I have system \"NavigationViewController -> MyViewController\", and I programmatically want to present MyViewController inside a third view controller. The problem is that I
SWIFT 3
let VC1 = self.storyboard!.instantiateViewController(withIdentifier: "MyViewController") as! MyViewController
let navController = UINavigationController(rootViewController: VC1)
self.present(navController, animated:true, completion: nil)
The accepted answer is great. This is not answer, but just an illustration of the issue.
I present a viewController like this:
inside vc1:
func showVC2() {
if let navController = self.navigationController{
navController.present(vc2, animated: true)
}
}
inside vc2:
func returnFromVC2() {
if let navController = self.navigationController {
navController.popViewController(animated: true)
}else{
print("navigationController is nil") <-- I was reaching here!
}
}
As 'stefandouganhyde' has said: "it is not contained by your UINavigationController or any other"
new solution:
func returnFromVC2() {
dismiss(animated: true, completion: nil)
}
Calling presentViewController
presents the view controller modally, outside the existing navigation stack; it is not contained by your UINavigationController or any other. If you want your new view controller to have a navigation bar, you have two main options:
Option 1. Push the new view controller onto your existing navigation stack, rather than presenting it modally:
let VC1 = self.storyboard!.instantiateViewControllerWithIdentifier("MyViewController") as! ViewController
self.navigationController!.pushViewController(VC1, animated: true)
Option 2. Embed your new view controller into a new navigation controller and present the new navigation controller modally:
let VC1 = self.storyboard!.instantiateViewControllerWithIdentifier("MyViewController") as! ViewController
let navController = UINavigationController(rootViewController: VC1) // Creating a navigation controller with VC1 at the root of the navigation stack.
self.present(navController, animated:true, completion: nil)
Bear in mind that this option won't automatically include a "back" button. You'll have to build in a close mechanism yourself.
Which one is best for you is a human interface design question, but it's normally clear what makes the most sense.
My navigation bar was not showing, so I have used the following method in Swift 2 iOS 9
let viewController = self.storyboard?.instantiateViewControllerWithIdentifier("Dashboard") as! Dashboard
// Creating a navigation controller with viewController at the root of the navigation stack.
let navController = UINavigationController(rootViewController: viewController)
self.presentViewController(navController, animated:true, completion: nil)
I used an extension to UIViewController and a struct to make sure that my current view is presented from the favourites
1.Struct for a global Bool
struct PresentedFromFavourites {
static var comingFromFav = false}
2.UIVeiwController extension: presented modally as in the second option by "stefandouganhyde - Option 2 " and solving the back
extension UIViewController {
func returnToFavourites()
{
// you return to the storyboard wanted by changing the name
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let mainNavigationController = storyBoard.instantiateViewController(withIdentifier: "HomeNav") as! UINavigationController
// Set animated to false
let favViewController = storyBoard.instantiateViewController(withIdentifier: "Favourites")
self.present(mainNavigationController, animated: false, completion: {
mainNavigationController.pushViewController(favViewController, animated: false)
})
}
// call this function in viewDidLoad()
//
func addBackToFavouritesButton()
{
if PresentedFromFavourites.comingFromFav
{
//Create a button
// I found this good for most size classes
let buttonHeight = (self.navigationController?.navigationBar.frame.size.height)! - 15
let rect = CGRect(x: 2, y: 8, width: buttonHeight, height: buttonHeight)
let aButton = UIButton(frame: rect)
// Down a back arrow image from icon8 for free and add it to your image assets
aButton.setImage(#imageLiteral(resourceName: "backArrow"), for: .normal)
aButton.backgroundColor = UIColor.clear
aButton.addTarget(self, action:#selector(self.returnToFavourites), for: .touchUpInside)
self.navigationController?.navigationBar.addSubview(aButton)
PresentedFromFavourites.comingFromFav = false
}
}}