git地址 https://github.com/wangxiaobai1840/NativeScan

在项目使用过程中有有一些新的改动，再次添加一下
修改: 1、修改聚焦模式 2、添加闪光灯开启与关闭方法
相机配置相关

    self.scanDevice = AVCaptureDevice.default(for: .video)
        do {
            self.scanInput = try? AVCaptureDeviceInput(device: self.scanDevice!)
            guard self.scanInput != nil else {
                return
            }
            self.scanOutput = AVCaptureMetadataOutput()
            self.scanOutput?.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
            self.scanSession = AVCaptureSession()
            if self.scanDevice?.supportsSessionPreset(AVCaptureSession.Preset.hd4K3840x2160) == true{
                self.scanSession?.canSetSessionPreset(.high)
            }else if scanDevice?.supportsSessionPreset(AVCaptureSession.Preset.hd4K3840x2160) == false{
                if scanDevice?.supportsSessionPreset(AVCaptureSession.Preset.hd1920x1080) == true {
                    self.scanSession?.canSetSessionPreset(.hd1920x1080)
                }else{
                    self.scanSession?.canSetSessionPreset(.hd1280x720)
                }
            }
            
            if (self.scanSession?.canAddInput(self.scanInput!))! {
                self.scanSession?.addInput(self.scanInput!)
            }
            if (self.scanSession?.canAddOutput(self.scanOutput!))! {
                self.scanSession?.addOutput(self.scanOutput!)
            }
            
            self.scanOutput?.metadataObjectTypes = [
                AVMetadataObject.ObjectType.qr,
                AVMetadataObject.ObjectType.code39,
                AVMetadataObject.ObjectType.code128,
                AVMetadataObject.ObjectType.code39Mod43,
                AVMetadataObject.ObjectType.code93,
                AVMetadataObject.ObjectType.ean8,
                AVMetadataObject.ObjectType.ean13
            ]
            
            self.scanPreviewLayer = AVCaptureVideoPreviewLayer(session:self.scanSession!)
            self.scanPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
            self.scanPreviewLayer?.frame = self.view.layer.bounds
            view.layer.insertSublayer(self.scanPreviewLayer!, at: 0)
            if (self.scanDevice?.isFocusModeSupported(.autoFocus))! {
                do{
                    try self.scanInput?.device.lockForConfiguration()
                }catch{}
// 之前使用autoFocus自动聚焦，发现有时候聚焦不好的时候不会自动的持续聚焦，所以换为continuousAutoFocus ，这个方式可以在聚焦不清晰的时候自动的持续聚焦，知道清晰
               //  self.scanInput?.device.focusMode = .autoFocus // 自动聚焦
                self.scanInput?.device.focusMode = .continuousAutoFocus // 持续自动聚焦
                self.scanInput?.device.unlockForConfiguration()
            }
           
            if !(self.scanSession?.isRunning)! {
                self.scanSession?.startRunning()
            }
            // 注意扫描区域设置要在扫描startRunning之后
            self.scanOutput?.rectOfInterest =
            (self.scanPreviewLayer?.metadataOutputRectConverted(fromLayerRect:self.scanRect()))! // 设置扫描区域
        } catch {
            return
        }

界面相关

  func createScanView(){
        
        if scanBgView == nil {
            self.scanBgView = UIView()
            self.scanBgView?.frame = self.view.frame
            self.scanBgView?.backgroundColor = UIColor.clear
            self.view.addSubview(self.scanBgView!)
            let topView = UIView()
            topView.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.4)
            topView.frame = CGRect(x: 0, y: 0, width: KScreenWidth, height: (KScreenHeight - ALScanWidth)/2)
            self.scanBgView?.addSubview(topView)
            
            let leftView = UIView()
            leftView.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.4)
            leftView.frame = CGRect(x: 0, y: ALScanViewY, width:ALScanViewX, height: ALScanWidth)
            self.scanBgView?.addSubview(leftView)
            
            let rightView = UIView()
            rightView.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.4)
            rightView.frame = CGRect(x: ALScanViewX + ALScanWidth , y: ALScanViewY, width:ALScanViewX, height: ALScanWidth)
            self.scanBgView?.addSubview(rightView)
            
