如何在没有情节提要的情况下以编程方式实例化视图控制器

Question

Is there a way to instantiate a view controller programatically without using storyboard identifier. I want to push CNContactPickerController into my root view controller .

let controller = CNContactPickerViewController()
controller.delegate = self
navigationController?.present(controller, animated: true, completion: nil)

i did this but in contactPicker (delegate) i push a VC from storyboard where i save what info i want from that specific contact. The problem: when i pop the last view controller i want to go on the CNConctactPickerControllerView but i go on the first view controller i tried with dismiss but nothing happens..

Answer 1

The problem with doing this is that NONE of the UI for your view controller is created. What you are doing is simply instantiating an instance of the class. None of the corresponding UI is created, also your IBOutlet s will be nil.

You have 2 options, either you use Interface builder and instantiate from the Nib or Storyboard, or you create ALL your UI manually in code.

For the sake of resuability you could create a static method on CNContactPickerViewController to handle the storyboard instantiation for you. See the following:

class CBContactPickerViewController: UIViewController {

    static func fromStoryboard() -> CNContactPickerViewController {
        return UIStoryboard(name: "foobar", bundle: nil).instantiateViewController(identifier: "CNContactPickerViewController") as! CNContactPickerViewController
    }
}

You can then utilise this as follows:

self.present(viewController: CNContactPickerViewController.fromStoryboard(), animated: true, completion: nil)