It's easier to show you a drawing and then explain.
Dashboard Storyboard
I have 2 separate UIViewControllers (i've included just one in the drawing, the other is irrelevant) embedded in container view called ContainerViewController.
Post Storyboard
NewPostViewController shows a UIButton that presents TextPostViewController. As you can see, all of them are embedded in UINavigationControllers. Now, once the completion block of the new post is being called, I have to present the ContainerViewController and it needs to handle it's own logic. The problem is that it's embedded in UINavigationController and once I present it, the UITaBbar is hidden.
I tried to do this:
self.performSegue(withIdentifier: "TextPostToNavContainerVC", sender: nil)
The transition is successful but I'm losing the UITabBar, even though in the DashboardViewController and the ContainerViewController I called:
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
tabBarController?.tabBar.isHidden = false
}
What am I doing wrong or is there are better way to do that?
You should instantiate the tab bar controller. not the view controller.
Imagine you're putting a initial view controller ahead of your tab bar controller. Making your tab bar not being pushed
If I undestand it correctly.
You are doing this
Segue connect to a view controller
But you should actually do this Segue connected to a tab bar controller
You can try to add it as a child to control it's frame like this
let textPost = self.storyboard?.instantiateViewController(withIdentifier: "containerID") as! TextPostToNavContainerVC
textPost.view.frame = CGRect(x:20,y:0,width:self.view.frame.width,height:self.view.frame.height-50)
self.view.addSubview(nvc.view)
self.addChildViewController(textPost)
textPost.didMove(toParentViewController: self)
Related
I have a storyboard with two view controllers. First one, VC_1, has one button that opens 2nd one - VC_2.
VC_2 also has a button that opens VC_1.
Both controllers have almost identical code:
class VC_1: UIViewController
{
override func viewDidLoad()
{
super.viewDidLoad()
print(“VC_1 loaded")
}
override func viewDidAppear(_ animated: Bool){ print(“VC_1 appeared") }
override func viewDidDisappear(_ animated: Bool){ print(“VC_1 disappeared") }
#IBAction func btnShowVC_2(_ sender: UIButton)
{
let storyboard = UIStoryboard(name: "Main", bundle: nil)
secondVC = storyboard.instantiateViewController(identifier: “VC_2”)
secondVC.modalPresentationStyle = .fullScreen
show(secondVC, sender: self)
}
}
The difference is only in "VC_2" instead of "VC_1" in the 2nd controller code.
I have seen this View Controller creation code in Apple documentation and many other examples around the Internet.
When I press the button on the VC_1, I see in the debug window, that VC_2 is loaded and appeared, and VC_1 is disappeared. And same, of course, happens when I press the button on VC_2 - it disappears, and VC_1 is loaded again.
My questions are:
what happens with View Controller object after "viewDidDisappear" has been called? Does it really disappear from memory, or "disappear" only means "you cannot see it on the screen?". I do not see "viewDidUnload" in the documentation...
I suppose that "viewDidLoad" means that new View Controller object was created in memory. Is there any way to load the View Controller object only once, and then hide and show it without causing "viewDidLoad" to be called? I tried to do it with global variable "secondVC" but got "Application tried to present modally an active controller" error.
viewDidDisappear: called after the view is removed from the windows’
view hierarchy. No, View controller object just left the view property. By the way the amount of memory used by view controllers is negligible. So dont think about too much. If you want to catch when Your View controller object release from the memory put
deinit { print("vc deallocated") }
viewDidUnload, it has been deprecated since the iOS
6, which used to do some final cleaning.
Partly true. Keep in mind ViewDidload called one time for the life cycle of view controller. There is a method called before viewdidload but this is not related with your question.
In addition to "There is a method before viewdidload" -> loadView( ) is a method managed by the viewController. The viewController calls it when its current view is nil. loadView( ) basically takes a view (that you create) and sets it to the viewController’s view (superview).
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 have a tab bar app where one of the views is a UITableViewController containing static cells as content with 1 section and 1 row.
I want the Large Title to be set to "Always," so I made the selection on the storyboard and the title was large on the simulator. Now when the user taps "Start Chat," the app will segue to the Virtual Assistant View Controller, where the Large Title is set to "Never" on the storyboard. Now the problem is that when the user segues back to the previous view controller with the "Start Chat" table view cell, the title is not large anymore.
It is interesting that when I set the table view to be scrollable, the title becomes large again upon dragging down the table view. I made sure the navigation bar on the Navigation Controller storyboard is checked with the "Prefers Large Titles." I am using Xcode 11, and this was not a problem when using Xcode 10.
