iOS二维码、条形码生成（可指定大小、颜色）

一、前言： 
iOS7.0之后可以利用系统原生 API 生成二维码, iOS8.0之后可以生成条形码, 系统默认生成的颜色是黑色. 在这里, 利用以下方法可以生成指定大小、指定颜色的二维码和条形码, 还可以添加背景颜色、阴影效果, 以下是具体方法.

二、二维码生成 
因为返回的都是UIImage 所以我写了一个UIImage的分类

// UIimage(QRCode).h 文件
//Avilable in iOS 7.0 and later
+ (UIImage *)qrCodeImageWithContent:(NSString *)content
                      codeImageSize:(CGFloat)size
                               logo:(UIImage *)logo
                          logoFrame:(CGRect)logoFrame
                                red:(CGFloat)red
                              green:(CGFloat)green
                               blue:(NSInteger)blue;

// UIimage(QRCode).m 实现文件
#pragma mark - 生成二维码
+ (UIImage *)qrCodeImageWithContent:(NSString *)content
                      codeImageSize:(CGFloat)size
                               logo:(UIImage *)logo
                          logoFrame:(CGRect)logoFrame
                                red:(CGFloat)red
                              green:(CGFloat)green
                               blue:(NSInteger)blue{

    UIImage *image = [self qrCodeImageWithContent:content codeImageSize:size red:red green:green blue:blue];
    //有 logo 则绘制 logo
    if (logo != nil) {
        UIGraphicsBeginImageContext(image.size);
        [image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
        [logo drawInRect:logoFrame];
        UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return resultImage;
    }else{
        return image;
    }

}

//改变二维码颜色
+ (UIImage *)qrCodeImageWithContent:(NSString *)content codeImageSize:(CGFloat)size red:(CGFloat)red green:(CGFloat)green blue:(NSInteger)blue{
    UIImage *image = [self qrCodeImageWithContent:content codeImageSize:size];
    int imageWidth = image.size.width;
    int imageHeight = image.size.height;
    size_t bytesPerRow = imageWidth * 4;
    uint32_t *rgbImageBuf = (uint32_t *)malloc(bytesPerRow * imageHeight);
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpaceRef, kCGBitmapByteOrder32Little|kCGImageAlphaNoneSkipLast);
    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
    //遍历像素, 改变像素点颜色
    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*255;
            ptr[2] = green*255;
            ptr[1] = blue*255;
        }else{
            uint8_t* ptr = (uint8_t*)pCurPtr;
            ptr[0] = 0;
        }
    }
    //取出图片
    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
    CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpaceRef,
                                        kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider,
                                        NULL, true, kCGRenderingIntentDefault);
    CGDataProviderRelease(dataProvider);
    UIImage *resultImage = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpaceRef);

    return resultImage;
}

//改变二维码尺寸大小
+ (UIImage *)qrCodeImageWithContent:(NSString *)content codeImageSize:(CGFloat)size{
    CIImage *image = [self qrCodeImageWithContent:content];
    CGRect integralRect = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(integralRect), size/CGRectGetHeight(integralRect));

    size_t width = CGRectGetWidth(integralRect)*scale;
    size_t height = CGRectGetHeight(integralRect)*scale;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, colorSpaceRef, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef bitmapImage = [context createCGImage:image fromRect:integralRect];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, integralRect, bitmapImage);

    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

//生成最原始的二维码
+ (CIImage *)qrCodeImageWithContent:(NSString *)content{
    CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    NSData *contentData = [content dataUsingEncoding:NSUTF8StringEncoding];
    [qrFilter setValue:contentData forKey:@"inputMessage"];
    [qrFilter setValue:@"H" forKey:@"inputCorrectionLevel"];
    CIImage *image = qrFilter.outputImage;
    return image;
}

void ProviderReleaseData (void *info, const void *data, size_t size){
    free((void*)data);
}

三、条形码生成

// .h文件
#pragma mark - 生成条形码
//Avilable in iOS 8.0 and later
+ (UIImage *)barcodeImageWithContent:(NSString *)content
                       codeImageSize:(CGSize)size
                                 red:(CGFloat)red
                               green:(CGFloat)green
                                blue:(NSInteger)blue;

