Last Button in UIScrollView add target doesn't effect - ios

Question

I have a list of category add I created buttons for each category in a scroll view
and a last button is ALL button for all products. But some how it didn't have any action I added.
this is my code
First I make a function to create buttons to add to view
func catButtonView(buttonSize:CGSize) -> UIView {
let buttonView = UIView()
buttonView.backgroundColor = UIColor(colorLiteralRed: 1, green: 1, blue: 1, alpha: 0)
buttonView.frame.origin = CGPoint(x: 0,y: 0)
let padding = CGSize(width:0, height:0)
buttonView.frame.size.width = (buttonSize.width + padding.width) * CGFloat(categories.count)
buttonView.frame.size.height = (buttonSize.height + 2.0 * padding.height )
//add buttons to the view
var buttonPosition = CGPoint(x:padding.width * 0.5, y:padding.height)
let buttonIncrement = buttonSize.width + padding.width
let hueIncrement = 1.0 / CGFloat(categories.count)
var newHue = hueIncrement
for i in 0...(categories.count) {
let button = UIButton.init(type: .custom) as UIButton
button.frame.size = buttonSize
button.frame.origin = buttonPosition
button.setBackgroundImage(R.image.button(), for: .normal)
button.setBackgroundImage(R.image.button_selected(), for: .selected)
if(i==categories.count) {
button.setTitle("ALL", for: .normal)
} else {
button.setTitle(categories[i].name, for: .normal)
}
button.setTitleColor(UIColor.white, for: .normal)
buttonPosition.x = buttonPosition.x + buttonIncrement
newHue = newHue + hueIncrement
button.tag = i+1
button.addTarget(self, action: #selector(catButtonPressed(sender:)), for: .touchUpInside)
buttonView.addSubview(button)
}
return buttonView
}
this is action func
func catButtonPressed(sender:UIButton){
print(sender.tag)
if(self.selectedCat != sender.tag-1) {
let lastBtn = catScrollView.viewWithTag(selectedCat+1) as? UIButton
lastBtn?.setBackgroundImage(R.image.button(), for: .normal)
self.selectedCat = sender.tag-1
self.itemsCollection.reloadData()
sender.setBackgroundImage(R.image.button_selected(), for: .normal)
}
}
then add to scroll view
let catScrollingView = catButtonView(buttonSize: CGSize(width: 200.0, height:50.0))
catScrollView.contentSize = catScrollingView.frame.size
catScrollView.subviews.forEach({ $0.removeFromSuperview() })
catScrollView.addSubview(catScrollingView)
catScrollView.showsHorizontalScrollIndicator = true
catScrollView.indicatorStyle = .default
self.itemsCollection.reloadData()
Anyone know what I missed?

Answer 1

It is because the if statement in your catButtonPressed function is false with the last button's tag, which makes the code inside never be executed.
Let's say you have 5 categories so your categories.count = 5. So your self.selectedCat ranges from 0 to 4. In your for i in 0...(categories.count) the last button's tag is button.tag = 5
Now in your catButtonPressed function. If the last button is the last category, then your self.selectedCat will be 4 and sender.tag will be 5
func catButtonPressed(sender:UIButton){
print(sender.tag)
if(4 != 5-1) {
// Any code in here will never be executed because 4 != 4 is false
}
}