How to go to new viewcontroller after scanning a QR code?

Question

I tried for many hours now to try and get my application to work. The problem is that after the app detects a QR-code, it does not show the new view controller. It will perform a simple print statement in that new view controller to the log, but there is no new view controller present in the app. I tried many solutions already on Stackoverflow, but none seems to be helping in this specific case.

func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) {
    captureSession.stopRunning()

    if let metadataObject = metadataObjects.first {
        let readableObject = metadataObject as! AVMetadataMachineReadableCodeObject;

        AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
        found(code: readableObject.stringValue);

    }
    let vc = infoViewController()
    self.present(vc, animated: true, completion: nil)

I Use the last to lines to point to the new infoViewController the app is supposed to go to after scanning a QR-code. The code in the infoViewController is as follows:

import UIKit

class infoViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        print("Hi")
}

The Log does show the print statement "Hi", but the application does not go to the infoViewController. The storyboard also has the infoViewController in it, with the class infoViewController selected.

Is there a detail that I'm missing currently?

Greetings

If you want to present ViewController it should be from other ViewController. — Zuzana Paulis, Jan 12 '17 at 15:50
Does it get into ViewWillAppear method? Also you should place breakpoint into ViewDidLoad and inspect values. — Zuzana Paulis, Jan 12 '17 at 15:55
@ZuzanaPaulis Hi, no it does not go into ViewWillAppear method :o, this method is as follows: override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) print("Hi2") } — Jelleko, Jan 12 '17 at 16:01
You did not answered what class is Self in `self.present(vc, animated: true, completion: nil)`. — Zuzana Paulis, Jan 12 '17 at 16:02
@ZuzanaPaulis the self.present is in class: ScannerViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate — Jelleko, Jan 12 '17 at 16:05
Try to make breakpoint in ViewDidLoad, does your InfoViewController have assigned View? — Zuzana Paulis, Jan 12 '17 at 16:08
I think your View controller does not have View so he could not present it. — Zuzana Paulis, Jan 12 '17 at 16:09
@ZuzanaPaulis How should I add a View? :o not sure how you mean that it does not have a View. — Jelleko, Jan 12 '17 at 16:30
Why don't you make a segue instead to present the view controller? — pableiros, Jan 12 '17 at 16:35
@pableiros The thing is, I can get the view controller to show if I use a button, but I can't get it to show the new view controller automatically, after the camera detects a QR-Code — Jelleko, Jan 13 '17 at 09:15

score 0 · Answer 1 · answered Jan 12 '17 at 16:17

0

First you have to select the infoViewController on your storyboard and in the Identity inspector, you have to add a Storyboard ID like this:

Then you have to present the infoViewController like this:

OperationQueue.main.addOperation {
    let infoViewController = self.storyboard?.instantiateViewController(withIdentifier: "infoViewController"
    self.present(infoViewController, animated: true)
}

answered Jan 12 '17 at 16:17

pableiros

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Not working unfortunately, It will also not enter the viewDidLoad function :'( – Jelleko Jan 12 '17 at 16:31
Did you set the `infoViewController` class to the `ViewController` in the storyboard? – pableiros Jan 12 '17 at 16:32

How to go to new viewcontroller after scanning a QR code?

1 Answers1