Question

我正在我的应用中创建一个二维码扫描器。它包括导航栏，QRcode摄像头和结果框。这就是我想要做的。 With navigation bar

但是当我在手机中运行时，导航栏位于相机框架后面。 Without navigation bar

我尝试将导航栏的插座插入到我的代码中并插入添加view.bringSubview(toFront: navigationbar)但Xcode表示它不是UIview所以我收到错误。我是IOS开发的新手，我们将不胜感激。

以下是我的代码的一部分：

    var captureSession:AVCaptureSession?
    var videoPreviewLayer:AVCaptureVideoPreviewLayer?
    var qrCodeFrameView:UIView?
     @IBOutlet weak var messageLabel: UILabel!
    // Added to support different barcodes
    let supportedBarCodes = [AVMetadataObjectTypeQRCode, AVMetadataObjectTypeCode128Code, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode93Code, AVMetadataObjectTypeUPCECode, AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeAztecCode]

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        let captureDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)

        do {
            // Get an instance of the AVCaptureDeviceInput class using the previous device object.
            let input = try AVCaptureDeviceInput(device: captureDevice)

            // Initialize the captureSession object.
            captureSession = AVCaptureSession()
            // Set the input device on the capture session.
            captureSession?.addInput(input)

            // Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
            let captureMetadataOutput = AVCaptureMetadataOutput()
            captureSession?.addOutput(captureMetadataOutput)

            // Set delegate and use the default dispatch queue to execute the call back
            captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)

            // Detect all the supported bar code
            captureMetadataOutput.metadataObjectTypes = supportedBarCodes

            // Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
            videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
            videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
            videoPreviewLayer?.frame = view.layer.bounds
            view.layer.addSublayer(videoPreviewLayer!)

            // Start video capture
            captureSession?.startRunning()

            // Move the message label to the top view
            view.bringSubview(toFront: messageLabel)

            // Initialize QR Code Frame to highlight the QR code
            qrCodeFrameView = UIView()

            if let qrCodeFrameView = qrCodeFrameView {
                qrCodeFrameView.layer.borderColor = UIColor.green.cgColor
                qrCodeFrameView.layer.borderWidth = 2
                view.addSubview(qrCodeFrameView)
                view.bringSubview(toFront: qrCodeFrameView)
            }

        } catch {
            // If any error occurs, simply print it out and don't continue any more.
            print(error)
            return
        }

Answer 1

尝试替换此：

view.layer.addSublayer(videoPreviewLayer!)

使用：

view.layer.insertSublayer(videoPreviewLayer!, below: qrCodeFrameView.layer) //Or below: messageLabel.layer

尽量不要将子图层添加到顶部，而只是将其插入已经存在的其他子视图下方，它将确保导航栏正确显示

如何将导航栏放在相机框架的顶部？

1 个答案: