二维码生成(CIFilter生成二维码，清晰度高的二维码，自定义颜色的二维码，带logo的二维码)

效果如下：



ViewController.h

1 #import <UIKit/UIKit.h>
2 @interface ViewController : UIViewController
3 @property (strong, nonatomic) IBOutlet UIImageView *imgVQRCode;
4
5 @end

ViewController.m

1 #import "ViewController.h"
2 #import "KMQRCode.h"
3 #import "UIImage+RoundedRectImage.h"
4
5 @interface ViewController ()
6 - (void)layoutUI;
7 @end
8
9 @implementation ViewController
10
11 - (void)viewDidLoad {
12     [super viewDidLoad];
13
14     [self layoutUI];
15 }
16
17 - (void)didReceiveMemoryWarning {
18     [super didReceiveMemoryWarning];
19     // Dispose of any resources that can be recreated.
20 }
21
22 - (void)layoutUI {
23     //用于生成二维码的字符串source
24     NSString *source = @"https://github.com/KenmuHuang";
25
26     //使用iOS 7后的CIFilter对象操作，生成二维码图片imgQRCode（会拉伸图片，比较模糊，效果不佳）
27     CIImage *imgQRCode = [KMQRCode createQRCodeImage:source];
28
29     //使用核心绘图框架CG（Core Graphics）对象操作，进一步针对大小生成二维码图片imgAdaptiveQRCode（图片大小适合，清晰，效果好）
30     UIImage *imgAdaptiveQRCode = [KMQRCode resizeQRCodeImage:imgQRCode
31                                                     withSize:_imgVQRCode.frame.size.width];
32
33     //默认产生的黑白色的二维码图片；我们可以让它产生其它颜色的二维码图片，例如：蓝白色的二维码图片
34     imgAdaptiveQRCode = [KMQRCode specialColorImage:imgAdaptiveQRCode
35                                             withRed:33.0
36                                               green:114.0
37                                                blue:237.0]; //0~255
38
39     //使用核心绘图框架CG（Core Graphics）对象操作，创建带圆角效果的图片
40     UIImage *imgIcon = [UIImage createRoundedRectImage:[UIImage imageNamed:@"QRCode"]
41                                               withSize:CGSizeMake(70.0, 93.0)
42                                             withRadius:10];
43     //使用核心绘图框架CG（Core Graphics）对象操作，合并二维码图片和用于中间显示的图标图片
44     imgAdaptiveQRCode = [KMQRCode addIconToQRCodeImage:imgAdaptiveQRCode
45                                               withIcon:imgIcon
46                                           withIconSize:imgIcon.size];
47
48 //    imgAdaptiveQRCode = [KMQRCode addIconToQRCodeImage:imgAdaptiveQRCode
49 //                                              withIcon:imgIcon
50 //                                             withScale:3];
51
52     _imgVQRCode.image = imgAdaptiveQRCode;
53     //设置图片视图的圆角边框效果
54     _imgVQRCode.layer.masksToBounds = YES;
55     _imgVQRCode.layer.cornerRadius = 10.0;
56     _imgVQRCode.layer.borderColor = [UIColor lightGrayColor].CGColor;
57     _imgVQRCode.layer.borderWidth = 4.0;
58 }
59
60 @end

​UIImage+RoundedRectImage.h

1 #import <UIKit/UIKit.h>
2
3 @interface UIImage (RoundedRectImage)
4 + (UIImage *)createRoundedRectImage:(UIImage *)image withSize:(CGSize)size withRadius:(NSInteger)radius;
5
6 @end

