Swift - 推送和弹出 UIViewcontroller 不工作

Question

I am having problems with my ViewControllers . Does anyone know why that code is not working? The print function work...

A to B

    @IBAction func editButtonTapped(_ sender: Any) {
    let imageCollectionView = self.storyboard?.instantiateViewController(withIdentifier: "ImageCollectionVC") as! ImageCollectionViewController
    imageCollectionView.delegate = self
    self.navigationController?.pushViewController(imageCollectionView, animated: true)
    print("editButtonTapped")
}



}

    extension ExampleViewController: ClassBDelegate {
            func childVCDidComplete( with image: UIImage?) {
                self.pickedImage = image!
            }
    }

B to A

 protocol ClassBDelegate {
    func childVCDidComplete(with image: UIImage?)
}

class ImageCollectionViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout{

    @IBOutlet weak var imageCollectionView: UICollectionView!

    var delegate: ClassBDelegate?
var tappedImage = UIImage()

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
   tappedImage = images[indexPath.row]
   delegate?.childVCDidComplete(with: tappedImage)
   navigationController?.popViewController(animated: true)
}

That is my full project: https://github.com/chriskonnerth/Wishlist

ViewController A in my case is ExampleViewController and B is ImageCollectionViewController

UPDATE

that is my Storyboard:

ImageViewController is the right one and ExampleViewController is the one left to it.

Answer 1

Check navigationController instance in below line of code:

self.navigationController?.pushViewController(imageCollectionView, animated: true)

If self.navigationController is nil then you may have not embedded navigation controller with your ExampleViewController .

Then you need to embed your first controller with navigation controller. To add navigation controller -

Answer 2

Have you add StoryBoard ID in storyboard? If not,add the identifier( ImageCollectionVC ) to the storyboard.

Then try this:

UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ImageCollectionVC") as! ImageCollectionViewController