Swift: Multiple Inheritance from classes Error UIViewController and UIIMagePickerController

Question

I manually added two additional controllers (UINavigationControllerDelegate & UIImagePickerController) to a UIViewController and I am receiving an error after adding the UIImagePickerController that says,

Multiple inheritance from classes UIViewController and UIImagePickerController

I'm not sure how to interpret and fix that right now.

As a result of this error, I'm also seeing one when I use the image.delegate method and set it equal to self

Type ViewController does not conform to protocol UIImagePickerControllerDelegate

Code:

class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerController {

    @IBAction func pickImage(sender: UIButton) {

        var image = UIImagePickerController()
        image.delegate = self
        image.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        image.allowsEditing = false

        self.presentViewController(image, animated: true, completion: nil)


    }

Answer 1

You should have UIImagePickerControllerDelegate, not UIPickerViewController in your first line. The system thinks that you are trying to have your controller inherit from both UIViewController and UIImagePickerController which is not allowed.

Answer 2

I think it is that swift doesn't allow multiple inheritance, protocols are essentially what other languages call interfaces and they serve the same purpose - to allow a safe and limited form of multiple inheritance. Try to change it like this. See more from here and protocol.

class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate