ios開發之Swift使用CIFilter產生二維碼圖片（QRCode）

CIFilter提供了各種各樣的濾鏡，其中CIQRCodeGenerator可以用來產生二維碼。下面通過一個範例示範如何將字串（連結也是字串）產生二維碼圖片，同時支援在二維碼中間放置個人化表徵圖。

 

效果圖如下：

 

代碼如下

複製代碼

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)     }           //建立二維碼圖片     func createQRForString(qrString: String?, qrImageName: String?) -> UIImage?{         if let sureQRString = qrString {             let stringData = sureQRString.dataUsingEncoding(NSUTF8StringEncoding,                 allowLossyConversion: false)             // 建立一個二維碼的濾鏡             let qrFilter = CIFilter(name: "CIQRCodeGenerator")!             qrFilter.setValue(stringData, forKey: "inputMessage")             qrFilter.setValue("H", forKey: "inputCorrectionLevel")             let qrCIImage = qrFilter.outputImage             // 建立一個顏色濾鏡,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,二維碼都是定製的,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()     } }