I tried creating a custom class for the view with the start chat button and this code did not work in making the title large from a segue back:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.navigationItem.largeTitleDisplayMode = .always
navigationController?.navigationBar.prefersLargeTitles = true
What else could I do? Any help will be greatly appreciated!
I'd use willMove(toParent:) to change the title back before the segue is performed.
override func willMove(toParent parent: UIViewController?) {
navigationController?.navigationItem.largeTitleDisplayMode = .always
navigationController?.navigationBar.prefersLargeTitles = true
}
Set the properties when setting up the UINavigationController, before presenting it. If you already presented the navigation controller, try doing this to force-update the navigation bar:
navigationController?.navigationItem.prompt = ""
navigationController?.navigationItem.prompt = nil
I took this workaround from this question.
In your particular case, it would be better to subclass the navigation controller and set those properties in its viewDidLoad method, so its properties (largeTitleDisplayMode and prefersLargeTitles) are set in a self-contained code.
I have a CollectionView running in my project and the collectionViewController connected to another tableview using custom segue as follows.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
selectedMenuItem = indexPath.row
//Present new view controller
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main",bundle: nil)
var destViewController : UINavigationController
switch (indexPath.row) {
case 0:
destViewController = mainStoryboard.instantiateViewControllerWithIdentifier("NewTableView") as UINavigationController
break
default:
destViewController = mainStoryboard.instantiateViewControllerWithIdentifier("NewTableView") as UINavigationController
break
}
self.presentViewController(destViewController, animated: true, completion: nil)
}
above code populating my NewTableview successfully but the tableview missing navigation bar completely.
so far my tries as follow...
i embedded new navigationController to collectionView results remain unchanged.
i embedded new navigationController to NewTableView results remain unchanged.
i tried unwind segue method using custom navigation button action method.so i insert the navigation bar item and button to the view and Method works,but it works strangly when navigation bar button pressed it takes me to my main collection view controller thats what i what.but i have another back button appears in collection view rowindex item name on it.when i pressed the button it take me back to the NewTableView its like looping through.
i don't know what i am missing (any delegate method).and i noticed the newTableView data loading from the bottom with animation...
i wondering is there any way to put a navigation programmatically with back button behaviour...
Thanks in Advance.....
You'll have to instantiate the navigation controller, not the actual view controller from your storyboard. So instead of instantiating NewTableView (the view controller you want embedded in the navigation controller), you should add an identifier to your UINavigationController so that it will be instantiated instead of the view controller itself.
Just imagine that you reuse the NewTableView controller which does not require a navigation controller as its root, how would iOS be aware of that ? So add an identifier to your hosting UINavigationController and instantiate that. The navigation controller has a root dependency on the rootViewController which will be shown by default, so you only need to display the UINavigationController and the NewTableView controller will be shown based on the dependency it has with the navigation controller.
i'm fairly new to swift and having some difficulty with unwind segues in a master detail application.
the unwind seems to work fine dismissing my popovers on the iPhone, however when i try the same thing on the iPad, the popover remains.
If i add a dismissViewControllerAnimated to the presenting viewController's unwind handling action, then the iPad version works fine and dismisses the popover, however the iPhone version dismisses the popover and then dismisses the view that presented the popover. i.e. dismisses two views.
I have worked out that the problem is that popover's are automatically dismissed with an unwind when presented modally such as on an iPhone. However when presented as true popovers they don't dismiss with an unwind segue. Could somebody help me figure out how to manage both cases so that only the popover will be dismissed. Thank you very much in advance.
Okay. after a long time working on this i managed to come up with a solution. i used a popoverpresentationcontroller and declared the presenting controller as the delegate. by then adding an additional function forcing the iPhone to use the popover in lieu of the modal presentation, the presentation and dismissal is consistent for the iPhone and iPad. the code is below. I just used a generic UIViewController in the if let vc statement so that I could use this with a popover that's imbedded in a navigation controller also.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let identifier = segue.identifier {
switch identifier {
case "My Segue Identifier" :
if let vc = segue.destinationViewController as? UIViewController {
if let ppc = vc.popoverPresentationController {
ppc.delegate = self
}
}
default: break
}
}
}
additionally you need to add the following function to prevent the modal presentation on the iPhone:
func adaptivePresentationStyleForPresentationController (controller:UIPresentationController)-> UIModalPresentationStyle {
return UIModalPresentationStyle.None
}