UIImage+RoundedRectImage.m

1 #import "UIImage+RoundedRectImage.h"
2
3 @implementation UIImage (RoundedRectImage)
4
5 #pragma mark - Private Methods
6 static void addRoundedRectToPath(CGContextRef contextRef, CGRect rect, float widthOfRadius, float heightOfRadius) {
7     float fw, fh;
8     if (widthOfRadius == 0 || heightOfRadius == 0)
9     {
10         CGContextAddRect(contextRef, rect);
11         return;
12     }
13
14     CGContextSaveGState(contextRef);
15     CGContextTranslateCTM(contextRef, CGRectGetMinX(rect), CGRectGetMinY(rect));
16     CGContextScaleCTM(contextRef, widthOfRadius, heightOfRadius);
17     fw = CGRectGetWidth(rect) / widthOfRadius;
18     fh = CGRectGetHeight(rect) / heightOfRadius;
19
20     CGContextMoveToPoint(contextRef, fw, fh/2);  // Start at lower right corner
21     CGContextAddArcToPoint(contextRef, fw, fh, fw/2, fh, 1);  // Top right corner
22     CGContextAddArcToPoint(contextRef, 0, fh, 0, fh/2, 1); // Top left corner
23     CGContextAddArcToPoint(contextRef, 0, 0, fw/2, 0, 1); // Lower left corner
24     CGContextAddArcToPoint(contextRef, fw, 0, fw, fh/2, 1); // Back to lower right
25
26     CGContextClosePath(contextRef);
27     CGContextRestoreGState(contextRef);
28 }
29
30 #pragma mark - Public Methods
31 + (UIImage *)createRoundedRectImage:(UIImage *)image withSize:(CGSize)size withRadius:(NSInteger)radius {
32     int w = size.width;
33     int h = size.height;
34
35     CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
36     CGContextRef contextRef = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpaceRef, (CGBitmapInfo)kCGImageAlphaPremultipliedFirst);
37     CGRect rect = CGRectMake(0, 0, w, h);
38
39     CGContextBeginPath(contextRef);
40     addRoundedRectToPath(contextRef, rect, radius, radius);
41     CGContextClosePath(contextRef);
42     CGContextClip(contextRef);
43     CGContextDrawImage(contextRef, CGRectMake(0, 0, w, h), image.CGImage);
44     CGImageRef imageMasked = CGBitmapContextCreateImage(contextRef);
45     UIImage *img = [UIImage imageWithCGImage:imageMasked];
46
47     CGContextRelease(contextRef);
48     CGColorSpaceRelease(colorSpaceRef);
49     CGImageRelease(imageMasked);
50     return img;
51 }
52
53 @end

KMQRCode.h

1 #import <UIKit/UIKit.h>
2
3 @interface KMQRCode : NSObject
4 + (CIImage *)createQRCodeImage:(NSString *)source;
5 + (UIImage *)resizeQRCodeImage:(CIImage *)image withSize:(CGFloat)size;
6 + (UIImage *)specialColorImage:(UIImage*)image withRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue;
7 + (UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withIconSize:(CGSize)iconSize;
8 + (UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withScale:(CGFloat)scale;
9
10 @end

