Using Swift 1.1 and Xcode 6.2.
I have a UIStoryboard containing a singular, custom UIViewController subclass. On it, I have an #IBOutlet connection of type UIView from that controller to a UIView subclass on the storyboard. I also have similar outlets for subviews of that view. See figure A.
But at run time, these properties are nil (Figure B). Even though I have assured I've connected the outlets in Interface Builder.
Thoughts:
Is it possible that because I am using a subclass of a subclass something messes up with the initialization? I am not overriding any initializers
awakeFromNib: is not getting called for some reason
Maybe it doesn't connecting to subviews on subviews
Things I have tried:
Matching #IBOutlet and storyboard item types exactly (instead of UIView)
Deleting property and outlet and re-added them
Figure A*
Figure B
*The obscured code in Figure A is:
#IBOutlet private var annotationOptionsView: UIView!
#IBOutlet private var arrivingLeavingSwitch: UISegmentedControl!
Thank you.
Typically this happens because your view controller hasn't loaded its view hierarchy yet. A view controller only loads its view hierarchy when something sends it the view message. The system does this when it is time to actually put the view hierarchy on the screen, which happens after things like prepareForSegue:sender: and viewWillAppear: have returned.
Since your VC hasn't loaded its view hierarchy yet, your outlets are still nil.
You could force the VC to load its view hierarchy by saying _ = self.view.
Did you instantiate your view controller from a Storyboard or NIB, or did you instantiate it directly via an initializer?
If you instantiated your class directly with the initializer, the outlets won't be connected. Interface Builder creates customized instances of your classes and encodes those instances into NIBs and Storyboards for repeated decoding, it doesn't define the classes themselves. If this was your problem, you just need to change the code where you create your controller to instead use the methods on UIStoryboard, or UINib.
Have you tried running Product > Clean. Solved a very similar problem for me.
The storyboard wasn't recognizing any further UI things I added to it. At run time all the references were nil. So I cleared my derived data folder and then those connections worked again.
This happened for me because I was accidentally instantiating my view controller directly instead of instantiating it through the storyboard. If you instantiate directly via MyViewController() then the outlets won't be connected.
This was happening to me with my custom collection view cell. Turns out I had to replace my registerClassforReuseIdentifier method with registerNib. That fixed it for me.
In my case, it happened because I overriden the loadView method in my ViewController subclass, but forgot to add [super loadView]
-(void)loadView {
// blank
}
When you override the loadView method, the it is your responsibility to init your subviews. Since you override it, the views from interface builder do not get the chance to convert to cocoa objects and thus outlets remain nil.
If you implement loadView in your view controller subclass, then it becomes your responsibility load the UI elements from from storyboard/xib into code.
Or just call
[super loadView];
So that the superclass gets the chance to load storyboard/xib into code.
If you instantiate view controller through programmatically. Then
try creating it like below
let initialVC = self.storyboard?.instantiateViewController(withIdentifier: "InitialVC") as! InitialVC
instead of directly
let initialVC = InitialVC()
This worked for me.
You can call controller.view to force to load the view to initialize the IBOutlets, then you will be able to assign the values.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
if (segue.identifier == "identifier") {
let controller = segue.destinationViewController as! YourController
let _ = controller.view //force to load the view to initialize the IBOutlets
controller.your_IBOutlet_property = xxx
...
controller.delegate = self
}
}
I encounter this problem recently! Here is my thought.
The problem is not about you storyboard or any link issue. It is about how you initiate your ViewController. Especially when you are using Swift.(There is barely nothing in the editor when you create a class file)
By simply using the init() from super class can not initiate anything you worked with story board. So what you need to do is changing the initialisation of the ViewController. Replace
let XXViewController = XXViewController()
by
let XXViewController = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateViewControllerWithIdentifier("XXViewController") as! XXViewController
This tells the program to go to the storyboard find XXViewController and initiates all IBOutlet in your storyboard.
Hope this help~ GL
For me, this occurred when I accidentally declared my view controller's class as
class XYZViewController: UINavigationController {
}
(ie as a UINavigationController not a UIViewController).
Xcode doesn't pick up on this mistake, the class seems to build fine, and override functions such as viewDidLoad, viewWillAppear, etc. all work correctly. But none of the IBOutlets get connected.
Changing the declaration to
class XYZViewController: UIViewController {
}
fixed it completely.
2019, ONE POSSIBILITY FOR THIS HORRIBLE PROBLEM:
Say you have perhaps a container view that shows some sort of clock. So you have
class Clock: UIViewController
You actually use it in a number of places in the app.
