Hello,
i'm currently working through the book Intro to app development with Swift. At the moment i'm working on Lesson 17.3: Multiple Actions & Outlets.
I can built the app and run it in the simulator. But as soon as i want to turn on one switch i receive an error.
Unfortunately i can only find the solution for the final code of this project.
Maybe someone could help me understand & solve this error.
Error Code:
Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value 2019-04-13 20:16:58.584388+0200 Color_Mix[58605:3227076] Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value (lldb)
Main.Storyboard:
import UIKit class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. colorView.backgroundColor = .black } @IBOutlet weak var colorView: UIView! @IBOutlet weak var redSwitch: UISwitch! @IBOutlet weak var greenSwitch: UISwitch! @IBOutlet weak var blueSwitch: UISwitch! @IBAction func switchChanged(_ sender: UISwitch) { updateColor() } func updateColor() { var red: CGFloat = 0 var green: CGFloat = 0 var blue: CGFloat = 0 if redSwitch.isOn { red = 1 } if greenSwitch.isOn { green = 1 } if blueSwitch.isOn { blue = 1 } let color = UIColor(red: red, green: green, blue: blue, alpha: 1) colorView.backgroundColor = color } }
Hi, look in viewDidLoad method:
“From viewDidLoad(), remove the line that was setting the color and replace it with updateColor().” (p.128)