UIButton as subview programmatically constraint - ios

Question

I have one UIScrollView (IBOutlet) with success constraint inside a storyboard. then I programmatically create UIButton and put them as a subview to UIScrollView. how do I programmatically set these UIButton constraints so their height and size would tally with their super view?
class ViewController: UIViewController {
#IBOutlet weak var aScrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var xCoord: CGFloat = 5
let yCoord: CGFloat = 5
let buttonWidth:CGFloat = 100
let buttonHeight: CGFloat = 100
let gapBetweenButtons: CGFloat = 10
var itemCount = 0
// MARK: - filter buttons
for i in 0..<6 {
itemCount = i
let aButton = UIButton(type: .custom)
aButton.frame = CGRect(x: xCoord, y: yCoord, width: buttonWidth, height: buttonHeight)
aButton.backgroundColor = UIColor.blue
aButton.layer.cornerRadius = aButton.frame.size.width / 2
aButton.clipsToBounds = true
xCoord += buttonWidth + gapBetweenButtons
aScrollView.addSubview(aButton)
}
}

Answer 1

Try this --
This is just an idea about how to add constraint programmatically.
For more understanding you can go through below link - https://developer.apple.com/reference/appkit/nslayoutanchor
let myButton = UIButton()
self.aScrollView.addSubview(myButton)
self.view.translatesAutoresizingMaskIntoConstraints = false
let margins = self.view.layoutMarginsGuide
myButton.leadingAnchor.constraint(equalTo: forView. aScrollView.leadingAnchor, constant: 5).active = true
myButton.topAnchor.constraint(equalTo: forView. aScrollView.topAnchor, constant: 5).active = true
myButton.heightAnchor.constraintEqualToConstant(100.0).active = true
myButton.widthAnchor.constraintEqualToConstant(100.0).active = true

Answer 2

Change your code to:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var xCoord: CGFloat = 5
let yCoord: CGFloat = 5
let gapBetweenButtons: CGFloat = 10
let buttonCount = 6
let buttonWidth = (aScrollView.frame.width - CGFloat(buttonCount - 1) * gapBetweenButtons - xCoord - xCoord) / CGFloat(buttonCount) // - (2 * xCoord) = - (margin left + margin right).
let buttonHeight = buttonWidth
var itemCount = 0
// MARK: - filter buttons
for i in 0..<buttonCount {
itemCount = i
let aButton = UIButton(type: .custom)
aButton.frame = CGRect(x: xCoord, y: yCoord, width: buttonWidth, height: buttonHeight)
aButton.backgroundColor = UIColor.blue
aButton.layer.cornerRadius = aButton.frame.size.width / 2
aButton.clipsToBounds = true
xCoord += buttonWidth + gapBetweenButtons
aScrollView.addSubview(aButton)
}
}

Answer 3

This is how to do it. I made a video tutorial for you add unbutton programmatically to scrollview in iOS, swift. please refer the link.
add a scrollview (add constraints -> top, bottom, left, right).
then add a view to your scroll view (add constraints -> top, bottom, left, right, width, height and set width and height as you need. explain in the video)
add those two views as subviews.
then add the button and its constraints programmatically.
follow the video tutorial. add UIButton(outlet) to scrollview programmatically