Swift中自动生成中间带小头像的二维码

//MARK: -传进去字符串,生成二维码图片

private func creatQRCodeImage(text: String, sizeH:CGFloat) -> UIImage{

//text是二维码要带入的信息，sizeH是二维码的高度

//创建滤镜

let filter = CIFilter(name: "CIQRCodeGenerator")!

//还原滤镜的默认属性

filter.setDefaults()

//设置需要生成二维码的数据

filter.setValue(text.dataUsingEncoding(NSUTF8StringEncoding), forKey: "inputMessage")

//从滤镜中取出生成的图片

let ciImage = filter.outputImage

//这个清晰度不好

//let bgImage = UIImage(CIImage: ciImage!)

//这个清晰度好

let bgImage = createNonInterpolatedUIImageFormCIImage(ciImage!, size: sizeH)

//创建一个头像

let icon = UIImage(named: "icon")

//合成图片(把二维码和头像合并)

let newImage = creatImage(bgImage, iconImage: icon!)

//返回生成好的二维码

return newImage

}

//MARK: - 根据背景图片和头像合成头像二维码, 即是中间带头像的二维码

private func creatImage(bgImage: UIImage, iconImage:UIImage) -> UIImage{

//开启图片上下文

UIGraphicsBeginImageContext(bgImage.size)

//绘制背景图片

bgImage.drawInRect(CGRect(origin: CGPointZero, size: bgImage.size))

//绘制头像

let width: CGFloat = 50

let height: CGFloat = width

let x = (bgImage.size.width - width) * 0.5

let y = (bgImage.size.height - height) * 0.5

iconImage.drawInRect(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

return newImage

}

//MARK: - 根据CIImage生成指定大小的高清UIImage

private func createNonInterpolatedUIImageFormCIImage(image: CIImage, size: CGFloat) -> UIImage {

let extent: CGRect = CGRectIntegral(image.extent)

let scale: CGFloat = min(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent))

let width = CGRectGetWidth(extent) * scale

let height = CGRectGetHeight(extent) * scale

let cs: CGColorSpaceRef = CGColorSpaceCreateDeviceGray()!

let bitmapRef = CGBitmapContextCreate(nil, Int(width), Int(height), 8, 0, cs, 0)!

let context = CIContext(options: nil)

let bitmapImage: CGImageRef = context.createCGImage(image, fromRect: extent)

CGContextSetInterpolationQuality(bitmapRef,  CGInterpolationQuality.None)

CGContextScaleCTM(bitmapRef, scale, scale);

CGContextDrawImage(bitmapRef, extent, bitmapImage);

let scaledImage: CGImageRef = CGBitmapContextCreateImage(bitmapRef)!

return UIImage(CGImage: scaledImage)

}