生成二维码代码

#pragma mark -- 创建二维码图片 - (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)Imagesize logoImageSize:(CGFloat)waterImagesize{ CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; [filter setDefaults]; NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding]; [filter setValue:data forKey:@"inputMessage"];//通过kvo方式给一个字符串，生成二维码 [filter setValue:@"H" forKey:@"inputCorrectionLevel"];//设置二维码的纠错水平，越高纠错水平越高，可以污损的范围越大 CIImage *outPutImage = [filter outputImage];//拿到二维码图片 return [self createNonInterpolatedUIImageFormCIImage:outPutImage withSize:Imagesize waterImageSize:waterImagesize]; } - (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size waterImageSize:(CGFloat)waterImagesize{ CGRect extent = CGRectIntegral(image.extent); CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent)); // 1.创建bitmap; size_t width = CGRectGetWidth(extent) * scale; size_t height = CGRectGetHeight(extent) * scale; //创建一个DeviceGray颜色空间 CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray(); //CGBitmapContextCreate(void * _Nullable data, size_t width, size_t height, size_t bitsPerComponent, size_t bytesPerRow, CGColorSpaceRef _Nullable space, uint32_t bitmapInfo) //width：图片宽度像素 //height：图片高度像素 //bitsPerComponent：每个颜色的比特值，例如在rgba-32模式下为8 //bitmapInfo：指定的位图应该包含一个alpha通道。 CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone); CIContext *context = [CIContext contextWithOptions:nil]; //创建CoreGraphics image CGImageRef bitmapImage = [context createCGImage:image fromRect:extent]; CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone); CGContextScaleCTM(bitmapRef, scale, scale); CGContextDrawImage(bitmapRef, extent, bitmapImage); // 2.保存bitmap到图片 CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef); CGContextRelease(bitmapRef); CGImageRelease(bitmapImage); //原图 UIImage *outputImage = [UIImage imageWithCGImage:scaledImage]; //给二维码加 logo 图 UIGraphicsBeginImageContextWithOptions(outputImage.size, NO, [[UIScreen mainScreen] scale]); [outputImage drawInRect:CGRectMake(0,0 , size, size)]; //logo图 UIImage *waterimage = [UIImage imageNamed:@"logo_icon"]; //把logo图画到生成的二维码图片上，注意尺寸不要太大（最大不超过二维码图片的%30），太大会造成扫不出来 [waterimage drawInRect:CGRectMake((size-waterImagesize)/2.0, (size-waterImagesize)/2.0, waterImagesize, waterImagesize)]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return newPic; }