I am concerned about NavigationViewController stack in the sense that apple documentation says that "A navigation controller object manages the currently displayed screens using the navigation stack, which is represented by an array of view controllers." And what about another NavigationController attached to the topViewController? Is it in navigation stack? Or there are two navigation stacks? enter image description here and so at the end what viewController will the top of this construction if we will call
func application(_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions:
[UIApplicationLaunchOptionsKey: Any]?) -> Bool {
guard let navController = window?.rootViewController as?
UINavigationController,
let viewController = navController.topViewController else {
return true
}
Related
I have created TableViewController by xib not on storyboard. I have view controller which loads by default. Now I want that TableViewController as root controller. Thanks in advance.
1 first register you xib in particular viewController in which you want to load.
by register.nibLod
2 then in AppDelegate in - didFinish method make your that particular viewController as rootviewcontroller.
You can do like this.
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
window = UIWindow(frame: UIScreen.main.bounds)
let navigationController: UINavigationController = UINavigationController(rootViewController: YourViewController()) //where YourViewController is name of viewController which you want to use as rootViewController
self.window?.rootViewController = navigationController
self.window?.makeKeyAndVisible()
return true
}
I changed my Navigation Controller to Tab Bar Controller, then I wanted to compile the app. But it does not load my managedContext anymore.
This is my launching code when I load the app:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
guard let navController = window?.rootViewController as? UINavigationController,
let viewController = navController.topViewController as? ViewController else {
return true
}
viewController.managedContext = coreDataStack.managedContext
// Override point for customization after application launch.
return true
}
Therefore I tried to edit the code like this:
Edit:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateInitialViewController()
//let controller = storyboard.instantiateViewController(withIdentifier: "TabBarVC")
self.window?.rootViewController = controller
guard let tabController = window?.rootViewController as? UITabBarController,
let navController = tabController.viewControllers![0] as? UINavigationController,
let viewController = navController.topViewController as? ViewController else {
return true
}
// Version that works for UINavigationCOntroller
// guard let navController = window?.rootViewController as? UINavigationController,
// let viewController = navController.topViewController as? ViewController else {
// return true
// }
viewController.managedContext = coreDataStack.managedContext
// Override point for customization after application launch.
return true
}
I changed the code, but I still can not load managedContext, and it returns nil when I want to use it in ViewController, I also set the initial Viewcontroller to the tabBarController.
Set rootviewcontroller for your window first and then right your logic afterwards.
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
let storyboard = UIStoryboard(<StoryboardName>, bundle: nil)
let controller = storyboard.initializeInitialViewController()
window.rootViewController = controller
guard let navController = window?.rootViewController as? UITabBarController,
let viewController = navController.moreNavigationController as? ViewController else {
return true
}
viewController.managedContext = coreDataStack.managedContext
// Override point for customization after application launch.
return
I have created a Tab Bar App. On the first item, is a Split View Controller with a Master and Detail. When running the app, I can see the tab bar on the page however, it's showing my Detail page. Why is it not defaulting to the Master page?
I have researched some answers but no luck.
SplitViewController.swift
import UIKit
class SplitViewController: UISplitViewController,
UISplitViewControllerDelegate {
override func viewDidLoad() {
self.delegate = self
self.preferredDisplayMode = .allVisible
}
func splitViewController(
_ splitViewController: UISplitViewController,
collapseSecondary secondaryViewController: UIViewController,
onto primaryViewController: UIViewController) -> Bool {
// Return true to prevent UIKit from applying its default behavior
return true
}
Just for reference in case someone bumps into the same problem.
I had to use my Master-Detail SplitViewController app (without the tab bar) and do the following:
Add a Tab Bar Controller.
Connect the binding from Tab Bar Controller to the Split View Controller, as a view controller.
Revise AppDelegate.swift
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
let tabBarViewController = self.window!.rootViewController as! UITabBarController
print(tabBarViewController.viewControllers?.count)
var splitViewController:UISplitViewController? = nil
for viewController in tabBarViewController.viewControllers! {
if viewController.title == "Master" {
splitViewController = viewController as? UISplitViewController
}
}
return true
}
Set Tab Bar Controller to be the Initial View Controller.
Hope this helps. Thanks!
My root view is a tab bar controller, I would like to open the app on a specific tab when a certain notification is received. If I use presentViewController the tab bar disappears. Is there a specific way to do this?
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
let myTabBar = self.window.rootViewController as! UITabBarController // Getting Tab Bar
myTabBar.selectedIndex = 2 //Selecting tab here
return true
}
I know the way to pass coreDataStack to the viewController with navigation controller embedded by this way.
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
let navigationController = window!.rootViewController as! UINavigationController
let viewController = navigationController.topViewController as! ViewController
viewController.coreDataStack = coreDataStack
return true
}
I want to pass the coreDataStack to my viewController without the navigation controller,
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let viewController = mainStoryboard.instantiateViewControllerWithIdentifier("Home") as! Home
viewController.coreDataStack = coreDataStack
return true
}
However, the coreDataStack in the viewController found to be nil.
How can I do it?
Your code is creating a new instance of the view controller, not referencing the existing instance. You should be able to use this:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
let viewController = window!.rootViewController as! ViewController
viewController.coreDataStack = coreDataStack
return true
}