How to create a QR Code reader for iOS - objective-c

Question

I am developing an app for our local business. I already have the live camera in a UIImageView, now I need to know how to read QR codes from the UIImageView and display the content (0000-KKP0-2013) in a label.
So basically I need a QR code scanner which is reading a QR code and save the content in a String. I already used ZXing ("Zebra Crossing") but it is not compatible with iOS 6 and it won't work. Is there an easy code for getting the QR Code content in a String?
Thank you!
This is the code I am using in my .m file:
#import "ZBarSDK.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize vImagePreview;
- (void)viewDidUnload
{
[super viewDidUnload];
vImagePreview = nil;
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
//----- SHOW LIVE CAMERA PREVIEW -----
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPreset352x288;
/*CALayer *viewLayer = self.vImagePreview.layer;
NSLog(#"viewLayer = %#", viewLayer);*/
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = self.vImagePreview.bounds;
[self.vImagePreview.layer addSublayer:captureVideoPreviewLayer];
AVCaptureDevice *device = [self frontCamera];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
// Handle the error appropriately.
NSLog(#"ERROR: trying to open camera: %#", error);
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:#"QReader"
message:[NSString stringWithFormat:#"ERROR: Versuch die Kamera zu öffnen ist fehlgeschlagen [%#]",error]
delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
alert.tag = 1;
[alert show];
}
[session addInput:input];
[session startRunning];
}
- (AVCaptureDevice *)frontCamera {
NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
for (AVCaptureDevice *device in devices) {
if ([device position] == AVCaptureDevicePositionFront) {
return device;
}
}
return nil;
}
Now I need to know how to read the QR code from the vImagePreview with the ZBarSDK. And I cant use a UIPickerView

Answer 1

Try ZBar: http://zbar.sourceforge.net/iphone/sdkdoc/install.html
We are using it successfully in our application which supports iOS 4 up to iOS 6.1
In my case I use ZBarReaderView - to see a camera preview, which automatically detects and returns scanned code.
You'll need:
#import "ZBarSDK.h"
ZBarReaderView *readerView;
add this : <ZBarReaderViewDelegate>
and then:
[readerView.scanner setSymbology:ZBAR_QRCODE config:ZBAR_CFG_ENABLE to:0];
readerView.readerDelegate = self;
[readerView start];
- (void)readerView:(ZBarReaderView *)view didReadSymbols: (ZBarSymbolSet *)syms fromImage:(UIImage *)img
{
for(ZBarSymbol *sym in syms)
{
NSLog(#"Did read symbols: %#", sym.data);
}
}
Anyways, just follow these instructions:
http://zbar.sourceforge.net/iphone/sdkdoc/tutorial.html
and then try it out - see if it works for You.
EDIT
Here I uploaded example project I took from here: https://github.com/arciem/ZBarSDK
It has enabled front facing camera. Tested - successfully reads qr code using front facing camera:
http://www.speedyshare.com/fkvqt/download/readertest.zip
or
Once application starts - front camera is shown - scanner is 200x200 large and as a subview.
http://www.speedyshare.com/QZZU5/download/ReaderSample-v3.zip

Answer 2

We looked into this not long ago. ZBar looks good, but it's LGPL-licensed, which is not suitable for use on the App Store. In the end I went with ZXingObjC.

Answer 3

if you want to test the qr codes here are some apps for iphone that might come in handy. iphone qr scanner

Answer 4

OP was looking for something that supported iOS6 two years ago, but for anyone else coming along, this one that I went with wraps the built-in iOS7 functionality:
https://github.com/mikebuss/MTBBarcodeScanner

Answer 5

Anyone looking to implement this in Swift. Check this out:
https://github.com/aeieli/swiftQRCode
Need to change a few syntax errors, otherwise fully working on iOS 8.1

Answer 6

Check this out with apple natively implemented Qr code