使用Swift语言生成二维码

 1 import UIKit
 2 
 3 class QRCodeCreateViewController: UIViewController {
 4 
 5     @IBOutlet weak var iconImage: UIImageView!
 6     
 7     override func viewDidLoad() {
 8         super.viewDidLoad()
 9 
10         createQRCode()
11     }
12 
13     private func createQRCode() {
14         
15         // 建立一个滤镜
16         let qrFilter = CIFilter(name: "CIQRCodeGenerator")
17         // 重设滤镜的初始值
18         qrFilter.setDefaults()
19         
20         // 通过 KVC 设置滤镜的内容
21         qrFilter.setValue("我的第一个二维码".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true), forKey: "inputMessage")
22         
23         // 输出图像
24         let ciImage = qrFilter.outputImage
25         // 打印生成图片的大小，生成的图像 23 * 23
26         println(ciImage.extent())
27         
28         // 过滤图像单色彩以及`形变`的滤镜
29         let colorFilter = CIFilter(name: "CIFalseColor")
30         colorFilter.setDefaults()
31         
32         colorFilter.setValue(ciImage, forKey: "inputImage")
33         
34         // 不能直接用 UIColor 转换，会崩溃
35 //        colorFilter.setValue(UIColor.redColor().CIColor, forKey: "inputColor0")
36         // 前景色
37         colorFilter.setValue(CIColor(red: 0, green: 0, blue: 0), forKey: "inputColor0")
38         // 背景色
39         colorFilter.setValue(CIColor(red: 1, green: 1, blue: 1), forKey: "inputColor1")
40         
41         let transform = CGAffineTransformMakeScale(5, 5)
42         let transformImage = colorFilter.outputImage.imageByApplyingTransform(transform)
43         
44         let codeImage = UIImage(CIImage: transformImage)
45         let avatarImage = UIImage(named: "avatar")
46         
47         iconImage.image = insertAvatarImage(codeImage!, avatarImage: avatarImage!)
48     }
49 
50     // 合成头像图像
51     private func insertAvatarImage(codeImage: UIImage, avatarImage: UIImage) -> UIImage {
52         
53         let size = codeImage.size
54         
55         // 1. 开启图像的上下文
56         UIGraphicsBeginImageContext(size)
57         
58         // 2. 绘制二维码图像
59         codeImage.drawInRect(CGRectMake(0, 0, size.width, size.height))
60         
61         // 3. 计算头像的大小
62         let w = size.width * 0.25
63         let h = size.height * 0.25
64         let x = (size.width - w) * 0.5
65         let y = (size.height - h) * 0.5
66         
67         avatarImage.drawInRect(CGRectMake(x, y, w, h))
68         
69         // 4. 从上下文中取出图像
70         let image = UIGraphicsGetImageFromCurrentImageContext()
71         
72         // 5. 关闭上下文
73         UIGraphicsEndImageContext()
74 
75         return image
76     }