I know that there are a lot of questions about this error, but I haven't found solution for my problem, even if I read most of them. In view controller I'm trying to make my text view displaying top of text, instead of bottom of it. When there is only one textView, then everything works perfectly, but when I try do it with two of the, , then I get EXC_BAD_INSTRUCTION error.
import UIKit
import Social
class ViewController: UIViewController {
#IBOutlet weak var textViewA: UITextView!
#IBOutlet weak var textViewB: UITextView!
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
textViewA.setContentOffset(CGPointZero, animated: false)
textViewB.setContentOffset(CGPointZero, animated: false)
}
If your error is like this
Then it is because you have not hooked up your outlets, to do this go into the storyboard / nib and hook it up like so:
Make sure they are valid by seeing the circles become solid:
This code works for me. I tested it on my own. This is mostly an outlet error, if they aren't connected correctly. It could also be that you have removed an outlet from your code and still have it connected inside your storyboard.
Related
import UIKit
class ViewController: UIViewController {
#IBOutlet var continueLabel: UILabel!
#IBOutlet var yesButton: UIButton!
#IBOutlet var noButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
continueLabel.isHidden=true
yesButton.isHidden=true
noButton.isHidden=true // Do any additional setup after loading the view.
}
#IBAction func continueButton(_sender: UIButton) {
continueLabel.isHidden=false
yesButton.isHidden=false
noButton.isHidden=false
}
}
I'm a bit new to IOS development and was practicing how to hide/unhide a button. On the view controller, I can get the button hidden but when I press the button to unhide - The following error is being thrown reason: '-[WelcomeApp.ViewController ContinueButton:]: unrecognized selector sent to instance 0x12b2061d0.
It was basically a button which displayed two options - Yes or No. The Yes button is linked to the next view controller modally.
Function names, as variables, are case sensitive. You seem to have linked to ContinueButton() function, and then to have renamed it to continueButton(). Remove the link and recreate it, and then it should work.
Check the connection inspector as shown in the pic:
You can see a yellow warning, you have to remove this connection first and then again make the connection.
I am trying to change a picture and a label programmatically.
Here's the current code setup:
#IBOutlet weak var image: UIImageView!
#IBOutlet weak var label: UILabel!
override func viewDidLoad(){
super.viewDidLoad()
setlabel()
setImage()
}
func setImage(){
self.image.image = UIImage(named: name)
}
func setlabel(){
self.label.text = string
}
But unfortunately, I'm receiving nil for both UI elements, the label and the image. I've doublechecked the connection between my storyboard and the variables- they are set correctly, imho. They are available, since I am calling them outside the viewDidLoad function.
Anyone any suggestion?
Regards
I found the solution. I had 2 views- let's call them A and B.
A contained a button- and the button had 2 functions: Change the view and set the labels/images. Those functions were defined in the Controller of view A.
Since I wanted to change the labels and images of view B, I got the exception.
I had to include another Controller and transfer the functions for setting the images and labels to Controller B. Voila, I could change the images and labels.
Summarized: I had the right connections and the right functions, but in the wrong place.
Thank you all!
i have dragged a container view from storyboard and set it black in background colour. but it didn't change the background colour.
class ViewController: UIViewController {
#IBOutlet weak var container: UIView!
override func viewDidLoad() {
super.viewDidLoad()
container.layer.backgroundColor = UIColor.blackColor().CGColor
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
How did you set the background color?
A container view is actually just a normal view, that is linked to a viewController. This means you can set the background the same way as you would for any other NSView or UIView. This is all the code I needed to add to my NSViewController class (not the ViewController inside the container, just the ViewController for the window).
#IBOutlet weak var containerView: NSView!
override func viewDidLoad() {
//other code in your viewDidLoad
containerView.wantsLayer = true
}
override func awakeFromNib() {
super.awakeFromNib()
containerView.layer?.backgroundColor = NSColor.black.cgColor
}
make sure to connect the IBOutlet if you have not already.
If you set the layers background color in viewDidLoad, the layer may not exist yet, (I don't know why). Accessing the layer in awakeFromNib has always worked for me, while accessing it in the viewDidLoad can be unreliable.
