二维码和条形码

1.二维码

/*************二维码*************/
#pragma mark - InterpolatedUIImage
+ (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
    // create a bitmap image that we'll draw into a bitmap context at the desired size;
    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);
    // Create an image with the contents of our bitmap
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    // Cleanup
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

#pragma mark - QRCodeGenerator
+ (CIImage *)createQRForString:(NSString *)qrString {
    // Need to convert the string to a UTF-8 encoded NSData object
    NSData *stringData = [qrString dataUsingEncoding:NSUTF8StringEncoding];
    // Create the filter
    CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    // Set the message content and error-correction level
    [qrFilter setValue:stringData forKey:@"inputMessage"];
    [qrFilter setValue:@"M" forKey:@"inputCorrectionLevel"];
    // Send the image back
    return qrFilter.outputImage;
}

#pragma mark - imageToTransparent
void ProviderReleaseData (void *info, const void *data, size_t size){
    free((void*)data);
}


+ (UIImage*)imageBlackToTransparent:(UIImage*)image withRed:(CGFloat)red andGreen:(CGFloat)green andBlue:(CGFloat)blue{
    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);
    // create context
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace,
                                                 kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
    // traverse pixe
    int pixelNum = imageWidth * imageHeight;
    uint32_t* pCurPtr = rgbImageBuf;
    for (int i = 0; i < pixelNum; i++, pCurPtr++){
        if ((*pCurPtr & 0xFFFFFF00) < 0x99999900){
            // change color
            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;
        }
    }
    // context to image
    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);
    UIImage* resultUIImage = [UIImage imageWithCGImage:imageRef];
    // release
    CGImageRelease(imageRef);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    return resultUIImage;
}

2.条形码

/*************条形码*************/
/*
 *  生成条形码

 *
 *  @return 生成条形码的CIImage对象
 */
+ (CIImage *) generateBarCodeImage:(NSString *)source
{
    // iOS 8.0以上的系统才支持条形码的生成，iOS8.0以下使用第三方控件生成
    if ([[UIDevice currentDevice].systemVersion floatValue] >= 8.0) {
        // 注意生成条形码的编码方式
        NSData *data = [source dataUsingEncoding: NSASCIIStringEncoding];
        CIFilter *filter = [CIFilter filterWithName:@"CICode128BarcodeGenerator"];
        [filter setValue:data forKey:@"inputMessage"];
        // 设置生成的条形码的上，下，左，右的margins的值
        [filter setValue:[NSNumber numberWithInteger:0] forKey:@"inputQuietSpace"];
        return filter.outputImage;
    }else{
        return nil;
    }
}

/**
 *  调整生成的图片的大小
 *
 *  @param image CIImage对象
 *  @param size  需要的UIImage的大小
 *
 *  @return size大小的UIImage对象
 */
+(UIImage *) resizeCodeImage:(CIImage *)image withSize:(CGSize)size
{
    if (image) {
        CGRect extent = CGRectIntegral(image.extent);
        CGFloat scaleWidth = size.width/CGRectGetWidth(extent);
        CGFloat scaleHeight = size.height/CGRectGetHeight(extent);
        size_t width = CGRectGetWidth(extent) * scaleWidth;
        size_t height = CGRectGetHeight(extent) * scaleHeight;
        CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceGray();
        CGContextRef contentRef = CGBitmapContextCreate(nil, width, height, 8, 0, colorSpaceRef, (CGBitmapInfo)kCGImageAlphaNone);
        CIContext *context = [CIContext contextWithOptions:nil];
        CGImageRef imageRef = [context createCGImage:image fromRect:extent];
        CGContextSetInterpolationQuality(contentRef, kCGInterpolationNone);
        CGContextScaleCTM(contentRef, scaleWidth, scaleHeight);
        CGContextDrawImage(contentRef, extent, imageRef);
        CGImageRef imageRefResized = CGBitmapContextCreateImage(contentRef);
        CGContextRelease(contentRef);
        CGImageRelease(imageRef);
        return [UIImage imageWithCGImage:imageRefResized];
    }else{
        return nil;
    }
}

3.demo链接