ios - Disable the interactive dismissal of presented view controller

Question

iOS 13 introduces a new design of modalPresentationStyle .pageSheet (and its sibling .formSheet) for modally presented view controllers…

…and we can dismiss these sheets by sliding the presented view controller down (interactive dismissal). Although the new "pull-to-dismiss" feature is pretty useful, it may not always be desirable.

THE QUESTION: How can we turn the interactive dismissal off? - Bear in mind we keep the presentation style the same.

Answer 1

Option 1:

viewController.isModalInPresentation = true

(Disabled interactive .pageSheet dismissal acts like this.)

• Since the iOS 13, UIViewController contains a new property called isModalInPresentation which must be set to true to prevent the interactive dismissal.
• It basically ignores events outside the view controller's bounds. Bear that in mind if you are using not only the automatic style but also presentation styles like .popover etc.
• This property is false by default.

From the official docs: If true, UIKit ignores events outside the view controller's bounds and prevents the interactive dismissal of the view controller while it is onscreen.

---

Option 2:

func presentationControllerShouldDismiss(_ presentationController: UIPresentationController) -> Bool {
    return false
}

• Since the iOS 13, UIAdaptivePresentationControllerDelegate contains a new method called presentationControllerShouldDismiss.
• This method is called only if the presented view controller is not dismissed programmatically and its isModalInPresentation property is set to false.

Tip: Don't forget to assign presentationController's delegate.