swift 系统生成二维码

文章来源:http://blog.csdn.net/sbt0198/article/details/54138425

    func createQRForString(qrString:String, qrImageNamed:String? = nil) -> UIImage {
        // 将字符串转换为二进制
        let data = qrString.data(using: String.Encoding.utf8, allowLossyConversion: false)
        let filter = CIFilter(name: "CIQRCodeGenerator")!
        filter.setValue(data, forKey: "inputMessage")
        filter.setValue("H", forKey: "inputCorrectionLevel")
        let qrCIImage = filter.outputImage
        let colorFilter = CIFilter(name: "CIFalseColor")!
        colorFilter.setDefaults()
        colorFilter.setValue(qrCIImage, forKey: "inputImage")
        colorFilter.setValue(CIColor(red: 0, green: 0, blue: 0), forKey: "inputColor0")
        colorFilter.setValue(CIColor(red: 1, green: 1, blue: 1), forKey: "inputColor1")
        
        let codeImage = UIImage(ciImage: colorFilter.outputImage!.transformed(by: CGAffineTransform(scaleX: 5, y: 5)))
        
        
        //内嵌logo
        if qrImageNamed != nil {
            if let iconImage = UIImage(named: qrImageNamed!) {
                let rect = CGRect(x:0, y:0, width:codeImage.size.width, height:codeImage.size.height)
                
                UIGraphicsBeginImageContext(rect.size)
                codeImage.draw(in: rect)
                let avatarSize = CGSize(width:rect.size.width / 4, height:rect.size.height / 4)
                let x = (rect.width - avatarSize.width) / 2
                let y = (rect.height - avatarSize.height) / 2
                
                iconImage.draw(in: CGRect(x:x, y:y, width:avatarSize.width, height:avatarSize.height))
                
                let resultImage = UIGraphicsGetImageFromCurrentImageContext()
                
                UIGraphicsEndImageContext()
                return resultImage!
            }
        }
        
        return codeImage
    }