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我能够成功扫描全相机分辨率条形码内，但我想它应该只在特定的帧（盒被置于中心）扫描条形码。如果条码在于该框架之外不应该进行扫描。
var session : AVCaptureSession = AVCaptureSession()
var previewLayer : AVCaptureVideoPreviewLayer!
var highlightView : UIView = UIView()
func opencamera()
{
if session.running
{
}
else
{
session = AVCaptureSession()
// Set the captureDevice.
let videoCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
session.sessionPreset = AVCaptureSessionPresetInputPriority
// Create input object.
let videoInput: AVCaptureDeviceInput?
do {
videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
} catch {
return
}
// Add input to the session.
if (session.canAddInput(videoInput)) {
session.addInput(videoInput)
} else {
scanningNotPossible()
}
let metadataOutput = AVCaptureMetadataOutput()
// Add output to the session.
if (session.canAddOutput(metadataOutput)) {
session.addOutput(metadataOutput)
// Send captured data to the delegate object via a serial queue.
metadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
// Set barcode type for which to scan: EAN-13.
//metadataOutput.metadataObjectTypes = metadataOutput.availableMetadataObjectTypes
metadataOutput.metadataObjectTypes = [AVMetadataObjectTypeUPCECode,
AVMetadataObjectTypeCode39Code,
AVMetadataObjectTypeCode39Mod43Code,
AVMetadataObjectTypeEAN13Code,
AVMetadataObjectTypeEAN8Code,
AVMetadataObjectTypeCode93Code,
AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypePDF417Code,
]
} else {
scanningNotPossible()
}
previewLayer = AVCaptureVideoPreviewLayer(session: session);
previewLayer.frame = self.view.frame
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer?.position = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds))
image.layer.addSublayer(previewLayer);
session.startRunning()
}
}
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {
//var highlightViewRect = CGRectZero
// var barCodeObject : AVMetadataObject!
var detectionString : String!
let barCodeTypes = [AVMetadataObjectTypeUPCECode,
AVMetadataObjectTypeCode39Code,
AVMetadataObjectTypeCode39Mod43Code,
AVMetadataObjectTypeEAN13Code,
AVMetadataObjectTypeEAN8Code,
AVMetadataObjectTypePDF417Code,
]
// The scanner is capable of capturing multiple 2-dimensional barcodes in one scan.
for metadata in metadataObjects {
for barcodeType in barCodeTypes {
let decodedData: AVMetadataMachineReadableCodeObject = metadata as! AVMetadataMachineReadableCodeObject
if metadata.type == barcodeType {
detectionString = (metadata as! AVMetadataMachineReadableCodeObject).stringValue
if(metadata.type == AVMetadataObjectTypeEAN13Code){
if (detectionString.hasPrefix("0") && detectionString.characters.count > 1){
detectionString = String(detectionString.characters.dropFirst())
}
}
AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
self.session.stopRunning()
break
}
}
}
print(detectionString)
self.previewLayer.removeFromSuperlayer()
self.highlightView.removeFromSuperview()
}