            let bottomView = UIView()
            bottomView.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.4)
            bottomView.frame = CGRect(x: 0 , y: KScreenHeight - ALScanViewY, width:KScreenWidth, height: ALScanViewY)
            self.scanBgView?.addSubview(bottomView)
            
            let scanView = UIImageView.init(image: UIImage.init(named: "ticket_scan_border"))
            scanView.backgroundColor = UIColor.clear
            scanView.frame = scanRect()
            self.scanBgView?.addSubview(scanView)
            
            let noteButton = UIButton()
            noteButton.setTitle("将二维码放入框内", for: .normal)
            noteButton.layer.borderColor = UIColor.lightGray.cgColor
            noteButton.layer.borderWidth = 0.5
            noteButton.layer.cornerRadius = 12.5
            noteButton.clipsToBounds = true
            noteButton.titleLabel?.textAlignment = .center
            noteButton.titleLabel?.font = UIFont.systemFont(ofSize: 12)
            self.scanBgView?.addSubview(noteButton)
            noteButton.frame = CGRect(x: (KScreenWidth - 126)/2, y: scanView.frame.maxY + 25, width: 126, height: 26)
            
            
            if flashlight == nil {
                flashlight = UIButton()
                self.view.addSubview(flashlight)
                flashlight.setImage(UIImage.init(named: "ticket_scan_flashlight_off"), for: .normal)
                flashlight.setImage(UIImage.init(named: "ticket_scan_flashlight_on"), for: .selected)
                flashlight.setTitleColor(UIColor.white, for: .normal)
                flashlight.setTitleColor(UIColor.blue, for: .selected)
                flashlight.setTitle("轻点照亮", for: .normal)
                flashlight.imageView?.contentMode = .scaleAspectFill
                flashlight.titleLabel?.font = UIFont.systemFont(ofSize: 12)
                flashlight.imageEdgeInsets = UIEdgeInsetsMake(-20-8/2, 0, 0, -58)
                flashlight.titleEdgeInsets = UIEdgeInsetsMake(46 + 8/2, (-16), 0, 0)
                flashlight.isSelected = false
                flashlight.addTarget(self, action: #selector(flashlightAction), for: .touchUpInside)
                flashlight.frame = CGRect(x: (KScreenWidth - 58)/2 , y: noteButton.frame.maxY + 10 , width: 58, height: 74)
                
            }
            self.scanLineView = UIImageView.init(image: UIImage.init(named: "ticket_scan_line"))
            self.scanLineView?.frame = CGRect(x: ALScanViewX + ALScanLineLeftAndRightMargin, y: ALScanViewY + 6 , width: ALScanWidth - ALScanLineLeftAndRightMargin*2, height: ALScanLineHeight)
            self.scanBgView?.addSubview(self.scanLineView!)
        }
        if self.timer == nil {
            timer = DispatchSource.makeTimerSource(flags: [], queue: DispatchQueue.main)
            timer.schedule(deadline: .now(), repeating: 0.01)
            timer.setEventHandler {
                DispatchQueue.main.async {
                    if (self.scanLineView?.frame.origin.y)! + 1 > (KScreenHeight - ALScanViewY - ALScanLineHeight - 6*2){
                        self.scanLineView?.frame.origin.y = ALScanViewY + 6
                    }else{
                        self.scanLineView?.frame.origin.y += 1
                    }
                }
            }
        }
        self.timer.resume()
        
        self.view.addSubview(self.scanBgView!)
        self.view.sendSubview(toBack: self.scanBgView!)
    }

打开闪光灯

// MARK: 手电筒开启关闭
    @objc func flashlightAction(){
        if (self.scanDevice?.hasTorch)! && (self.scanDevice?.isTorchAvailable)! {
            // 注意在开启关闭闪光灯的时候要注意先要锁定设备
            try? self.scanDevice?.lockForConfiguration()
            if self.scanDevice?.torchMode == .off {
                self.scanDevice?.torchMode = .on
                self.flashlight.isSelected = true
            } else {
                self.scanDevice?.torchMode = .off
                self.flashlight.isSelected = false
            }
            // 在设置完设备属性后要记得解锁设备
            self.scanDevice?.unlockForConfiguration()
        }
    }