iOS实现二维码的彩色效果

今天做项目基本是完成了，测试也进入尾声，同事给我说要我把二维码变成彩色的，我对着原来前辈写的工程研究来研究去，找了很多资料还是没弄好，还是一直失败，于是找了一下我同学，问了一下他，结果他上班没时间帮我看，但是却帮我开了脑洞，我突然发现自己太死板了，死磕在原来代码上，其实到github上搜一搜有很多写好的代码供我使用，但是我没有想到，工作是讲究效率的，学习可以死磕，但是工作上一定要头脑灵活，学会使用八方资源，把自己的工作效率大大提高，受教。

把今天使用的二维码生成与大家分享。Demo地址：点击打开链接

QRCodeImage.h

#import <UIKit/UIKit.h>@interface QRCodeImage : UIImage/** *  1.生成一个二维码 * *  @param string 字符串 *  @param width  二维码宽度 * *  @return <#return value description#> */+ (QRCodeImage *_Nonnull)codeImageWithString:(NSString *_Nullable)string                                        size:(CGFloat)width;/** *  2.生成一个二维码 * *  @param string 字符串 *  @param width  二维码宽度 *  @param color  二维码颜色 * *  @return <#return value description#> */+ (QRCodeImage *_Nonnull)codeImageWithString:(NSString *_Nullable)string                                        size:(CGFloat)width                                       color:(UIColor *_Nullable)color;/** *  3.生成一个二维码 * *  @param string    字符串 *  @param width     二维码宽度 *  @param color     二维码颜色 *  @param icon      头像 *  @param iconWidth 头像宽度，建议宽度小于二维码宽度的1/4 * *  @return <#return value description#> */+ (QRCodeImage *_Nonnull)codeImageWithString:(NSString *_Nullable)string                                        size:(CGFloat)width                                       color:(UIColor *_Nullable)color                                        icon:(UIImage *_Nullable)icon                                   iconWidth:(CGFloat)iconWidth;@end

