CODEWITHSUNDEEP
iosswiftswitch-statement
Alexey K
Alexey K

Reputation: 6723

Swift - determine which button was pressed with switch

I have 4 buttons that call one function. Depending on which button was pressed i need to hide button inside of function that called after pressing.I dont know which button was pressed so i tried to assign tags for each of 4 buttons to identify them by tag and use switch

I tried this

            switch sender.tag {
            case 1:
                self.button1.hidden = true
            case 2:
                self.button2.hidden = true
            case 3:
                self.button3.hidden = true
            case 4:
                self.button4.hidden = true

            }

but this doesnt work compiler says about use of unresolved identifier 'sender'

How to do this correctly ?

EDIT:

Whole function

  if self.allowMistakeVar {

        let mistakeAlert = UIAlertController(title: "Here is title!", message: "message of alert", preferredStyle: .Alert)
        let okay = UIAlertAction(title: "OK", style: .Cancel) { UIAlertAction in

            self.allowMistakeVar = false
            self.allowMistakeButton.enabled = false


            switch sender.tag {
            case answer1Text:
                self.answer1Text.hidden = true
            case answer2Text:
                self.answer2Text.hidden = true
            case answer3Text:
                self.answer3Text.hidden = true
            case answer4Text:
                self.answer4Text.hidden = true

            }

        }

        mistakeAlert.addAction(okay)
        self.presentViewController(mistakeAlert, animated: true, completion: nil )

    } else {

another case.. }

Upvotes: 8

Views: 20403

Answers (5)

GJ Nilsen
GJ Nilsen

Reputation: 715

I know this has been answered, but if you set this up in IB, then I would recommend you check if the button was pressed by using the @IBOutlet variables as cases.

class SomeView: UIView {
    @IBOutlet weak var buttonA: UIButton!
    @IBOutlet weak var buttonB: UIButton!
    @IBOutlet weak var buttonC: UIButton!

    @IBAction func didHitButton(_ sender: UIButton) {
        switch sender {
        case buttonA:
            doThis()
        }
        case buttonB:
            doThat()
        }
        case buttonC:
            doThisAgain()
        }
        default:
            doNothing()
        }
    }
    ...
}

Now you hook up the buttons in your NIB to each @IBOutlet, and all of the buttons to the one @IBAction didHitButton.

This is pretty straight forward, and you don't have to worry about tags or changing names.

Upvotes: 1

Matt G
Matt G

Reputation: 1

Rather then using a switch statement you can just use the sender directly.

Note that you need to specify that the sender is a UIButton (therefore this will only work if the function is only called from a button).

@IBAction func submitButton(sender: UIButton) {

    /* extra code here */

    sender.enabled = false

}

This reduces the code and also allows you to add extra buttons without code changes.

Upvotes: 0

Manikandan D
Manikandan D

Reputation: 1442

Try this,

1) Assign tag for each button

Button1.tag=1
Button2.tag=2
Button3.tag=3
Button4.tag=4

2) Then check your common button action

func buttonClicked(sender: UIButton)
{
   switch sender.tag {
   case 1: self.sender.hidden = true //button1
           break;
   case 2: self.sender.hidden = true //button2
           break;
   case 3: self.sender.hidden = true //button3
           break;
   case 4: self.sender.hidden = true //button4
           break;
   default: ()
           break;
   }

}

Upvotes: 11

JulianM
JulianM

Reputation: 2550

Why you always want to use tags to determine the UIButton ? If the called function has a sender parameter then you know the UIButton which called the function through this parameter.

func buttonClicked(sender: UIButton)
{
   switch sender {
   case button1: // Do something
   case button2: // Do some other stuff
   ...
   default: ()
   }

}

Upvotes: 10

Jecky
Jecky

Reputation: 478

Put your code in like below as i shown:

func btnSomeButtonClicked(sender: UIButton)
{
let tag = sender.tag;
       //put your same code here and either use tag variable as i shown or put as you did.
}

--> due to this you will get sender's property easily.

-->Also check that you didn't forgot to give tags to the UIButtons.

Upvotes: 4

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