataOutput.setSampleBufferDelegate(self, queue:self.videoDataOutputQueue)

            if session.canAddOutput(self.videoDataOutput){
                session.addOutput(self.videoDataOutput)
            }

            videoDataOutput.connection(with: AVMediaType.video)?.isEnabled = true

            self.previewLayer = AVCaptureVideoPreviewLayer(session: self.session)
            self.previewLayer.videoGravity = AVLayerVideoGravity.resizeAspect

            let rootLayer: CALayer = self.previewView.layer
            rootLayer.masksToBounds = true
            self.previewLayer.frame = rootLayer.bounds
            rootLayer.addSublayer(self.previewLayer)
            session.startRunning()
        } catch let error as NSError {
            deviceInput = nil
            print("error: \(error.localizedDescription)")
        }
    }

    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
        currentFrame =   self.convertImageFromCMSampleBufferRef(sampleBuffer)
    }


    // clean up AVCapture
    func stopCamera(){
        session.stopRunning()
        done = false
    }

    func convertImageFromCMSampleBufferRef(_ sampleBuffer:CMSampleBuffer) -> CIImage{
        let pixelBuffer: CVPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)!
        let ciImage:CIImage = CIImage(cvImageBuffer: pixelBuffer)
        return ciImage
    }
}

您可以将 boxView 的 frame 替换为 mainView 的 frame，并且不要设置其背景属性。这样你就可以使用这个视图来添加更多的子视图了。

IMPORTANT

Remember that in iOS 10 you need to first ask the user for permission in order to have access to the camera. You do this by adding a usage key to your app’s Info.plist together with a purpose string because if you fail to declare the usage, your app will crash when it first makes the access.

这是显示相机访问请求的屏幕截图

希望对您有所帮助！

Answer 3

另一方面，SceneView 对增强现实应用程序很有用。

用AVFramework或UIView创建一个预览层，然后添加预览图层到视图的子图层。
创建并自定义场景视图。然后将场景视图添加到视图的子视图。

创建和自定义场景。最后添加到scenview的场景中。

    // 1. Create a preview layer with AVFramework or UIView, then add preview layer to view's sublayer.
    self.previewLayer!.frame = view.layer.bounds
    view.clipsToBounds = true
    view.layer.addSublayer(self.previewLayer!)



    // 2. Create and custumize a sceneview. Then add sceneview to view's subview.
    let sceneView = SCNView()
    sceneView.frame = view.bounds
    sceneView.backgroundColor = UIColor.clearColor()
    self.previewLayer!.frame = view.bounds
    view.addSubview(sceneView)

    //   3 . Create and custimize scene. Finally add to scenview's scene.
    let scene = SCNScene()
    sceneView.autoenablesDefaultLighting = true
    sceneView.allowsCameraControl = true
    let boxGeometry = SCNBox(width: 800 , height: 400, length: 1.0, chamferRadius: 1.0)
    let yellow = UIColor.yellowColor()
    let semi = yellow.colorWithAlphaComponent(0.3)
    boxGeometry.firstMaterial?.diffuse.contents = semi
    let boxNode = SCNNode(geometry: boxGeometry)
    scene.rootNode.addChildNode(boxNode)
    sceneView.scene = scene

在 UIView 的背景上设置摄像头

Set up camera on the background of UIView

camera

ios

swift