我使用以下代码来扫描条形码:
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,
AVMetadataObjectTypeCode93Code,
AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypePDF417Code,
AVMetadataObjectTypeQRCode,
AVMetadataObjectTypeAztecCode
]
// The scanner is capable of capturing multiple 2-dimensional barcodes in one scan.
for metadata in metadataObjects {
for barcodeType in barCodeTypes {
if metadata.type == barcodeType {
barCodeObject = self.previewLayer.transformedMetadataObjectForMetadataObject(metadata as! AVMetadataMachineReadableCodeObject)
highlightViewRect = barCodeObject.bounds
detectionString = (metadata as! AVMetadataMachineReadableCodeObject).stringValue
let len = detectionString.characters.count
print("raw=\(detectionString)")
if len == 25 {
detectionString=detectionString.substringWithRange(Range<String.Index>(start: detectionString.startIndex.advancedBy(3), end: detectionString.endIndex.advancedBy(0)))
} else if len > 22 {
detectionString=detectionString.substringWithRange(Range<String.Index>(start: detectionString.startIndex.advancedBy(22), end: detectionString.endIndex.advancedBy(0)))
}
print("mod=\(detectionString)")
}
}
}
self.session.stopRunning()
sendScan(detectionString)
self.highlightView.frame = highlightViewRect
self.view.bringSubviewToFront(self.highlightView)
}
看起来它应该从同一次扫描中捕获多个条形码。然而,它只捕获一个。我确信我在这里做错了什么,但我不确定是什么。
最佳答案
同时检测的最大数量为4,此数量仅适用于二维条码。一维条形码识别仅限于 1 次检测。有关详细信息,请参阅此引用:
运行您的代码(就所提供的而言),让我获得多个(2D)检测。请注意,sendScan 方法仅发送最后检测到的项目。
对您的代码进行轻微修改:
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {
var captures : [String] = []
for metadata in metadataObjects {
var detectionString = (metadata as! AVMetadataMachineReadableCodeObject).stringValue
let len = detectionString.characters.count
print("raw=\(detectionString)")
if len == 25 {
detectionString = detectionString.substringWithRange(Range<String.Index>(start: detectionString.startIndex.advancedBy(3), end: detectionString.endIndex.advancedBy(0)))
} else if len > 22 {
detectionString = detectionString.substringWithRange(Range<String.Index>(start: detectionString.startIndex.advancedBy(22), end: detectionString.endIndex.advancedBy(0)))
}
print("mod=\(detectionString)")
captures.append(detectionString)
}
print("Captured \(captures.count) barcodes.")
}
产生此输出:
raw=www.barcode1.co.za
mod=www.barcode1.co.za
raw=http://www.moxx.in
mod=http://www.moxx.in
raw=http://www.harrowhouse.com/
mod=.com/
raw=Ver1
mod=Ver1
Captured 4 barcodes.
关于iOS Swift 扫描多个条形码,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34404015/