QRCodeImage.m

#import "QRCodeImage.h"@implementation QRCodeImage+ (QRCodeImage *)codeImageWithString:(NSString *)string                                size:(CGFloat)width{    CIImage *ciImage = [QRCodeImage createQRForString:string];    if (ciImage) {        return [QRCodeImage createNonInterpolatedUIImageFormCIImage:ciImage                                                               size:width];    } else {        return nil;    }}+ (QRCodeImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image                                                    size:(CGFloat)size {        CGRect extent = CGRectIntegral(image.extent);    CGFloat scale = MIN(size/CGRectGetWidth(extent),                        size/CGRectGetHeight(extent));    // 1.创建一个位图图像，绘制到其大小的位图上下文    size_t width        = CGRectGetWidth(extent) * scale;    size_t height       = CGRectGetHeight(extent) * scale;    CGColorSpaceRef cs  = CGColorSpaceCreateDeviceGray();    CGContextRef bitmapRef = CGBitmapContextCreate(nil,                                                   width,                                                   height,                                                   8,                                                   0,                                                   cs,                                                   (CGBitmapInfo)kCGImageAlphaNone);    CIContext *context     = [CIContext contextWithOptions:nil];    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);    CGContextScaleCTM(bitmapRef, scale, scale);    CGContextDrawImage(bitmapRef, extent, bitmapImage);    // 2.创建具有内容的位图图像    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);    // 3.清理    CGContextRelease(bitmapRef);    CGImageRelease(bitmapImage);    return (QRCodeImage*)[UIImage imageWithCGImage:scaledImage];}+ (CIImage *)createQRForString:(NSString *)qrString {    // 1.将字符串转换为UTF8编码的NSData对象    NSData *stringData = [qrString dataUsingEncoding:NSUTF8StringEncoding];    // 2.创建filter    CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];    // 3.设置内容和纠错级别    [qrFilter setValue:stringData forKey:@"inputMessage"];    [qrFilter setValue:@"M" forKey:@"inputCorrectionLevel"];    // 4.返回CIImage    return qrFilter.outputImage;}void ProviderReleaseData (void *info, const void *data, size_t size){    free((void*)data);}+ (QRCodeImage *_Nonnull)codeImageWithString:(NSString *_Nullable)string                                        size:(CGFloat)width                                       color:(UIColor *_Nullable)color;{            QRCodeImage *image = [QRCodeImage codeImageWithString:string size:width];        const CGFloat *components = CGColorGetComponents(color.CGColor);    CGFloat red     = components[0]*255;    CGFloat green   = components[1]*255;    CGFloat blue    = components[2]*255;        const int imageWidth    = image.size.width;    const int imageHeight   = image.size.height;    size_t      bytesPerRow = imageWidth * 4;    uint32_t* rgbImageBuf   = (uint32_t*)malloc(bytesPerRow * imageHeight);        // 1.创建上下文    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();    CGContextRef context = CGBitmapContextCreate(rgbImageBuf,                                                 imageWidth,                                                 imageHeight,                                                 8,                                                 bytesPerRow,                                                 colorSpace,                                                 kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);        // 2.像素转换    int pixelNum = imageWidth * imageHeight;    uint32_t* pCurPtr = rgbImageBuf;    for (int i = 0; i < pixelNum; i++, pCurPtr++){        if ((*pCurPtr & 0xFFFFFF00) < 0x99999900){            uint8_t* ptr = (uint8_t*)pCurPtr;            ptr[3] = red; //0~255            ptr[2] = green;            ptr[1] = blue;        }else{            uint8_t* ptr = (uint8_t*)pCurPtr;            ptr[0] = 0;        }    }        // 3.生成UIImage    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL,                                                                  rgbImageBuf,                                                                  bytesPerRow * imageHeight,                                                                  ProviderReleaseData);    CGImageRef imageRef = CGImageCreate(imageWidth,                                        imageHeight,                                        8,                                        32,                                        bytesPerRow,                                        colorSpace,                                        kCGImageAlphaLast | kCGBitmapByteOrder32Little,                                        dataProvider,                                        NULL,                                        true,                                        kCGRenderingIntentDefault);    CGDataProviderRelease(dataProvider);    QRCodeImage* resultUIImage = (QRCodeImage*)[UIImage imageWithCGImage:imageRef];        // 4.释放    CGImageRelease(imageRef);    CGContextRelease(context);    CGColorSpaceRelease(colorSpace);        return resultUIImage;}+ (QRCodeImage *_Nonnull)codeImageWithString:(NSString *_Nullable)string                                        size:(CGFloat)width                                       color:(UIColor *_Nullable)color                                        icon:(UIImage *_Nullable)icon                                    iconWidth:(CGFloat)iconWidth{    QRCodeImage *bgImage = [QRCodeImage codeImageWithString:string                                                       size:width                                                      color:color];    UIGraphicsBeginImageContext(bgImage.size);    [bgImage drawInRect:CGRectMake(0, 0, bgImage.size.width, bgImage.size.height)];        CGFloat x = (bgImage.size.width - iconWidth) * 0.5;    CGFloat y = (bgImage.size.height - iconWidth) * 0.5;    [icon drawInRect:CGRectMake( x,  y, iconWidth,  iconWidth)];        UIImage *newImage =  UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return (QRCodeImage *)newImage;}@end

使用方法

QRCodeImage *qrCodeImage = [QRCodeImage codeImageWithString:@"https://github.com/EmyWong/PersonalUITech"                                                           size:200                                                          color:[UIColor orangeColor]                                                           ];    UIImageView *qrImageView = [[UIImageView alloc]initWithImage:qrCodeImage];    qrImageView.center = self.view.center;    [self.view addSubview:qrImageView];    self.qrImageView = qrImageView;

快来把你的二维码变成彩色的吧~