Swift 3 - 关闭当前的 ViewController 并打开新的 ViewController

Question

I've gone through a tad amount of SO posts about this but none of them clearly state how to get this done in Swift 3.

Simply put, I need to close the current view that is displayed and open a new view controller. Such that the only view controller open would be the 2nd VC

This is the code I tried using, but when I try this the view controller gets closed without the rest of the code getting executed

//Close current VC
self.dismiss(animated: true, completion: nil)

//Open the new VC
let mainStoryboard: UIStoryboard = UIStoryboard(name:"Main",bundle:Bundle.main)
let secondViewController: SecondViewController = mainStoryboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController
self.present(secondViewController, animated: true, completion: nil)

Can someone help me out? I just need a simple transition from 1st VC to 2nd VC and close the 1st VC.

Answer 1

The problem is, that "self" can not present the new ViewController since it is the ViewController that is getting dismissed.

You could try calling self.presentingViewController?.present(secondViewController, animated: true, completion: nil)

Answer 2

After spend full day i got a solution on Apple' developer website (on this link )

let storyboard = UIStoryboard(name: "Main", bundle: nil)
          let secondVC = storyboard.instantiateViewController(identifier: "second_view_controller")

          secondVC.modalPresentationStyle = .fullScreen
          secondVC.modalTransitionStyle = .crossDissolve

          present(secondVC, animated: true, completion: nil)

Answer 3

If you presented that view controller from some view controller or it is the viewcontroller from navigation or tab viewcontroller, then try to get last visible view controller, code is in this link

Get the current displaying UIViewController on the screen in AppDelegate.m

or else use this code (I have copied from that link)

public extension UIWindow {
    public var visibleViewController: UIViewController? {
        return UIWindow.getVisibleViewControllerFrom(self.rootViewController)
    }

    public static func getVisibleViewControllerFrom(_ vc: UIViewController?) -> UIViewController? {
        if let nc = vc as? UINavigationController {
            return UIWindow.getVisibleViewControllerFrom(nc.visibleViewController)
        } else if let tc = vc as? UITabBarController {
            return UIWindow.getVisibleViewControllerFrom(tc.selectedViewController)
        } else {
            if let pvc = vc?.presentedViewController {
                return UIWindow.getVisibleViewControllerFrom(pvc)
            } else {
                return vc
            }
        }
    }
}

Then present your viewcontroller from that visibleViewController -

//Close current VC

self.dismiss(animated: true, completion: nil)

//Open the new VC

let mainStoryboard: UIStoryboard = UIStoryboard(name:"Main",bundle:Bundle.main)
let secondViewController: SecondViewController = mainStoryboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController
window?.visibleViewController?.present(secondViewController, animated: true, completion: nil)

If your view controller is the root view controller, then set it to root view controller

if let delegate = UIApplication.shared.delegate as? AppDelegate {
     delegate.window?.rootViewController = secondViewController
 }