Swift 3: Unrecognized selector sent to instance Xcode 8

ios swift swift3 uigesturerecognizer

31,187

Solution 1

If you are using swift 3 your selector should be like this

#selector(self.handleTap(recognizer:))

Solution 2

You should write this statement in different way. use following line

let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(ViewController.handleTap(_:)))

instead of

let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: Selector(("handleTap:")))

New Way

let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(YourViewController.handleTap(_:)))

Solution 3

class ViewController: UIViewController {

    let customView = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()

        let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handleTap(_:)))
        customView.addGestureRecognizer(panGestureRecognizer)
    }

    func handleTap(panGesture: UIPanGestureRecognizer) {

    }
}

Don't forget to add your custom UIView to the VC.

31,187

Author by

Raul

Updated on September 06, 2020

Comments

Raul over 3 years
I have programmatically created an UIView and added UIPanGestureRecognizer to it:
```
class ViewController: UIViewController{
    var preludeView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        initViews()
        createConstrants()

        let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: Selector(("handleTap:")))
        preludeView.addGestureRecognizer(panGestureRecognizer)
    }

    func handleTap(recognizer: UIPanGestureRecognizer) {
        print("WORKING!!!!")
    }

    func initViews() {
        ...
    }

    func createConstrants() {
        ...
    }
}
```
But when I am touching the view Xcode is throwing an error:

2016-07-13 09:24:29.918 Draft_Hypa_02[661:83024] -[Draft_Hypa_02.ViewController handleTap:]: unrecognized selector sent to instance 0x17d94a10 2016-07-13 09:24:29.921 Draft_Hypa_02[661:83024] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Draft_Hypa_02.ViewController handleTap:]: unrecognized selector sent to instance 0x17d94a10' * First throw call stack: (0x249cf91b 0x2416ae17 0x249d52b5 0x249d2ee1 0x248fe238 0x294ae9eb 0x290e984f 0x28f7aff1 0x294afd4f 0x28f3ba57 0x28f38017 0x28f78ec9 0x28f7867b 0x28f49125 0x28f476d3 0x24991dff 0x249919ed 0x2498fd5b 0x248df229 0x248df015 0x25ecfac9 0x28fb1189 0x93144 0x24587873) libc++abi.dylib: terminating with uncaught exception of type NSException

However, if I remove argument in the handleTap function and remove the colon in the Selector(("handleTap:")), everything works fine!

Already spent a day to try to fix this issue and would be very appreciate for your help!
Raul almost 8 years

Xcode is throwing "Value of type 'ViewController' has no member 'handleTap'"
Raul almost 8 years

Xcode 8 is throwing "Value of type 'ViewController' has no member 'handleTap'"
Raul almost 8 years

I am adding UIView in initViews() and put this function in the viewDidLoad()
Leo Dabus almost 8 years

@Forze you need also to add an underscore before the method first parameter. func handleTap(_ recognizer: UIPanGestureRecognizer) {
Raul almost 8 years

@Nirav thanks, It works! Do you know in Swift 3 we must set external name for action function?
Nirav D almost 8 years

Yes in swift 3 to call the first parameter you must write parameter name, you can check this for more info
Mahendra Y almost 8 years

use self instead of ViewController or name of your viewController
Mahendra Y over 7 years

@Forze: handleTap is name of method, You are calling func handleTap(sender: UIPanGestureRecognizer){}
Markinson over 7 years

@Mahendre I used self and its still giving the same error
Mahendra Y over 7 years

@Markinson Can you post your function and its calling syntax
Markinson over 7 years

@Mahendre Y I figured it out. Your code was right. I just forgot to write the name of my .swift file before calling the func
Luda over 7 years

@LeoDabus, you comment helped me a lot!