IOS创建二维码

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清雨小竹 发表于 2022/09/25 00:04:40 2022/09/25
【摘要】 //调用 UIImage *qrcode = [self createNonInterpolatedUIImageFormCIImage:[self createQRForString:@"http://www.baidu.com"] withSize:190.0f]; UIImage *customQrcode = [...


      //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;
      }
  
 


文章来源: zzzili.blog.csdn.net,作者:清雨小竹,版权归原作者所有,如需转载,请联系作者。

原文链接:zzzili.blog.csdn.net/article/details/49759121

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