If you are working on IOS, most of this is not applicable, and this should be all you need
#IBOutlet weak var containerView: UIView!
override func viewDidLoad() {
containerView.layer?.backgroundColor = UIColor.black.cgColor
}
I work less on IOS, so I have not ran into any issues with that, but that could be from lack of attempts. On OSX setting the background color in viewDidLoad will work about 50% of the time so there might still be an issue that I have not ran into.
If neither works, try unwrapping the layer rather than leaving it an optional (replacing the ? with a !) this will at least crash your program and probably tell you that layer is nil, if this is the case you should be figuring out why the layer is nil.
Also if the ViewController connected to the container view is a custom class, you don't have to bother with the IBOutlets, just call the view "view" in that custom class.
Sorry this got a bit long, but hope this helped
I'm trying to learn Swift, but I seem to have gotten stuck at this (admittedly, probably very simple) problem - the error as follows:
Could not connect action, target class NSViewController does not respond to -(encbutton/decbutton)
Here is my code. I'm designing my interface in the Storyboard and connecting it to the code through #IB(Outlet/Action).
// ViewController.swift
import Cocoa
import Foundation
class TabViewController: NSTabViewController {
// This has been changed from NSViewController to NSTabViewController as I have replaced the initial single-view with a two-tab-view.
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override var representedObject: AnyObject? {
didSet {
// Update the view, if already loaded.
}
}
}
public class EncViewController: NSViewController {
// This is for the first tab, encrypt
#IBOutlet var encdirfield: NSTextField!
#IBOutlet var encpassfield: NSSecureTextField!
#IBOutlet var enclogfield: NSTextField!
#IBOutlet var encbutton: NSButton!
#IBAction func startenc(sender: NSButton) { // here's the problem. the function isn't triggered when the button is pressed
// get values
encdir = encdirfield.stringValue
encpass = encpassfield.stringValue
tarcrypt.enc();
// this is an function that leads to an NSTask that runs a binary I wrote (not related).
// definitely not the cause of the problem because running it independently works fine
}
}
public class DecViewController: NSViewController {
// and this is for the second tab, decrypt
#IBOutlet var decdirfield: NSTextField!
#IBOutlet var decpassfield: NSSecureTextField!
#IBOutlet var declogfield: NSTextField!
#IBOutlet var decbutton: NSButton!
#IBAction func startdec(sender: NSButton) { // here's the same problem, again. the function isn't triggered when the button is pressed
// get values
encdir = encdirfield.stringValue
encpass = encpassfield.stringValue
tarcrypt.dec();
// this is an function that leads to an NSTask that runs a binary I wrote (not related).
// definitely not the cause of the problem because running it independently works fine
}
}
For some reason, upon drawing the scene along with the NSButton, the error message as seen above is generated. What is causing the error, and how do I fix it?
I've figured it out! For anyone else who runs into this problem, here's how to fix it:
It turns out there is a little dropdown under "Custom Class" titled "Module", which is, by default, set to none. Set it to tarcrypt (or whichever available option suits you) and that should fix the errors.
Thanks for all the help!
It sounds as if you connected your UI element to the File's Owner object, which is an instance of NSApplication.
If you haven't done so already, you want to drag a NSObject out of the Object Library palette in Xcode 4 to the margin to the left of your layout. Once you've done that, and have selected it, choose the identity inspector and, in the Class field, enter "WindowController"
Swift 5 and Xcode 13.3
Recently I had the same bug. I solved it by reassigning the viewcontroller class name to the class in my nameclass.swift file and activating the MODULE entry with my project name (following the dropdown menu).
I am using swift and want a UITextView to be at the top when the view launches. At the moment when I launch the app the UITextView is scrolled to the end. I have tried looking online and think scrollRangeToVisible might work but do not know how to use it in swift.
import UIKit
class ThirdViewController: UIViewController {
#IBOutlet weak var FunFact: UITextView!
override func viewDidLoad() {
super.viewDidLoad()
FunFact.scrollRangeToVisible(0, 0)
// Do any additional setup after loading the view.
}
}
Add this to your ViewController:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
textView.layoutIfNeeded()
textView.contentOffset = CGPoint.zero
}
This scrolls the UITextView to the top. Since it only knows its size, when it is layouted, "layoutIfNeeded" is needed after you changed the text (i changed it in viewDidLoad).
Try this:
var zeroOffset = CGPoint.zeroPoint
FunFact.contentOffset(zeroOffset)
This should bring the offset to 0 (the offset is an indication of how far the current position is from the initial one)