Presenting the new controller programatically in ios swift only displaying blank screen - ios

Question

I am developing a simple IOS application using swift. In my application I need to open new controller programatically from another controller. So I added another scene to the storyboard.
This is the screenshot
Then I added a new class for new controller which is inheriting from the UIViewController. This is the code for new controller
import UIKit
class ReplayController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}
Then, I tried to open the new controller view (ReplayController) from the main controller like this in code.
func gameOver()
{
let replayController = ReplayController()
present(replayController, animated: true, completion: nil)
}
When I call that function, it just pops up the blank screen. Nothing appear on the screen. What is wrong and how can I solve it?

Answer 1

In your Storyboard file, ensure the ReplayController has its 'File's Owner' set to your ReplayController class. Then set the Storyboard ID like below:
Then you can load it like so:
let replay = storyboard?.instantiateViewController(withIdentifier: "ReplayController") as! ReplayController
self.present(replay, animated: true, completion: nil)

Answer 2

You have to reference it with id in storyboard
let replayController = self.storyboard?.instantiateViewController(withIdentifier: "replayControllerID") as! ReplayController
present(replayController, animated: true, completion: nil)
as this line only
let replayController = ReplayController()
doesn't load the xib or storyboard object associated with the VC

Answer 3

When you design your view controllers in storyboard, you need to programatically create them using the method instantiateViewController of class UIStoryboard to access it along with all the outlets.
Before that, you need to set the Storyboard ID of the respective view controller in your storyboard like this:
And then present it:
func gameOver() {
if let myVC = storyboard?.instantiateViewController(withIdentifier: "ViewController") {
self.present(myVC, animated: true, completion: nil)
}
}