swift: Adding an action to an array of buttons

Question

I'm designing a simple Sudoku app and need to trigger an action when any one of the 81 buttons are clicked. I created an array of UIButtons in my ViewController:

class SudokuBoardController : UIViewController {
@IBOutlet var collectionOfButtons: Array<UIButton>?

  override func viewDidLoad() {

    collectionOfButtons.addTarget(self, action: "buttonClicked:", forControlEvents: UIControlEvents.TouchUpInside)

    ...
  } 
}

I'm able to add the buttons to the Array from the storyboard ok, its just when I try to addTarget I get this message:

Value of type 'Array<UIButton>?' has no member addTarget

Is there a solution to this problem that does not involve me creating 81 different outputs for each button?

Thanks for your help!

Cheers

score 5 · Answer 1 · answered Feb 05 '16 at 16:01

You have an Array, so you want to iterate over the UIButtons in the array. And because you're in Swift, you'll want to do so in a Swifty way, not using a simple for loop.

collectionOfButtons?.enumerate().forEach({ index, button in
    button.tag = index
    button.addTarget(self, action: "buttonClicked:", forControlEvents: .TouchUpInside)
})

This also nicely handles the fact that collectionOfButtons is an optional by doing nothing if it is nil, as opposed to crashing.

Thank you! This answer worked too. Much obliged. :) – colinmcp Feb 05 '16 at 16:06 — colinmcp, Feb 05 '16 at 16:06

score 2 · Accepted Answer · answered Feb 05 '16 at 15:51

2

You need to iterate through array of buttons and add target to each of the button. Try out following code

var index = 0
for button in collectionOfButtons! {
    button.tag = index // setting tag, to identify button tapped in action method
    button.addTarget(self, action: "buttonClicked:", forControlEvents: UIControlEvents.TouchUpInside)
    index++
}

answered Feb 05 '16 at 15:51

Vishnu gondlekar

3,896
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Awesome, this worked, thanks Vishnu from a very grateful Swift newbie! :) – colinmcp Feb 05 '16 at 16:06

swift: Adding an action to an array of buttons

2 Answers2