On the main screen, on the details screen, on the edit screen.
You have a complicated snapchat-like modern app.
In fact, Clock may actually be loaded more than once at the same time somewhere on the same screen. (Maybe it's hidden in some cases.)
You start working on one instance of Clock on one of your many storyboards.
On that storyboard you add a label, NewLabel.
Naturally you add the outlet in code. Everything should work. All the other outlets work perfectly.
You have definitely linked the outlet.
But the app crashes with NewLabel as nil.
Xcode clearly tells you "you forgot to connect the outlet".
The reason is this .......... you have "NewLabel" on only one of the storyboard uses of Clock!
The crash is actually from >>> an other place <<<< you are using Clock!!!!
Xcode does not tell you the crash is from another place altogether, not from where you are working!
The crash is actually not from the place you are working - it's from another storyboard, where there is no "NewLabel" item on that storyboard!!!
Frustrating.
For Swift 3.
func configureView() {
let _ = self.view
}
In my case, the app started crashing all of a sudden.
Debugging it revealed that all outlets were still nil at the time of viewDidLoad().
My app still uses nibs (not storyboards) for most view controllers. Everything was in place, all outlets wired properly. I double-checked.
We typically instantiate our view controllers as
let newVC = MYCustomViewController()
...which for some reason seems to work as long as the .xib is named the same as the view controller class (not sure how that works, though. We are not calling init(nibName:bundle:) with nil arguments, or overriding init() to do so on self like it is typically suggested...).
So I tried to explicitly call
let newVC = MYCustomViewController(nibName: "MYCustomViewController", bundle: .main)
...only to be greeted with the runtime exception error:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not load NIB in bundle: 'NSBundle </Users/nicolasmiari/Library/Developer/CoreSimulator/Devices/3DA3CF21-108D-498F-9649-C4FC9E3C1A8D/data/Containers/Bundle/Application/C543DDC1-AE86-4D29-988C-9CCE89E23543/MyApp.app> (loaded)' with name 'MYCustomViewController''
And then, I saw it:
The "Target Membership" checkbox of the .xib file was unchecked.
Must have happened when resolving one of the frequent merge conflicts regarding the Xcode project file.
Apple definitely needs to come up with a project file format that is more SCM-friendly.
You need to load the view hierarchy first in order to instantiate the outlets in the storyboard. For this, you can manually call the loadView or loadViewIfNeeded methods.
100% Working solution for creating ViewControllers from XIB without StoryBoards
Create class CustomViewController : UIViewController
Create view CustomViewControllerView.xib
In CustomViewControllerView.xib in Interface Builder select Placeholders -> File's Owner
In "Attributes inspector" set Class to CustomViewController
In "Connections inspector" connect "view" to top-level view of xib (ensure top-level view's Class is not pointing to CustomViewController)
In "Connections inspector" connect other outlets (if needed/exist)
Create an instance of CustomViewController in parent view controller/App delegate
7.1.
// creating instance
let controller = CustomViewController()
7.2.
// connecting view/xib with controller instance
let bundle = Bundle(for: type(of: controller))
bundle.loadNibNamed("CustomViewControllerView", owner: controller, options: nil)
7.3.
// get/set outlets
controller.labelOutlet.text = "title"
controller.imageOutlet.image = UIImage(named: "image1")
Check your IBOutlet connection if it connected to the File owner or the view.
There could be mistakes.
Other case:
Your outlets won't get set until the view controller's view is actually instantiated, which in your case is probably happening shortly after initWithNibName:bundle:—at which point they'll still be nil. Any setup you do that involves those outlets should be happening in your view controller's -viewDidLoad method.
For me, I had same error on a localized storyboard, an element was added in some locale and not in the other, so I had null reference for that element when switched to the missing element locale, I had to remove (redundant) localization for that storyboard using https://stackoverflow.com/a/42256341/1356559.
For me, this was crashing because containerView was nil.
Here is my code with Crash.
#IBOutlet private var containerView: UIView! // Connected to Storyboard
override open func loadView() {
containerView.addSubview(anotherView)
}
The missing thing was calling the super.loadView(). So adding it solved problem for me.
Fixed Code:
#IBOutlet private var containerView: UIView!
override open func loadView() {
super.loadView()
containerView.addSubview(anotherView)
}
I had a similar issue when I had previously added register(_:forCellReuseIdentifier:) for the custom cell after I had already defined the identifier in the storyboard. Had this code in the viewDidLoad() function. Once I removed it, it worked fine.
