生成二維碼代碼

#pragma mark -- 創建二維碼圖片 - (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"];//通過kvo方式給一個字符串，生成二維碼 [filter setValue:@"H" forKey:@"inputCorrectionLevel"];//設置二維碼的糾錯水平，越高糾錯水平越高，可以污損的範圍越大 CIImage *outPutImage = [filter outputImage];//拿到二維碼圖片 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.創建bitmap; size_t width = CGRectGetWidth(extent) * scale; size_t height = CGRectGetHeight(extent) * scale; //創建一個DeviceGray顏色空間 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：圖片寬度像素 //height：圖片高度像素 //bitsPerComponent：每個顏色的比特值，例如在rgba-32模式下爲8 //bitmapInfo：指定的位圖應該包含一個alpha通道。 CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone); CIContext *context = [CIContext contextWithOptions:nil]; //創建CoreGraphics image CGImageRef bitmapImage = [context createCGImage:image fromRect:extent]; CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone); CGContextScaleCTM(bitmapRef, scale, scale); CGContextDrawImage(bitmapRef, extent, bitmapImage); // 2.保存bitmap到圖片 CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef); CGContextRelease(bitmapRef); CGImageRelease(bitmapImage); //原圖 UIImage *outputImage = [UIImage imageWithCGImage:scaledImage]; //給二維碼加 logo 圖 UIGraphicsBeginImageContextWithOptions(outputImage.size, NO, [[UIScreen mainScreen] scale]); [outputImage drawInRect:CGRectMake(0,0 , size, size)]; //logo圖 UIImage *waterimage = [UIImage imageNamed:@"logo_icon"]; //把logo圖畫到生成的二維碼圖片上，注意尺寸不要太大（最大不超過二維碼圖片的%30），太大會造成掃不出來 [waterimage drawInRect:CGRectMake((size-waterImagesize)/2.0, (size-waterImagesize)/2.0, waterImagesize, waterImagesize)]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return newPic; }