I'm working with WatchKit, I have a simple interface with only a table but I get an error with just a few lines of code, maybe I forgot something really basic.
My interface:
the row inside the table has the identifier:
and the custom class:
The controller is implemented by this code:
import WatchKit
import Foundation
class ActiveListController: WKInterfaceController
{
#IBOutlet weak var tableView: WKInterfaceTable!
override func awakeWithContext(context: AnyObject?)
{
super.awakeWithContext(context)
loadData()
}
override func willActivate()
{
// This method is called when watch view controller is about to be visible to user
super.willActivate()
}
override func didDeactivate()
{
// This method is called when watch view controller is no longer visible
super.didDeactivate()
}
func loadData()
{
tableView.setNumberOfRows(10, withRowType: "ItemRow") // GET ERROR
for index in 0...9
{
let row = tableView.rowControllerAtIndex(index) as! ItemRow
row.nameLabel.setText("test")
}
}
}
and obviously I have my custom class for the single row
import Foundation
import WatchKit
class ItemRow : NSObject
{
#IBOutlet weak var checkImage: WKInterfaceImage!
#IBOutlet weak var nameLabel: WKInterfaceLabel!
}
So when I run the app I get error when I try to set the number of rows but really I can't understand what is nil:
fatal error: unexpectedly found nil while unwrapping an Optional value
Maybe it's a simple mistake, maybe not but please help me :\
The for loop in your code is going from 1...10 and it should be 0...9 because the rows are 0 based
finally I found my mistake.
I forgot to set my only one interface for Apple Watch as Initial Controller.
Yep, unbelievable and embarrassing but that's it. The error that provides Xcode it's not the best , it would be better something like "initial controller missing".
I hope my question & answer can help someone one day :)
Related
I understand it’s rather basic, but I’m only trying to get a grasp on basic functions.
I have produced some code by partially my own knowledge and partial bits from different guides.
I am not getting any errors, but the label is not displaying itself as “Text”. I believe it’s to do with the order/place my code is put.
Please help explain how I can fix this!
Please note as well:
I have just a single label called myLabel (named under the document section of my the identity inspector
It is has the text “Loaded” put into it already when I put it in.
I have no other code anywhere, only the default new project code.
I renamed the ViewController to ViewManager to avoid a class error.
First image: This is the image just so you know the location and other bits. I’ll attach the code too:
Second image: What I get, with no errors:
Third image: My main storyboard file:
And now it in code:
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var myLabel: UILabel!
#IBAction func labelSet() {
myLabel.text = "Text"
}
}
Make sure that the IBAction is connected to Touch Up Inside in Interface Builder.
Change the signature of the IBAction to
#IBAction func labelSet(_ sender: UIButton) {
Your function func labelSet() isn't called anywhere. Neither in the Storyboard nor elsewhere.
You can call it in viewDidLoad() like this:
override func viewDidLoad() {
super.viewDidLoad()
labelSet()
}
Alternatively call it after the label has loaded.
#IBOutlet weak var myLabel: UILabel! {
didSet {
labelSet()
}
}
maybe I am missing something really fundamental here, but after staring at the code for an hour or so, my brain is going trough cycles and I would appreciate a fresh glance at this problem.
I have the following UIView:
import UIKit
protocol DetailViewWillShowUpDelegate {
func sendDetailOpened(_ openedBool: Bool)
}
class locationXIBController: UIView {
#IBOutlet weak var loationLabel: UILabel!
#IBOutlet weak var vsedniOteviraciDobaLabel: UILabel!
#IBOutlet weak var prijmajiKartyLabel: UILabel!
#IBOutlet weak var detailViewButtonOutlet: UIButton!
#IBOutlet weak var backgroundViewButton: UIButton!
let openedBool = true
var detailViewWillShowUpDelegate: DetailViewWillShowUpDelegate?
override func awakeFromNib() {
super.awakeFromNib()
}
#IBAction func vecerkaDetailButtonPressed(_ sender: UIButton) {
detailViewWillShowUpDelegate?.sendDetailOpened(openedBool)
print("pressed")
}
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
if let result = detailViewButtonOutlet.hitTest(convert(point, to: detailViewButtonOutlet), with: event) {
return result
}
return backgroundViewButton.hitTest(convert(point, to: backgroundViewButton), with: event)
}
}
Now the problem is, that when I call/press the vecerkaDetailButtonPressed function I get "pressed" output in the console but the protocol for some reason doesn't go trough.
The other side looks like this (stripped for simplicity):
class MapViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
let locationXIB = locationXIBController()
let isVecerkaDetailOpened = false
override func viewDidLoad() {
locationXIB.detailViewWillShowUpDelegate = self
}
extension MapViewController: DetailViewWillShowUpDelegate {
func sendDetailOpened(_ openedBool: Bool) {
isVecerkaDetailOpened = openedBool
print("success")
}
}
I know the protocol value at the moment of execution is nil. As I said, any help is appreciated, thanks!
First, a couple of naming convention issues:
The name locationXIBController is a bad choice for a UIView object. It is a view object, not a controller object.
Second, class names in Swift should start with an upper-case letter. So LocationXIBView would be a much better name for that view class.
Next, your code
let locationXIB = locationXIBController()
...is wrong. That creates a brand-new instance of your locationXIBController class that you never install in your view hierarchy. You should make that line an IBOutlet:
#IBOutlet weak var locationXIB: locationXIBController!
And then you should control-drag from the locationXIBController in your StoryBoard onto the outlet in your view controller. That will cause Interface Builder to connect the outlet.
Now when you run your program the variable locationXIB will be connected to the locationXIBController view from your storyboard/XIB when it's loaded.