Yet another case I just ran into. I changed the name of my class for the UIViewController, but I forgot to change the name of the .xib file where the interface was built.
Once I caught this and made the file names reflect the class name, it was all good!
I hope that helps someone.
Got one more ...
If you have a custom class for a UITableViewCell but forget to specify Custom in the Style of the cell.
Check to see if you have any missing or disconnected outlets.
You can validate if the is view is loaded.
if isViewLoaded && view.window != nil {
//self.annotationOptionsView.
}
select both .h and .m view controller files
remove the reference of those files
re-add the files to your project tree
open the storyboard, eventually re-build the project
Accidently I subclassed my view controller with AVPlayerViewController instead of UIViewController. By replaying it to UIViewController things back normal. This should help.
No build cleaning (normal&full), removing derived data folders and quitting Xcode worked for me.
I had the same problem after copying a class (linked to a xib) to reuse it with another viewcontroller class (linked to a storyboard).
I forgot to remove
override var nibName
and
override var nibBundle
methods.
After removing them, my outlets started to work.
I see you use ViewController!? in ViewController class you must use -viewDidLoad, not -awakeFromNib, -awakeFromNib use for UIView class
If you have two main.storyboards and you are making changes to the wrong one this can happen. This can happen anytime you connect an outlet from an uninstantiated storyboard.
I have this OSX storyboard-based application that starts with a NSSplitViewController like this:
This splitViewController has two viewControllers: master and detail.
Inside the window I have a NSToolbar. I dragged a NSProgressIndicator to that toolbar and Xcode embedded it inside a NSToolbarItem.
Now I need to create an outlet (not an action as explained on other stackoverflow questions) from the NSProgressIndicator to some class. First question is which one?
Xcode will not let I create an outlet. I have tried these options:
dragged from the ToolbarItem to masterController class file, detailController class file and to NSSplitViewController class.
dragged from the ToolbarItem to the delegate class.
dragged from the NSProgressIndicator to masterController class file, detailController class file and to NSSplitViewController class.
dragged from the NSProgressIndicator to the delegate class.
dragged from both the NSToolbarItem and from the NSProgressIndicator to the Window Controller First Responder.
In all cases dragging does not make a window appear to allow me to create the outlet.
For heavens sake, how do I create an outlet like that? To which class I drag it and how do I do that?
I'll assume your setup is more like this image:
Your Window scene is backed, by default, by an NSWindowController, to which you cannot add new outlets. You need to create a subclass of that, associate it with your Window and then you should be able to create outlets in that.
File > New File > Cocoa Class
Specify a name like "SpaceDogsWindowController", as a subclass of NSWindowController.
Then use select the window controller icon (blue circle) and select the Identity Inspector in Xcode. (CMD+ALT+3). Specify the name of your new class in the "Class" field.
Then try to hookup an outlet:
1) Show the Assistant Editor
2) Use the Jump Bar to ensure your custom class is visible (It's at the top of the assistant editor pane, it should say Automatic and you can tap that to then select your new class; If it says 'Manual', change it to Automatic).
3) If your are control-dragging and it's still not offering to make a connection, try dragging from the document outline (also shown in the screen shot).
You could then edit that progress indicator from other view controllers, which are descendants of that window's view hierarchy, using code like this:
if let windowController = self.view.window?.windowController() as? CustomWindowController {
windowController.progressIndicator.doubleValue = 0.4
}
or, in Objective-C, something like this:
CustomWindowController *myWindowControllerSubclass = self.view.window.windowController;
windowController.progressIndicator.doubleValue = 0.4;
Hope that helps.
I am new to using interface builder. Generally I create stuff programmatically but for this project in particular I have to use it, because I am working with a guy that just knows how to work with IB.
Said, that, I have to create a NSObject class and I want to create outlets from objects on interface builder to that class. Dragging the New Referencing Outlet (+) from interface builder to the class header is not doing the trick.
How do I do that?
In your class *.h add an outlet to the inferface, e.g.
IBOutlet NSButton *connectToThisButton; //choose the name you like
In IB CONTROL-drag from your button to the class, where your IBOutlet is defined. Leave the mousebutton and select connectToThisButton. Maybe you have to save it in XCode, before you can do this in IB.
Define a method for action after the end of the interface-section:
( IBAction) doSomeActionWithButton:(id)sender; //choose the name you like
In IB CONTROL-drag from your class to the button, where your IBOutlet is defined.