How to dismiss own view controller and present another view controller in a button tap?

Question

Let\'s say I have 3 view controller labeled \"A\",\"B\" and \"C\". Right now, \"A\" is the rootViewController of the window and it presents \"B\" modally when a button is ta

Answer 1

It seems that it is not possible to go from B to C without showing A briefly, which looks unprofessional. However, you can put a black subview over top of A until you've animated to C.

In Swift 3:

class A : UIViewController {
    ...
    func showB() {
        // Adding the black view before dismissing B does not work;
        // the view is not displayed.
        let black = UIView()
        black.backgroundColor = UIColor.black
        black.frame = self.view.bounds // assumes A is not zoomed

        let b = B()
        self.present(b, animated:true, completion: {
            self.view.addSubview(black)
        })

        // Note: self.present() will start the animation,
        // then b.imDone will be set.  It is done here for
        // clarity of what happens next, as if it were all
        // one function.
        b.imDone = {
            b.dismiss(animated:false, completion: {
                self.present(C(), animated:true, completion: {
                    black?.removeFromSuperview()
                })
            })
        }
    }
}

class B : UIViewController {
    var imDone : (() -> Void)?
    ...
    func f()
    {
        imDone?()
    }
    ...
}

class C : UIViewController
{
    ...
}