Have multiple buttons have the same function? - ios

Question

I am creating an app where I need a button that generates more buttons. I have my code like this:
func showButtons(array:Array<UIButton>)
{
for(var i:Int = 0; i < array.count; i++)
{
array[i].setImage(UIImage(named: "StartButton.png"), forState: UIControlState.Normal)
array[i].frame = CGRectMake(CGFloat(arc4random_uniform(200)), CGFloat(arc4random_uniform(200)), 100, 100)
array[i].addTarget(self, action: "pressed", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(array[i])
}
}
The pressed button is this:
func pressed(sender:AnyObject?)
{
maybe()
}
But I know that is not the problem because another button, which was not create programmatically and has it's own action function, uses the same function and does not crash.
My crash report is here:
(104.0, 70.0)
2016-02-02 10:34:11.267 Test[5150:1087940] -[Test.ViewController pressed]: unrecognized selector sent to instance 0x7f8a8ac3be90
2016-02-02 10:34:11.283 Test[5150:1087940] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Test.ViewController pressed]: unrecognized selector sent to instance 0x7f8a8ac3be90'
* First throw call stack:
(
0 CoreFoundation 0x0000000101c81e65 exceptionPreprocess + 165
1 libobjc.A.dylib 0x00000001039c1deb objc_exception_throw + 48
2 CoreFoundation 0x0000000101c8a48d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x0000000101bd790a ___forwarding_ + 970
4 CoreFoundation 0x0000000101bd74b8 _CF_forwarding_prep_0 + 120
5 UIKit 0x00000001024a0194 -[UIApplication sendAction:to:from:forEvent:] + 92
6 UIKit 0x000000010260f6fc -[UIControl sendAction:to:forEvent:] + 67
7 UIKit 0x000000010260f9c8 -[UIControl _sendActionsForEvents:withEvent:] + 311
8 UIKit 0x000000010260eaf8 -[UIControl touchesEnded:withEvent:] + 601
9 UIKit 0x000000010250f49b -[UIWindow _sendTouchesForEvent:] + 835
10 UIKit 0x00000001025101d0 -[UIWindow sendEvent:] + 865
11 UIKit 0x00000001024beb66 -[UIApplication sendEvent:] + 263
12 UIKit 0x0000000102498d97 _UIApplicationHandleEventQueue + 6844
13 CoreFoundation 0x0000000101bada31 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17
14 CoreFoundation 0x0000000101ba395c __CFRunLoopDoSources0 + 556
15 CoreFoundation 0x0000000101ba2e13 __CFRunLoopRun + 867
16 CoreFoundation 0x0000000101ba2828 CFRunLoopRunSpecific + 488
17 GraphicsServices 0x0000000106297ad2 GSEventRunModal + 161
18 UIKit 0x000000010249e610 UIApplicationMain + 171
19 Test 0x0000000101aa134d main + 109
20 libdyld.dylib 0x00000001044ca92d start + 1
21 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
I believe my problem is I have all of e buttons attached to the action "pressed" so it sends a crash. Does anyone know a way to fix this/replace this. I have looked at the posts showing how to programmatically make a UIButton in Swift.

Answer 1

Your code has not problem at all with the number of UIButton associated to the same function, you're missing the colon at the end of the selector for the UIBUtton as your function receive a parameter in his signature, so you need to change the following line:
array[i].addTarget(self, action: "pressed:", forControlEvents:.TouchUpInside)
I hope this help you.

Answer 2

thanks to God (or Latter... ) now on Xcode 8 / Swift 3 syntax is cleaner, so no need to add (:_); compiler will find the method.
so the following code works fine:
override func viewDidLoad() {
super.viewDidLoad()
btn.addTarget(self, action: #selector(buttonTapped), for: UIControlEvents.touchUpInside)
}
final func buttonTapped(sender: UIButton){
}
if You try to mess compiler, i.e:
final func buttonTapped(sender: UIButton. fake: int){..
You will be called (as signature is correct..) but the parameter "fake" will get garbage from stack.
Of course:
final func buttonTapped(){..
works and is called. (no param is taken from stack).
By the way I prefer old syntax that required multiple ":" for every param, as per previous code:
"pressed:"