#pragma mark - 生成条形码
+ (UIImage *)barcodeImageWithContent:(NSString *)content codeImageSize:(CGSize)size red:(CGFloat)red green:(CGFloat)green blue:(NSInteger)blue{
    UIImage *image = [self barcodeImageWithContent:content codeImageSize:size];
    int imageWidth = image.size.width;
    int imageHeight = image.size.height;
    size_t bytesPerRow = imageWidth * 4;
    uint32_t *rgbImageBuf = (uint32_t *)malloc(bytesPerRow * imageHeight);
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpaceRef, kCGBitmapByteOrder32Little|kCGImageAlphaNoneSkipLast);
    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
    //遍历像素, 改变像素点颜色
    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*255;
            ptr[2] = green*255;
            ptr[1] = blue*255;
        }else{
            uint8_t* ptr = (uint8_t*)pCurPtr;
            ptr[0] = 0;
        }
    }
    //取出图片
    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
    CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpaceRef,
                                        kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider,
                                        NULL, true, kCGRenderingIntentDefault);
    CGDataProviderRelease(dataProvider);
    UIImage *resultImage = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpaceRef);

    return resultImage;
}

//改变条形码尺寸大小
+ (UIImage *)barcodeImageWithContent:(NSString *)content codeImageSize:(CGSize)size{
    CIImage *image = [self barcodeImageWithContent:content];
    CGRect integralRect = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size.width/CGRectGetWidth(integralRect), size.height/CGRectGetHeight(integralRect));

    size_t width = CGRectGetWidth(integralRect)*scale;
    size_t height = CGRectGetHeight(integralRect)*scale;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, colorSpaceRef, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef bitmapImage = [context createCGImage:image fromRect:integralRect];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, integralRect, bitmapImage);

    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

//生成最原始的条形码
+ (CIImage *)barcodeImageWithContent:(NSString *)content{
    CIFilter *qrFilter = [CIFilter filterWithName:@"CICode128BarcodeGenerator"];
    NSData *contentData = [content dataUsingEncoding:NSUTF8StringEncoding];
    [qrFilter setValue:contentData forKey:@"inputMessage"];
    [qrFilter setValue:@(0.00) forKey:@"inputQuietSpace"];
    CIImage *image = qrFilter.outputImage;
    return image;
}

void ProviderReleaseData (void *info, const void *data, size_t size){
    free((void*)data);
}

四、测试

// 在控制器中实现
self.title = @"二维码和条形码";

    //条形码
    UIImage *barImage = [UIImage barcodeImageWithContent:@"123456"
                                             codeImageSize:CGSizeMake(300, 90)
                                                       red:0
                                                     green:0.4
                                                      blue:0.6];
    CGRect barImageView_Frame = CGRectMake(self.view.bounds.size.width/2-300/2, 100, 300, 90);
    UIImageView *barImageView = [[UIImageView alloc] initWithFrame:barImageView_Frame];
    barImageView.image = barImage;
    barImageView.backgroundColor = [UIColor clearColor];
    //阴影
    barImageView.layer.shadowOffset = CGSizeMake(-0.5, 0.5);
    barImageView.layer.shadowRadius = 0.5;
    barImageView.layer.shadowColor = [UIColor blackColor].CGColor;
    barImageView.layer.shadowOpacity = 0.2;

    [self.view addSubview:barImageView];

    //二维码
    UIImage *qrCodeImage = [UIImage qrCodeImageWithContent:@"15280107764"
                                               codeImageSize:200
                                                      logo:[UIImage imageNamed:@"avatar"]
                                                   logoFrame:CGRectMake(75, 75, 50, 50)
                                                         red:0.0f
                                                       green:139/255.0f
                                                        blue:139/255.0f];
    CGRect qrCodeImageView_Frame = CGRectMake(self.view.bounds.size.width/2-200/2, CGRectGetMaxY(barImageView.frame)+20, 200, 200);
    UIImageView *qrCodeImageView = [[UIImageView alloc] initWithFrame:qrCodeImageView_Frame];
    qrCodeImageView.image = qrCodeImage;
    qrCodeImageView.backgroundColor = [UIColor whiteColor];// #006400
    //阴影
    qrCodeImageView.layer.shadowOffset = CGSizeMake(0, 0);
    qrCodeImageView.layer.shadowRadius = 5;
    qrCodeImageView.layer.shadowColor = [UIColor blackColor].CGColor;
    qrCodeImageView.layer.shadowOpacity = 0.4;

    [self.view addSubview:qrCodeImageView];

// 参考来源 http://www.jianshu.com/p/b893690b472e