IOS创建二维码

迈不过友情╰ 2023-10-16 22:36 33阅读 0赞

//调用
        UIImage *qrcode = [self createNonInterpolatedUIImageFormCIImage:[self createQRForString:@"http://www.baidu.com"] withSize:190.0f];
        UIImage *customQrcode = [self imageBlackToTransparent:qrcode withRed:0.0f andGreen:0.0f andBlue:0.0f];
        self.erweimaImg.image = customQrcode;

#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;
    }