QRCode不但可以使用在pc中的一些程序調用生成二維碼同時也支持在手機中直接調用開發，下面來看一個Swift使用CIFilter生成二維碼圖片的例子。

CIFilter提供了各種各樣的濾鏡，其中CIQRCodeGenerator可以用來生成二維碼。下面通過一個樣例演示如何將字符串（鏈接也是字符串）生成二維碼圖片，同時支持在二維碼中間放置個性化圖標。

  效果圖如下：

 

 代碼如下 復制代碼 import UIKit
 
class ViewController: UIViewController {
 
    override func viewDidLoad() {
        super.viewDidLoad()
         
        //不帶圖片的二維碼圖片
        let imageViewIcon1 = UIImageView(frame: CGRectMake(20, 20, 150, 150))
        imageViewIcon1.image = createQRForString("http://www.111cn.net",
            qrImageName: "")
        self.view.addSubview(imageViewIcon1)
         
        //帶圖片的二維碼圖片
        let imageViewIcon2 = UIImageView(frame: CGRectMake(200, 20, 150, 150))
        imageViewIcon2.image = createQRForString("http://www.111cn.net",
            qrImageName: "logo")
        self.view.addSubview(imageViewIcon2)
    }
     
    //創建二維碼圖片
    func createQRForString(qrString: String?, qrImageName: String?) -> UIImage?{
        if let sureQRString = qrString {
            let stringData = sureQRString.dataUsingEncoding(NSUTF8StringEncoding,
                allowLossyConversion: false)
            // 創建一個二維碼的濾鏡
            let qrFilter = CIFilter(name: "CIQRCodeGenerator")!
            qrFilter.setValue(stringData, forKey: "inputMessage")
            qrFilter.setValue("H", forKey: "inputCorrectionLevel")
            let qrCIImage = qrFilter.outputImage
            // 創建一個顏色濾鏡,黑白色
            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")
            // 返回二維碼image
            let codeImage = UIImage(CIImage: colorFilter.outputImage!
                .imageByApplyingTransform(CGAffineTransformMakeScale(5, 5)))
            // 通常,二維碼都是定制的,中間都會放想要表達意思的圖片
            if let iconImage = UIImage(named: qrImageName!) {
                let rect = CGRectMake(0, 0, codeImage.size.width, codeImage.size.height)
                UIGraphicsBeginImageContext(rect.size)
                 
                codeImage.drawInRect(rect)
                let avatarSize = CGSizeMake(rect.size.width * 0.25, rect.size.height * 0.25)
                let x = (rect.width - avatarSize.width) * 0.5
                let y = (rect.height - avatarSize.height) * 0.5
                iconImage.drawInRect(CGRectMake(x, y, avatarSize.width, avatarSize.height))
                let resultImage = UIGraphicsGetImageFromCurrentImageContext()
                 
                UIGraphicsEndImageContext()
                return resultImage
            }
            return codeImage
        }
        return nil
    }
 
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}