我是一名新的 iOS 开发者。我想知道如何在 Swift 中生成条形码。
我已经有了代码,有多种资源可以学习如何读取条形码,但我没有找到任何关于从字符串生成条形码的资源。
非常感谢!
附注我知道有一个类似的问题,但它是针对 Objective-C 的。我不了解 Obj-C,而且我发现来自 .NET 很难。
您可以使用 CoreImage (
import CoreImage
) 过滤器来做到这一点!
class Barcode {
class func fromString(string : String) -> UIImage? {
let data = string.data(using: .ascii)
if let filter = CIFilter(name: "CICode128BarcodeGenerator") {
filter.setValue(data, forKey: "inputMessage")
if let outputCIImage = filter.outputImage {
return UIImage(ciImage: outputCIImage)
}
}
return nil
}
}
let img = Barcode.fromString("whateva")
较新的版本,带有
guard
和可失败的初始化程序:
extension UIImage {
convenience init?(barcode: String) {
let data = barcode.data(using: .ascii)
guard let filter = CIFilter(name: "CICode128BarcodeGenerator") else {
return nil
}
filter.setValue(data, forKey: "inputMessage")
guard let ciImage = filter.outputImage else {
return nil
}
self.init(ciImage: ciImage)
}
}
用途:
let barcode = UIImage(barcode: "some text") // yields UIImage?
根据文档:
根据输入数据生成代表输入数据的输出图像 ISO/IEC 15417:2007 标准。每个模块的宽度(垂直线) 输出图像中条形码的宽度为一个像素。的高度 条形码是 32 像素。要从字符串或 URL 创建条形码, 使用 NSASCIIStringEncoding 字符串将其转换为 NSData 对象 编码。
改进的代码:
斯威夫特3
func generateBarcode(from string: String) -> UIImage? {
let data = string.data(using: String.Encoding.ascii)
if let filter = CIFilter(name: "CICode128BarcodeGenerator") {
filter.setDefaults()
//Margin
filter.setValue(7.00, forKey: "inputQuietSpace")
filter.setValue(data, forKey: "inputMessage")
//Scaling
let transform = CGAffineTransform(scaleX: 3, y: 3)
if let output = filter.outputImage?.applying(transform) {
let context:CIContext = CIContext.init(options: nil)
let cgImage:CGImage = context.createCGImage(output, from: output.extent)!
let rawImage:UIImage = UIImage.init(cgImage: cgImage)
//Refinement code to allow conversion to NSData or share UIImage. Code here:
//http://stackoverflow.com/questions/2240395/uiimage-created-from-cgimageref-fails-with-uiimagepngrepresentation
let cgimage: CGImage = (rawImage.cgImage)!
let cropZone = CGRect(x: 0, y: 0, width: Int(rawImage.size.width), height: Int(rawImage.size.height))
let cWidth: size_t = size_t(cropZone.size.width)
let cHeight: size_t = size_t(cropZone.size.height)
let bitsPerComponent: size_t = cgimage.bitsPerComponent
//THE OPERATIONS ORDER COULD BE FLIPPED, ALTHOUGH, IT DOESN'T AFFECT THE RESULT
let bytesPerRow = (cgimage.bytesPerRow) / (cgimage.width * cWidth)
let context2: CGContext = CGContext(data: nil, width: cWidth, height: cHeight, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: CGColorSpaceCreateDeviceRGB(), bitmapInfo: cgimage.bitmapInfo.rawValue)!
context2.draw(cgimage, in: cropZone)
let result: CGImage = context2.makeImage()!
let finalImage = UIImage(cgImage: result)
return finalImage
}
}
return nil
}
如果您的部署目标至少是 iOS 8,则可以使用 Core Image。这是我的 BarcodeGenerator 类(您需要
import CoreImage
):
class BarcodeGenerator {
enum Descriptor: String {
case code128 = "CICode128BarcodeGenerator"
case pdf417 = "CIPDF417BarcodeGenerator"
case aztec = "CIAztecCodeGenerator"
case qr = "CIQRCodeGenerator"
}
class func generate(from string: String,
descriptor: Descriptor,
size: CGSize) -> CIImage? {
let filterName = descriptor.rawValue
guard let data = string.data(using: .ascii),
let filter = CIFilter(name: filterName) else {
return nil
}
filter.setValue(data, forKey: "inputMessage")
guard let image = filter.outputImage else {
return nil
}
let imageSize = image.extent.size
let transform = CGAffineTransform(scaleX: size.width / imageSize.width,
y: size.height / imageSize.height)
let scaledImage = image.transformed(by: transform)
return scaledImage
}
}
可以这样使用
BarcodeGenerator.generate(from: "barcode-string",
descriptor: .code128,
size: CGSize(width: 800, height: 300))
这样使用,
func createBarcodeFromString(barcode:String)->UIImage?{
let data = self.data(using: .isoLatin1)
guard let filter = CIFilter(name: "CICode128BarcodeGenerator") else {
return nil
}
filter.setValue(data, forKey: "inputMessage")
filter.setValue(7.0, forKey:"inputQuietSpace")
guard var ciImage = filter.outputImage else {
return nil
}
let imageSize = ciImage.extent.integral
let outputSize = CGSize(width:320, height: 60)
ciImage = ciImage.transformed(by:CGAffineTransform(scaleX: outputSize.width/imageSize.width, y: outputSize.height/imageSize.height))
let image = convertCIImageToUIImage(ciimage: ciImage)
return image
}
func convertCIImageToUIImage(ciimage:CIImage)->UIImage{
let context:CIContext = CIContext.init(options: nil)
let cgImage:CGImage = context.createCGImage(ciimage, from: ciimage.extent)!
let image:UIImage = UIImage.init(cgImage: cgImage)
return image
}
与 Matteo Pacini 的 答案类似,这是使用较新的类型安全
CIFilter
实例(iOS 13.0+)的版本。
import UIKit
import CoreImage.CIFilterBuiltins // Type-safe CIFilter instances, iOS 13.0+
extension UIImage {
static func barcode(
string: String,
height: Float,
quietSpace: Float
) -> UIImage? {
guard let message = string.data(using: String.Encoding.ascii) else {
return nil
}
let filter = CIFilter.code128BarcodeGenerator()
filter.message = message
filter.barcodeHeight = height
filter.quietSpace = quietSpace
guard let outputImage = filter.outputImage else {
return nil
}
return UIImage(ciImage: outputImage)
}
}
用途:
imageView.image = .barcode(
string: "0123456789",
height: 64,
quietSpace: 10
)
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