如何从包含在一个 VC 中的一个 VC 转换为将包含在与另一个相同的 VC 中的新 VC？

Question

When the app launches you begin on the ViewController (the one in the middle). From there I add the VC on the right. When a user taps a button which is on this VC I want that view to go away (which I currently accomplish by just changing its frame to 900) and in its place comes the VC on the Left.

All the things I have tried failed given that I am so unclear on how to do this.

How do I make this kind of functionality work?

Answer 1

You can do this by:

        if let ViewController2 = segue.destination as? ViewController2 {        
            //here...   
        } else if let viewcontroller = segue.destination as? ViewController1 {
            //here..
        }

Answer 2

Assuming you have reference to the container view you can hide and unhide Views but the RightViewController on the right must communicate to the main middle MiddleViewController

Here you can use Protocols to communicate between the two, have a look into https://medium.com/@nimjea/delegation-pattern-in-swift-4-2-f6aca61f4bf5 for more details.

When the RightViewController tells/delegates the MiddleViewController that the button is tapped

you can just

self.rightContainerView.isHidden = true
self.leftContainerView.isHidden = left