KMQRCode.m

1 #import "KMQRCode.h"
2
3 @implementation KMQRCode
4
5 #pragma mark - Private Methods
6 void ProviderReleaseData (void *info, const void *data, size_t size){
7     free((void*)data);
8 }
9
10 #pragma mark - Public Methods
11 + (CIImage *)createQRCodeImage:(NSString *)source {
12     NSData *data = [source dataUsingEncoding:NSUTF8StringEncoding];
13
14     CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
15     [filter setValue:data forKey:@"inputMessage"];
16     [filter setValue:@"Q" forKey:@"inputCorrectionLevel"]; //设置纠错等级越高；即识别越容易，值可设置为L(Low) |  M(Medium) | Q | H(High)
17     return filter.outputImage;
18 }
19
20 + (UIImage *)resizeQRCodeImage:(CIImage *)image withSize:(CGFloat)size {
21     CGRect extent = CGRectIntegral(image.extent);
22     CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
23     size_t width = CGRectGetWidth(extent) * scale;
24     size_t height = CGRectGetHeight(extent) * scale;
25     CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceGray();
26
27     CGContextRef contextRef = CGBitmapContextCreate(nil, width, height, 8, 0, colorSpaceRef, (CGBitmapInfo)kCGImageAlphaNone);
28     CIContext *context = [CIContext contextWithOptions:nil];
29     CGImageRef imageRef = [context createCGImage:image fromRect:extent];
30     CGContextSetInterpolationQuality(contextRef, kCGInterpolationNone);
31     CGContextScaleCTM(contextRef, scale, scale);
32     CGContextDrawImage(contextRef, extent, imageRef);
33
34     CGImageRef imageRefResized = CGBitmapContextCreateImage(contextRef);
35
36     //Release
37     CGContextRelease(contextRef);
38     CGImageRelease(imageRef);
39     return [UIImage imageWithCGImage:imageRefResized];
40 }
41
42 + (UIImage *)specialColorImage:(UIImage*)image withRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue {
43     const int imageWidth = image.size.width;
44     const int imageHeight = image.size.height;
45     size_t bytesPerRow = imageWidth * 4;
46     uint32_t* rgbImageBuf = (uint32_t*)malloc(bytesPerRow * imageHeight);
47
48     //Create context
49     CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
50     CGContextRef contextRef = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpaceRef, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
51     CGContextDrawImage(contextRef, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
52
53     //Traverse pixe
54     int pixelNum = imageWidth * imageHeight;
55     uint32_t* pCurPtr = rgbImageBuf;
56     for (int i = 0; i < pixelNum; i++, pCurPtr++){
57         if ((*pCurPtr & 0xFFFFFF00) < 0x99999900){
58             //Change color
59             uint8_t* ptr = (uint8_t*)pCurPtr;
60             ptr[3] = red; //0~255
61             ptr[2] = green;
62             ptr[1] = blue;
63         }else{
64             uint8_t* ptr = (uint8_t*)pCurPtr;
65             ptr[0] = 0;
66         }
67     }
68
69     //Convert to image
70     CGDataProviderRef dataProviderRef = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
71     CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpaceRef,
72                                         kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProviderRef,
73                                         NULL, true, kCGRenderingIntentDefault);
74     CGDataProviderRelease(dataProviderRef);
75     UIImage* img = [UIImage imageWithCGImage:imageRef];
76
77     //Release
78     CGImageRelease(imageRef);
79     CGContextRelease(contextRef);
80     CGColorSpaceRelease(colorSpaceRef);
81     return img;
82 }
83
84 +(UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withIconSize:(CGSize)iconSize {
85     UIGraphicsBeginImageContext(image.size);
86     //通过两张图片进行位置和大小的绘制，实现两张图片的合并；其实此原理做法也可以用于多张图片的合并
87     CGFloat widthOfImage = image.size.width;
88     CGFloat heightOfImage = image.size.height;
89     CGFloat widthOfIcon = iconSize.width;
90     CGFloat heightOfIcon = iconSize.height;
91
92     [image drawInRect:CGRectMake(0, 0, widthOfImage, heightOfImage)];
93     [icon drawInRect:CGRectMake((widthOfImage-widthOfIcon)/2, (heightOfImage-heightOfIcon)/2,
94                                 widthOfIcon, heightOfIcon)];
95     UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
96
97     UIGraphicsEndImageContext();
98     return img;
99 }
100
101 +(UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withScale:(CGFloat)scale {
102     UIGraphicsBeginImageContext(image.size);
103
104     //通过两张图片进行位置和大小的绘制，实现两张图片的合并；其实此原理做法也可以用于多张图片的合并
105     CGFloat widthOfImage = image.size.width;
106     CGFloat heightOfImage = image.size.height;
107     CGFloat widthOfIcon = widthOfImage/scale;
108     CGFloat heightOfIcon = heightOfImage/scale;
109
110     [image drawInRect:CGRectMake(0, 0, widthOfImage, heightOfImage)];
111     [icon drawInRect:CGRectMake((widthOfImage-widthOfIcon)/2, (heightOfImage-heightOfIcon)/2,
112                                 widthOfIcon, heightOfIcon)];
113     UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
114
115     UIGraphicsEndImageContext();
116     return img;
117 }
118
119 @end