无法使用parentViewController（Swift）关闭viewController

Question

I am trying to dismiss a view controller like so:

func cropViewController(cropViewController: TOCropViewController!, didFinishCancelled cancelled: Bool) {

        if let vc = cropViewController.parentViewController {
            print("has controller")
            vc.dismissViewControllerAnimated(true, completion: nil)
        }

    }

TOCropViewController is a subclass of UIViewController. Sometimes I present it from self and sometimes from picker (a UIImagePicker controller). I'm trying to dismiss it by accessing the parent however none of the code in the if statement is executing. It can't seem to find the controller. Any ideas what I might be doing wrong here? Any help would be really appreciated! thanks!

Answer 1

A presented view controller doesn't have a parent, it has a presenter. This can be confusing.

You can send dismissViewControllerAnimated(_:completion:) to the presented view controller to have it dismiss itself:

If you call this method on the presented view controller itself, UIKit asks the presenting view controller to handle the dismissal.

Or you can ask the view controller for its presenting view controller, and ask the presenter to dismiss the presented:

    if let vc = cropViewController.presentingViewController {
        print("has presenter")
        vc.dismissViewControllerAnimated(true, completion: nil)
    }