iOS快速条形码读取
我的应用程序中正在进行条形码扫描。检测到条形码后，我停止捕获会话以允许处理条形码。但是，在处理完条形码后，我希望扫描控制器保持不动，并扫描下一个条形码。我假设启动捕获会话（startRunning（））就可以了，但是图像保持冻结状态。如何再次启动捕获会话？要停止会话，请使用以下代码iOS快速条形码读取,ios,swift,barcode,Ios,Swift,Barcode,我的应用程序中正在进行条形码扫描。检测到条形码后，我停止捕获会话以允许处理条形码。但是，在处理完条形码后，我希望扫描控制器保持不动，并扫描下一个条形码。我假设启动捕获会话（startRunning（））就可以了，但是图像保持冻结状态。如何再次启动捕获会话？要停止会话，请使用以下代码 self.session.stopRunning() self.session.startRunning() 要重新开始，请使用以下代码 self.session.stopRunning() self.sess
self.session.stopRunning()
self.session.startRunning()
self.session.stopRunning()
self.session.startRunning()
import UIKit
import AVFoundation
class ViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
let session : AVCaptureSession = AVCaptureSession()
var previewLayer : AVCaptureVideoPreviewLayer!
var highlightView : UIView = UIView()
override func viewDidLoad() {
super.viewDidLoad()
// Allow the view to resize freely
self.highlightView.autoresizingMask =
UIViewAutoresizing.FlexibleTopMargin |
UIViewAutoresizing.FlexibleBottomMargin |
UIViewAutoresizing.FlexibleLeftMargin |
UIViewAutoresizing.FlexibleRightMargin
// Select the color you want for the completed scan reticle
self.highlightView.layer.borderColor = UIColor.greenColor().CGColor
self.highlightView.layer.borderWidth = 3
// Add it to our controller's view as a subview.
self.view.addSubview(self.highlightView)
// For the sake of discussion this is the camera
let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// Create a nilable NSError to hand off to the next method.
// Make sure to use the "var" keyword and not "let"
var error : NSError? = nil
let input : AVCaptureDeviceInput? =
AVCaptureDeviceInput.deviceInputWithDevice(device, error: &error)
as? AVCaptureDeviceInput
// If our input is not nil then add it to the session, otherwise we're kind of done!
if input != nil {
session.addInput(input)
} else {
// This is fine for a demo, do something real with this in your app. :)
println(error)
}
let output = AVCaptureMetadataOutput()
output.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
session.addOutput(output)
output.metadataObjectTypes = output.availableMetadataObjectTypes
previewLayer =
AVCaptureVideoPreviewLayer.layerWithSession(session)
as! AVCaptureVideoPreviewLayer
previewLayer.frame = self.view.bounds
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
self.view.layer.addSublayer(previewLayer)
// Start the scanner. You'll have to end it yourself later.
session.startRunning()
}
// This is called when we find a known barcode type with the camera.
