按下时，UILabel使应用程序崩溃

Question

Hi I am very new to programing for iOS apps and have come across this issue. I am sorry if it is a duplicate. I have searched thoroughly and have (tried) to read all relating threads to this issue but none have fixed it so far.

I am attempting to make a label that when pressed changes to something else. The label is created in another class and is put inside a view. Also I am trying to do this without putting a button behind it. Here is that code.

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var mountainImage: UIImageView!
@IBOutlet weak var mphView: Speed!


override func viewDidLoad() {
    super.viewDidLoad()
    setImage()
    mphView.backgroundColor = UIColor(white: 0.2, alpha: 0.5)
    mphView.layer.borderColor = UIColor(red: 222, green: 222, blue: 222, alpha: 1).CGColor
    mphView.layer.borderWidth = 1
    // Do any additional setup after loading the view, typically from a nib.
    let touchSpeedLabel = UITapGestureRecognizer(target: self, action: "speedLabelTouched")

    mphView.addGestureRecognizer(touchSpeedLabel)
    mphView.userInteractionEnabled = true
    }

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
    }
func setImage(){

    }
func speedLabelTouched(sender : UITapGestureRecognizer){
    print("Lol this worked")
    }
}

When I press the Label the app crashes with this error:

speedLabelTouched]: unrecognized selector sent to instance 0x157d838c0 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'unrecognized selector sent to instance 0x157d838c0'

Thanks in advance for helping!

Answer 1

You're telling it to use a method called "speedLabelTouched" (no parameters) but you've implemented a method called "speedLabelTouched:" (one parameter).

It, quite reasonably, can't find the no parameter version.