DestinationViewController Segue and UINavigationController swift

问题

So I have a prepareForSegue method like this:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "fromEventTableToAddEvent" {

        let addEventViewController: AddEventViewController = segue.destinationViewController as! AddEventViewController

        addEventViewController.newTagArray = newTagArray

    }
}

However, at runtime the app crashes and logs spit out this message:

Could not cast value of type 'UINavigationController'

The error comes because the addEventController is embedded in a navigation controller, however I'm not sure how I would set up the segue so that the destinationViewController is set to the NavigationController, but also allow me to pass variables in the prepareForSegue method to the addEventController

So how would I do this using Swift?

I extremely appreciate your help and time you may offer in response. It helps alot

回答1:

You only need to access the navigation controller's topViewController, which will be the AddEventViewController. Here is the code:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "fromEventTableToAddEvent" {

        let nav = segue.destinationViewController as! UINavigationController
        let addEventViewController = nav.topViewController as! AddEventViewController

        addEventViewController.newTagArray = newTagArray

    }
}

来源：https://stackoverflow.com/questions/28573635/destinationviewcontroller-segue-and-uinavigationcontroller-swift

标签

ios

swift

segue