I have two storyboard (Main and SB2)
I have one view controller in storyboard in Main and one in SB2
I perform
let SB2 = UIStoryboard(name: "SB2", bundle:nil)
let vc : UIViewController = self.SB2.instantiateViewControllerWithIdentifier("VC2")
self.showViewController(vc, sender: self)
After the second viewcontroller loads and this command is run, it prints nil:
print(self.navigationController) // prints nil
In SB2 (second storyboard) I clicked on the viewcontroller (VC2) and then clicked on Editor > Embed In > Navigation Controller. This placed a navigation controller with the storyboard and the root view controller is VC2. I triple checked this. The first sign of it being connected was the gray navigation bar on top. The second being that there is segue connecting the navigation controller to VC2 and the last place I could have checked is in the navigation controller utilities.
I am thinking that maybe I shouldn't transition from VC1 to VC2 directly but rather VC1 to NavigationController however I don't know how to do this or if its even possible.
I don't know when sb2 prints nil when in face a navigation controller is connected to it. Any help is appreciated.
You need to push the view controller (VC2) on to the navigation controller.
let SB2 = UIStoryboard(name: "SB2", bundle:nil)v
let nvc = SB2.instantiateViewControllerWithIdentifier("NVC") as! UINavigationController
let vc : UIViewController = self.SB2.instantiateViewControllerWithIdentifier("VC2")
nvc.pushViewController(vc, animated: true)
Then in your view controller try calling
self.navigationController
In your storyboard,
select the initial ViewController. With this view controller selected, choose the menu item
Editor -> Embed In -> Navigation Controller
Related
I created View Controllers and I want to add Navigation Controller now. I tried embed-in Navigation Controller to My DetailViewContoller(colorful View Controller) but I got an error. main.storyboard, error. How can I add Navigation Controller ?
In order to set view controller as navigation controller, you can set it programmatically by calling this function in appdelegate or scenedelegate or any point.
func setNavigationController() {
var viewController: UIViewController
let storyboard = UIStoryboard(name: "myStoryboardName", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier: "myVCID")
let rootViewController = UINavigationController(rootViewController: viewController)
rootViewController.setNavigationBarHidden(true, animated: false)
self.view.window?.rootViewController = rootViewController
}
If you want to set navigation controller through storyboard, then you have to first add navigation controller and set is root view controller to the controller you want to make it navigation controller.
My app has a TabBarController. Each tabBarItem relates to a ViewController embedded in a NavigationController.
When in first tabBarItem and selecting another tabBarItem I want to do some stuff before moving to the selected ViewController. Therefore I created a class for my tabBarController and made it UITabBarControllerDelegate.
What I want to do is present an alert with two buttons; button A cancels the move to the selected viewController and button B lets the move happen.
My problem is that when button B is pressed, I want to popToRootViewController. I gave the navigationController a storyboardID and tried to instantiate it like shown below.
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
if let alert = self.storyboard?.instantiateViewController(withIdentifier: "ActiveSessionWarningAlert") as? ActiveSessionWarningAlert {
alert.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
alert.modalTransitionStyle = UIModalTransitionStyle.flipHorizontal
let alertWasDismissed: (Bool) -> Void = { userWantsToMoveToSelectedViewController in
if userWantsToMoveToSelectedViewController {
if let navContr = self.storyboard?.instantiateViewController(withIdentifier: "firstNavContr") as? UINavigationController {
navContr.popToRootViewController(animated: true)
}
tabBarController.selectedViewController = viewController
}
}
alert.alertWasDismissed = alertWasDismissed
self.present(alert, animated: true, completion: nil)
}
return false
}
Everything works as expected, but the popToRootViewController doesn't seem to occur; when selecting the first tabBarItem again the same viewController that was 'active' when we left the item is still showing.
I checked so that the viewController I want to pop is actually in the navigation stack and that the navContr != nil.
What am I missing?
You don't say so, but I'm assuming that the alertWasDismissed closure you pass to your alert view controller gets invoked when the user dismisses the alert.
The problem with your closure is this bit:
if let navContr = self.storyboard?.instantiateViewController(withIdentifier: "firstNavContr") as? UINavigationController
Any time you call instantiateViewController(withIdentifier:), you are creating a brand new, never before seen instance of a view controller (a navigation controller in this case.) That navigation controller has nothing to do with the one that belongs to the current tab that you are trying to dismiss. It doesn't have anything in it's navigation stack other than the root view controller that is defined in the storyboard.
What you need to do is find the navigation controller of the current tab in your tab bar controller's tabBarController(_:shouldSelect:) method, and pass that navigation controller to your alertWasDismissed closure.
At the time the tabBarController(_:shouldSelect:) method is called, the tab bar controller's selectedViewController should contain the current view controller. Replace the line above with:
if let navContr = tabBarController.selectedViewController? as? UINavigationController {}
That should work.
Having some trouble permanently moving one from view controller to another. The normal segues seem to all have a 'go back' option.
I know I can imbed the VC in a navigation controller and create a custom segue which rewrites the hierarchy/changes root VC
class ReplaceSegue: UIStoryboardSegue {
override func perform() {
source.navigationController?.setViewControllers([self.destination], animated: false)
}
}
But I want to avoid a navigation controller as it will confuse things when I add a SWRevealViewController later.
Can/Should I change the storyboard VC (outside of AppDelegate that is)?
Thanks - apologies if this is a 'beginner' question
You can either change rootViewController of your main window:
self.window.rootViewController = vc
or you can just simply set vc's modalPresentationStyle to fullscreen (this doesn't have a "go back" option by itself, only you can dismiss it calling dismiss)
let vc = UIViewController()
vc.modalPresentationStyle = .fullScreen
or from storyboard change it's presentation style to fullscreen.
I am trying to embed my view controller into a navigation view controller so i get the navigation bar and all the other stuff like back buttons. I want to do it programmatically.
It is done like this:
// example ViewController
let myVC = UIViewController()
// create the NavigationController with my VC as root
let navCon = UINavigationController(rootViewController: myVC)
i have 2 view controllers then tab bar controller connected to 3 navigation controller , each navigation connected to multiple views .
The point that from one of these views that is connected to one of navigation controllers , i want to back again to the start screen , it good by this 2 lines :
let loginViewController = self.storyboard?.instantiateViewController(withIdentifier: "LoginViewController")
UIApplication.shared.keyWindow?.rootViewController = loginViewController
but after i do this and want to navigate again to the tab bar its disappeared from the view . I used this to navigate to tab bar :
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let viewTabController = self.storyboard?.instantiateViewController(withIdentifier :"MainTabBarController") as! MainTabBarController
viewTabController.selectedIndex = 1
appDelegate.window?.rootViewController = viewTabController
Thanks in advance.
When you use instantiateViewController you are making new instances of view controllers in memory while there is no need in your case , you have created them before. so you can dissmis your tabBar and go back to first screen like this (initial viewcontroller must be embeded into a navigation controller) :
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let navigationController = appDelegate.window?.rootViewController as! UINavigationController
navigationController.dismiss(animated: true, completion: nil)
for bringing back tabBar you can either save its instance in your app delegate and present it or use a storyboard segue to present it modally
:)