生成二维码（中间带图片）

引用：https://www.jianshu.com/p/357c6477edf2

使用：

        qrCodeImageView = UIImageView.init(frame: CGRect.init(x: 0, y: 100, width: 200, height: 200))
        qrCodeImageView.backgroundColor = UIColor.green
        view.addSubview(qrCodeImageView)
    
        qrCodeImageView.image = CreateQrcodeTool.shared.setupQRCodeImage("https://www.jianshu.com/u/01b7a2dd26e8", image: UIImage.init(named: ""))

实现：

class CreateQrcodeTool  : NSObject {

    static let shared: CreateQrcodeTool = {
        let timer = CreateQrcodeTool()
        return timer
    }()
    
    //MARK: -传进去字符串,生成二维码图片
     func setupQRCodeImage(_ text: String, image: UIImage?) -> UIImage {
        //创建滤镜
        let filter = CIFilter(name: "CIQRCodeGenerator")
        filter?.setDefaults()
        //将url加入二维码
        filter?.setValue(text.data(using: String.Encoding.utf8), forKey: "inputMessage")
        //取出生成的二维码（不清晰）
        if let outputImage = filter?.outputImage {
            //生成清晰度更好的二维码
            let qrCodeImage = setupHighDefinitionUIImage(outputImage, size: 300)
            //如果有一个头像的话，将头像加入二维码中心
            if var image = image {
                //给头像加一个白色圆边（如果没有这个需求直接忽略）
                image = circleImageWithImage(image, borderWidth: 50, borderColor: UIColor.white)
                //合成图片
                let newImage = syntheticImage(qrCodeImage, iconImage: image, width: 100, height: 100)
                
                return newImage
            }
            
            return qrCodeImage
        }
        
        return UIImage()
    }
    
    //image: 二维码 iconImage:头像图片 width: 头像的宽 height: 头像的宽
    private func syntheticImage(_ image: UIImage, iconImage:UIImage, width: CGFloat, height: CGFloat) -> UIImage{
        //开启图片上下文
        UIGraphicsBeginImageContext(image.size)
        //绘制背景图片
        image.draw(in: CGRect(origin: CGPoint.zero, size: image.size))
        
        let x = (image.size.width - width) * 0.5
        let y = (image.size.height - height) * 0.5
        iconImage.draw(in: CGRect(x: x, y: y, width: width, height: height))
        //取出绘制好的图片
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        //关闭上下文
        UIGraphicsEndImageContext()
        //返回合成好的图片
        if let newImage = newImage {
            return newImage
        }
        return UIImage()
    }
    
    //MARK: - 生成高清的UIImage
    private func setupHighDefinitionUIImage(_ image: CIImage, size: CGFloat) -> UIImage {
        let integral: CGRect = image.extent.integral
        let proportion: CGFloat = min(size/integral.width, size/integral.height)
        
        let width = integral.width * proportion
        let height = integral.height * proportion
        let colorSpace: CGColorSpace = CGColorSpaceCreateDeviceGray()
        let bitmapRef = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: 0)!
        
        let context = CIContext(options: nil)
        let bitmapImage: CGImage = context.createCGImage(image, from: integral)!
        
        bitmapRef.interpolationQuality = CGInterpolationQuality.none
        bitmapRef.scaleBy(x: proportion, y: proportion);
        bitmapRef.draw(bitmapImage, in: integral);
        let image: CGImage = bitmapRef.makeImage()!
        return UIImage(cgImage: image)
    }
    
    //生成边框
    func circleImageWithImage(_ sourceImage: UIImage, borderWidth: CGFloat, borderColor: UIColor) -> UIImage {
        let imageWidth = sourceImage.size.width + 2 * borderWidth
        let imageHeight = sourceImage.size.height + 2 * borderWidth
        
        UIGraphicsBeginImageContextWithOptions(CGSize(width: imageWidth, height: imageHeight), false, 0.0)
        UIGraphicsGetCurrentContext()
        
        let radius = (sourceImage.size.width < sourceImage.size.height ? sourceImage.size.width:sourceImage.size.height) * 0.5
        let bezierPath = UIBezierPath(arcCenter: CGPoint(x: imageWidth * 0.5, y: imageHeight * 0.5), radius: radius, startAngle: 0, endAngle: .pi * 2, clockwise: true)
        bezierPath.lineWidth = borderWidth
        borderColor.setStroke()
        bezierPath.stroke()
        bezierPath.addClip()
        sourceImage.draw(in: CGRect(x: borderWidth, y: borderWidth, width: sourceImage.size.width, height: sourceImage.size.height))
        
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        return image!
    }
}

效果：

image.png