Is there a way to generate QR code image on iOS

Question

Is there a standard way to generate a QR code and attach it to a mail item from iOS client app (no server code)?

Answer 1

Since iOS 7, you can use a Core Image filter to generate QR images. See the final tip here:

- (CIImage *)createQRForString:(NSString *)qrString {     NSData *stringData = [qrString dataUsingEncoding: NSISOLatin1StringEncoding];      CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];     [qrFilter setValue:stringData forKey:@"inputMessage"];      return qrFilter.outputImage; } 

Answer 2

For Obj-C version that perfectly works for me, I've mixed answers पवन and Teja Kumar Bethina:

NSString *qrString = @"My string to encode"; NSData *stringData = [qrString dataUsingEncoding: NSUTF8StringEncoding];  CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; [qrFilter setValue:stringData forKey:@"inputMessage"]; [qrFilter setValue:@"H" forKey:@"inputCorrectionLevel"];  CIImage *qrImage = qrFilter.outputImage; float scaleX = self.qrImageView.frame.size.width / qrImage.extent.size.width; float scaleY = self.qrImageView.frame.size.height / qrImage.extent.size.height;  qrImage = [qrImage imageByApplyingTransform:CGAffineTransformMakeScale(scaleX, scaleY)];  self.qrImageView.image = [UIImage imageWithCIImage:qrImage                                              scale:[UIScreen mainScreen].scale                                        orientation:UIImageOrientationUp];