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
self.session.stopRunning()
self.alert(detectionString)
break
}
}
}
println(detectionString)
self.highlightView.frame = highlightViewRect
self.view.bringSubviewToFront(self.highlightView)
}
func alert(Code: String){
let actionSheet:UIAlertController =
UIAlertController(
title: "Barcode",
message: "\(Code)",
preferredStyle: UIAlertControllerStyle.Alert)
// for alert add .Alert instead of .Action Sheet
// start copy
let firstAlertAction:UIAlertAction =
UIAlertAction(
title: "OK",
style: UIAlertActionStyle.Default,
handler: { (alertAction: UIAlertAction!) in
// action when pressed
self.session.startRunning()
})
actionSheet.addAction(firstAlertAction)
// end copy
self.presentViewController(actionSheet, animated: true, completion: nil)
}
}
编辑了swift 2.0的上述代码：
导入UIKit
进口AVF基金会
类BarCodeViewController:UIViewController、AVCaptureMataOutputObjectsDelegate{
let session:AVCaptureSession=AVCaptureSession（）
var previewLayer:AVCaptureVideoPreviewLayer！
@IBVAR highlightView:UIView！
重写func viewDidLoad（）{
super.viewDidLoad（）
//为完成的扫描十字线选择所需的颜色
self.highlightView.layer.borderColor=UIColor.greenColor（）.CGColor
self.highlightView.layer.borderWidth=3
//将其作为子视图添加到控制器的视图中。
self.view.addSubview（self.highlightView）
//为了便于讨论，这是相机
let device=AVCaptureDevice.defaultDeviceWithMediaType（AVMediaTypeVideo）
//创建一个可为零的NSError以切换到下一个方法。
//确保使用“var”关键字，而不是“let”
变量错误：n错误？=nil
变量输入：AVCaptureDeviceInput=AVCaptureDeviceInput（）
做{
输入=尝试将AVCaptureDeviceInput（设备：设备）作为AVCaptureDeviceInput
}让我来抓你{
打印（myJSONError）
}
//如果我们的输入不是零，那么将其添加到会话中，否则我们就完成了！
如果输入！=AVCaptureDeviceInput（）{
会话.添加输入（输入）
}
否则{
//这对于演示来说很好，在你的应用程序中使用它做一些真实的事情。：）
打印（错误）
}
let output=avcaptureMataOutput（）
setMetadataObjectsDelegate（self，queue:dispatch\u get\u main\u queue（））
session.addOutput（输出）
output.metadataObjectTypes=output.availableMetadataObjectTypes
previewLayer=AVCaptureVideoPreviewLayer（会话：会话）
previewLayer.frame=self.view.bounds
previewLayer.videoGravity=AVLayerVideoGravityResizeAspectFill
self.view.layer.addSublayer（预览层）
//启动扫描器。你以后必须自己结束它。
会议.启动耳轴（）
}
//当我们在相机中找到已知的条形码类型时，就会调用此函数。
func captureOutput（captureOutput:AVCaptureOutput！，didOutputMetadataObjects metadataObjects:[AnyObject]！，fromConnection连接：AVCaptureConnection！）{
var highlightViewRect=CGRectZero
var barCodeObject:AVMetadataObject！
变量检测字符串：字符串！
让barCodeTypes=[AVMetadataObjectTypeUPCECode，
AVMetadataObjectTypeCode39Code，
AVMetadataObjectTypeCode39Mod43Code，
AVMetadataObjectTypeAn13Code，
AVMetadataObjectTypeAna8Code，
AVMetadataObjectTypeCode93Code，
AVMetadataObjectTypeCode128Code，
AVMetadataObjectTypePDF417代码，
AVMetadataObjectTypeQRCode，
AVMetadataObjectTypeAztecCode
]
//扫描仪能够在一次扫描中捕获多个二维条形码。
用于元数据对象中的元数据{
对于barCodeTypes中的barcodeType{
如果metadata.type==barcodeType{
barCodeObject=self.previewLayer.TransformedMetadataObjectFormMetadataObject（元数据为！AVMetadataMachineReadableCodeObject）
highlightViewRect=barCodeObject.bounds
detectionString=（元数据为！avMetadataMachineAdableCodeObject）。stringValue
self.session.stopRunning（）
自我警报（检测字符串）
打破
}
}
}
打印（检测字符串）
self.highlightView.frame=highlightView-rect
self.view.bringsubview到前面（self.highlightView）
}
func警报（代码：字符串）{
let actionSheet:UIAlertController=UIAlertController（标题：“条形码”，消息：“\（代码）”，首选样式：UIAlertControllerStyle.Alert）
//对于警报，添加.alert而不是.Action表
//开始复制
让firstAlertAction:UIAlertAction=UIAlertAction（标题：“确定”，样式：UIAlertActionStyle.Default，处理程序：{
（alertAction:UIAlertAction！）在中
//按下时的动作
self.session.startRunning（）
})
actionSheet.addAction（firstAlertAction）
//结束副本
self.presentViewController（操作表，动画：true，完成：nil）
}
}
import UIKit
import AVFoundation
class BarCodeViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
let session : AVCaptureSession = AVCaptureSession()
var previewLayer : AVCaptureVideoPreviewLayer!
