Present and dismiss last UIViewController

Question

I am building an app to present UIViewController and dismiss the current UIViewController at the same time.

Currently I'm in viewcontroller1 and i want to present viewcontroller2 as main controller and dismiss viewcontroller1 to remove it from memory, so viewcontroller2 will be the main controller after presenting and there is no viewcontroller1 in stack.

I've tried :

let controller = storyboard?.instantiateViewControllerWithIdentifier("controller2") as! viewcontroller2
controller.modalTransitionStyle = UIModalTransitionStyle.CrossDissolve

self.dismissViewControllerAnimated(false) { () -> Void in

    self.presentViewController(controller, animated: false, completion: nil)

}

But it gave me : 0x7fee28711900> whose view is not in the window hierarchy!

Is there is a way to do that ?

Answer 1

If you want to replace a UIViewController entirely, you should do this:

 UIApplication.sharedApplication().keyWindow?.rootViewController = newController

This however will not cross-dissolve.

If you need to cross, you'll just have to present the new view controller "over" the old one, or follow the advice in this post and re-write it Swift:

https://stackoverflow.com/a/8248284/233602