Swift - UIButton created programatically doesn't trigger touch event

Question

I have created a button programatically and want to add a touch event handler. I have tried all the tricks I have found online but the desired function is just never triggered.

upgradeNowView = UIButton()
upgradeNowView.setTitle("Upgrade", forState: .Normal)
upgradeNowView.contentMode = UIViewContentMode.ScaleToFill
upgradeNowView.frame = CGRect(x: upgradeNowView.frame.minX, y: -50 , width: 320, height: 50)
upgradeNowView.userInteractionEnabled = true
upgradeNowView.sendActionsForControlEvents(.TouchUpInside)
upgradeNowView.addTarget(self, action: #selector(MainViewContainer.upgradeTapped(_:)), forControlEvents: .TouchUpInside)
side_menu_controller?.view.addSubview(upgradeNowView)

and defined this

func upgradeTapped(sender: UIButton)
{
    UpgradeViewController.openUpgrade()
}

But this just never gets called. Any help would be appreciated.

Answer 1

You need to define upgradeTapped function in class of side_menu_controller instance. I guess, it's SideMenuController class.

Answer 2

I found out this was caused by the fact that I was placing the button next to the view but outside its bounds (just on top):

upgradeNowView.frame = CGRect(x: upgradeNowView.frame.minX, y: -50 , width: 320, height: 50)

There are two ways around this:

• Move the button inside the bounds of the parent view, or
• Handle touches outside the view by overriding "hitTest" as discussed here