@IBOutlet weak var highlightView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
self.highlightView.layer.borderColor = UIColor.green.cgColor
self.highlightView.layer.borderWidth = 3
// Add it to our controller's view as a subview.
self.view.addSubview(self.highlightView)
// For the sake of discussion this is the camera
let device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
// Create a nilable NSError to hand off to the next method.
// Make sure to use the "var" keyword and not "let"
var error : NSError? = nil
var input: AVCaptureDeviceInput = AVCaptureDeviceInput()
do {
input = try AVCaptureDeviceInput(device: device) as AVCaptureDeviceInput
} catch let myJSONError {
print(myJSONError)
}
// If our input is not nil then add it to the session, otherwise we're kind of done!
if input != AVCaptureDeviceInput() {
session.addInput(input)
}
else {
// This is fine for a demo, do something real with this in your app. :)
print(error!)
}
let output = AVCaptureMetadataOutput()
output.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
session.addOutput(output)
output.metadataObjectTypes = output.availableMetadataObjectTypes
previewLayer = AVCaptureVideoPreviewLayer(session: session)
previewLayer.frame = self.view.bounds
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
self.view.layer.addSublayer(previewLayer)
// Start the scanner. You'll have to end it yourself later.
session.startRunning()
}
// This is called when we find a known barcode type with the camera.
@nonobjc func captureOutput(
captureOutput: AVCaptureOutput!,
didOutputMetadataObjects metadataObjects: [AnyObject]!,
fromConnection connection: AVCaptureConnection!) {
var highlightViewRect = CGRect()
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.transformedMetadataObject(for: metadata as! AVMetadataMachineReadableCodeObject)
highlightViewRect = barCodeObject.bounds
detectionString = (metadata as! AVMetadataMachineReadableCodeObject).stringValue
self.session.stopRunning()
self.alert(Code: detectionString)
break
}
}
}
print(detectionString)
self.highlightView.frame = highlightViewRect
self.view.bringSubview(toFront: self.highlightView)
}
func alert(Code: String){
let actionSheet:UIAlertController = UIAlertController(title: "Barcode", message: "\(Code)", preferredStyle: UIAlertControllerStyle.alert)
// for alert add .Alert instead of .Action Sheet
// start copy
let firstAlertAction:UIAlertAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: { (alertAction: UIAlertAction!) in
// action when pressed
self.session.startRunning()
})
actionSheet.addAction(firstAlertAction)
// end copy
self.present(actionSheet, animated: true, completion: nil)
}
}
Swift 5更新
func captureOutput(
captureOutput: AVCaptureOutput,
didOutputMetadataObjects metadataObjects: [AnyObject],
fromConnection connection: AVCaptureConnection,
barCodeType: [AVMetadataObject.ObjectType]) -> String? {
var detectionString: String?
var highlightViewRect = CGRect()
let barCodeTypes = barCodeType
if let metadataObject = metadataObjects.first {
for barcodeType in barCodeTypes {
if metadataObject.type == barcodeType {
guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else { return String()}
guard let barCodeObject = self.previewLayer.transformedMetadataObject(for: readableObject) else { return String()}
highlightViewRect = barCodeObject.bounds
detectionString = readableObject.stringValue
self.captureSession.stopRunning()
break
}
}
}
self.qrView.frame = highlightViewRect
self.view.bringSubviewToFront(self.qrView)
return detectionString
}
如果成功了，别忘了把这个答案标记为正确的。我做了几乎相同的事情，但我交换了两行代码。我将结果字符串发送给我的处理程序，然后停止会话。它不会重新启动。如果我在将结果发送给我的处理程序之前停止了会话，那么它就工作了+