swift小技巧之生成二维码

• 生成二维码

  func tapAction() {
      /// CIFilter
      let filter = CIFilter.init(name: "CIQRCodeGenerator")
      filter?.setDefaults()
      /// Add Data
      let data = "https://www.baidu.com".data(using: .utf8)
      filter?.setValue(data, forKeyPath: "inputMessage")
      /// Out Put
      let outputImage = filter?.outputImage
      /// Show QRCode
      self.imageView.image = createUIImageFromCIImage(image: outputImage!, size: 200)
   }

• 高清处理


  func createUIImageFromCIImage(image: CIImage, size: CGFloat) -> UIImage {
      let extent = image.extent.integral
      let scale = min(size / extent.width, size / extent.height)
          
      /// Create bitmap
      let width: size_t = size_t(extent.width * scale)
      let height: size_t = size_t(extent.height * scale)
      let cs: CGColorSpace = CGColorSpaceCreateDeviceGray()
      let bitmap: CGContext = CGContext(data: nil, width: width, height: height, bitsPerComponent: 8, bytesPerRow: 0, space: cs, bitmapInfo: 1)!
          
      let context = CIContext.init()
      let bitmapImage = context.createCGImage(image, from: extent)
      bitmap.interpolationQuality = .none
      bitmap.scaleBy(x: scale, y: scale)
      bitmap.draw(bitmapImage!, in: extent)
          
      let scaledImage = bitmap.makeImage()
      return UIImage.init(cgImage: scaledImage!)
  }