In addition to the answer of #Duncan C, you might check whether you need super.viewDidLoad() at the top of the viewDidLoad() method in the MapViewController class? Not doing that can lead to quirky things in your app.
I asked:
So does detailViewWillShowUpDelegate actually point at anything, or is it nil?
And you replied:
I just tried debugging and it is actually nil
So that's the problem... you need to set detailViewWillShowUpDelegate to point to a valid delegate object. This is often done in the .xib file or storyboard, and sometimes people forget to make that connection, so check there if it makes sense. Else you'll just need to get a reference to the delegate at some point before the code in question can run and set it up.
Answer to the credit of #Paulw11
I finally managed to get it working by communicating like so:
step 1) 1:1 communication via protocol between MKAnnotation and MKAnnotationView
step 2) 1:1 communication via protocol between MKAnnotationView and MapViewController passing the same data
Finally works like a charm, thanks!
I get a problem in using container view and segmented control to achieve switch views.I have put two container views in one view controller, and each of container view embed a new view(three view controller in the same UIViewController).
Here is my code
import UIKit
import Charts
class ReportViewController: UIViewController {
#IBOutlet weak var containerTwoWeeks: UIView!
#IBOutlet weak var containerToday: UIView!
#IBOutlet weak var segUi: UISegmentedControl!
#IBOutlet weak var resultLabel: UILabel!
#IBOutlet weak var paymentPie: PieChartView!
#IBOutlet weak var incomePie: PieChartView!
override func viewDidLoad() {
super.viewDidLoad()
// pieChartUpdate()
// selectResultData()
}
#IBAction func segChange(_ sender: UISegmentedControl) {
switch segUi.selectedSegmentIndex {
case 0:
self.containerTwoWeeks.isHidden = false
self.containerToday.isHidden = true
break
case 1:
self.containerTwoWeeks.isHidden = true
self.containerToday.isHidden = false
break
default:
break
}
}
func selectResultData() {
resultLabel.attributedText = reportService.selectResultData()
}
func pieChartUpdate () {
(too much code here, ignore it)
}
}
Everything works well until I called the method pieChartUpdate() or selectResultData() in vieDidLoad(),the error message as below
"Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value"
I can switch the views without calling the pieChartUpdate() or selectResultData() method, so I really want to know the reason and solution.Hope someone could figure out this problem,thanks.
You got very common mistake and error. But don't worry.
Check your full error message. There must be a clue what variable you are trying to access and getting nil (it might be resultLabel).
Then make sure the connection between storyboard and view controller for this variable is correct. You can try to remove and create it again if you don't get what is wrong.
If you need more help, please show us full error message.
[Problem soluted!Just want to know why there is such a difference in ios8 and ios9] I was making a register view controller these days and face with some problem about weak reference.
and below is some part of the code(swift)
problem come when I use an iphone6 ios8.1
it crashed. And then I noticed that the weak reference is not proper here. But the code runs well in my ios9 iphone6s. I ran this code on an iphone6 ios8 simulator, app crashed. So I think there is some thing different in processing weak reference in ios8 and ios9, But who can explain why..?
class VC: UIViewController {
weak var verifyTextField: UITextField?
override func viewdidload() {
//....
verifyTextField = newTextField();
view.addSubview(verifyTextField!);
}
func newTextField() -> UITextField {
let ntf = UITextField();
//do some settings to ntf;
return ntf;
}
}
You set your new UITextField instance to the weak var verifyTextField but before you add it as a subview (which increments the retain count) it is deallocated (the count is 0 since the var is weak) so verifyTextField! crashes, the crash you're getting is most likely the famous
Unexpectedly found nil while unwrapping an Optional
It's easy to fix it
Don't use a weak var
Don't force unwrap (use if let instead)
The code should be as follows:
class VC: UIViewController {
var verifyTextField: UITextField? //should not be weak
override func viewdidload() {
//....
verifyTextField = newTextField()
if let verifyTextField = verifyTextField {
view.addSubview(verifyTextField!)
}
}
func newTextField() -> UITextField {
let ntf = UITextField()
//do some settings to ntf
return ntf
}
}
Looks like your object is deallocated instantly after initialization because you don't store any strong reference for it.
Try this code:
override func viewdidload() {
//....
let verifyTextField = newTextField();
view.addSubview(verifyTextField);
self.verifyTextField = verifyTextField;
}
Also no need to use weak reference here, because verifyTextField doesn't have reference to your VC, so you won't get a retain cycle.
I have this file named FoodHandler.swift, and I'm trying to have it appear inside of a label, and I'm getting the error "fatal error: unexpectedly found nil while unwrapping an Optional value" This will open in a println() on the new page,
Here's my code inside of FoodHandler.swift
import Foundation
import UIKit
var FoodType = ""
class SwitchSegue
{
}
Here's my code on the new View Controller
#IBOutlet var lblChose: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidAppear(animated: Bool) {
println(FoodType) // Works
lblChose.text = FoodType // Throws a nil exception
}
Does anyone know why this is?
The error isn't about FoodType. You can tell because FoodType is not an optional value at all... but lblChose is. It's an "implicitly unwrapped optional", which you can read about here; it's indicated by the ! after its declaration.
Check to be sure that the lblChose outlet is connected properly in the interface.
Without seeing anymore of your code, I'd assume the issue is with the label not existing. You have declared it as an optional, but it may not be connected with a label on the storyboard. Usually when you connect them from storyboard they will be weak:
#IBOutlet weak var lblChose: UILabel!
You should try using (as far as I understood the println is displaying the correct value right?):
lblChose.text = FoodType!