objective C unable to switch views after scanning a QR code using ZBar - iphone

Question

I am developping an App using XCode 4.2 that detects a QR code.
I am trying to make a switch view after QR code detection but it is not working at all
here is the code am using :
- (void) imagePickerController: (UIImagePickerController*) reader
didFinishPickingMediaWithInfo: (NSDictionary*) info
{
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
// ADD: get the decode results
id<NSFastEnumeration> results =
[info objectForKey: ZBarReaderControllerResults];
ZBarSymbol *symbol = nil;
for(symbol in results)
break;
NSString *string=symbol.data;
NSString *string2=#"1234";
if ([string isEqualToString:string2]) {
//this is the part that is not working : it doesn t load the AboutView at all
AboutView *about = [[AboutView alloc] initWithNibName:nil bundle:nil];
[self presentModalViewController:about animated:YES];
}
else{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error"
message:#"This is not a recognized QR code!"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
}
// ADD: dismiss the controller (NB dismiss from the *reader*!)
[reader dismissModalViewControllerAnimated: YES];
}
thanks

Answer 1

The issue is that the reader is the presented view controller in zbar's example code
-(void)presentReaderInViewController:(UIViewController*)vc
and you are treating self as if it is presented
You should use reader to present your AboutView and only dismiss reader in the else block
if ([string isEqualToString:string2]) {
//this is the part that is not working : it doesn t load the AboutView at all
AboutView *about = [[AboutView alloc] initWithNibName:nil bundle:nil];
[reader presentModalViewController:about animated:YES];
}
else{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error"
message:#"This is not a recognized QR code!"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
// ADD: dismiss the controller (NB dismiss from the *reader*!)
[reader dismissModalViewControllerAnimated: YES];
}
You might also want to wait to dismiss reader in the delegate method of your alert view (create a soft reference and dismiss that... myReader = reader; when you set up the alertview)
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex{
[myReader dismissModalViewControllerAnimated: YES];
}