Dynamically add buttons in swift - ios

Question

I am writing an iOS app. Server gives me buttons array to draw on view. So, the number of buttons can vary according to server response,
example:
let buttonArray=["Button 1","Button 2","Button 3"]
or
let buttonArray=["Button 1","Button 2","Button 3"," Button 4", "Button 5"]
I have to stack these buttons vertically.
I created a stackview, add constraints to it, and then add buttons to this stackview as arrangedsubviews.
Buttons should have gap of 5 points between them:
Using stackview:
func addButtonsUsingStackView()
{
//create stackview:
let stackView=UIStackView()
stackView.axis = .vertical
stackView.distribution = .fillEqually
stackView.alignment = .fill
stackView.spacing = 5
stackView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(stackView)
//stackview constraints:
let viewsDictionary = ["stackView":stackView]
let stackView_H = NSLayoutConstraint.constraints(
withVisualFormat: "H:|-20-[stackView]-20-|",
options: NSLayoutFormatOptions(rawValue: 0),
metrics: nil,
views: viewsDictionary)
let stackView_V = NSLayoutConstraint.constraints(
withVisualFormat: "V:|-30-[stackView]-30-|",
options: NSLayoutFormatOptions(rawValue:0),
metrics: nil,
views: viewsDictionary)
view.addConstraints(stackView_H)
view.addConstraints(stackView_V)
//adding buttons to stackview:
//let buttonArray=["Button 1","Button 2","Button 3"]
let buttonArray=["Button 1","Button 2","Button 3"," Button 4"]
for buttonName in buttonArray{
let button=UIButton()
button.setTitle(buttonName, for: .normal)
button.setTitleColor(UIColor.white, for: .normal)
button.backgroundColor=UIColor.blue
button.translatesAutoresizingMaskIntoConstraints=false
stackView.addArrangedSubview(button)
}
}
Without stackview:
var buttonArray=["Button 1","Button 2","Button 3"," Button 4"," Button 5"," Button 6"," Button 7"]
func addButtonsLoop()
{
for _view in view.subviews{
_view.removeFromSuperview()
}
var i=0
var buttonY = 20
let buttonGap=5
for btn in buttonArray {
let buttonHeight=Int(Int(view.frame.height) - 40 - (buttonArray.count * buttonGap))/buttonArray.count
print(buttonHeight)
let buttonWidth=Int(view.frame.width - 40)
let button = UIButton()
button.backgroundColor = UIColor.orange
button.setTitle(btn, for: .normal)
button.titleLabel?.textColor = UIColor.white
button.frame = CGRect(x: 20, y: buttonY, width:buttonWidth , height:buttonHeight)
button.contentMode = UIViewContentMode.scaleToFill
buttonY += buttonHeight + buttonGap
button.tag = i
button.addTarget(self, action: #selector(self.buttonTapped(_:)), for: UIControlEvents.touchUpInside)
view.addSubview(button)
i+=1
}
}
func buttonTapped( _ button : UIButton)
{
buttonArray.remove(at: button.tag)
addButtonsLoop()
}
My question is that instead of above code, how to apply NSLayoutConstraints or LayoutAnchors to solve this?

Answer 1

Instead of stack view you can use a tableview with the tableview cell containing a button and the number of rows can be the buttonarray count. In cellForRowAtIndexPath delegate method set the button title from button array.

Answer 2

you can use scroll view to add buttons.
var btnY = 5
let btnHeight = 40
func addButtonsUsingStackView()
{
for view in self.view.subviews{
view.removeFromSuperview()
}
for i in 0..< buttonArray.count {
let btnFloor = UIButton()
btnFloor.backgroundColor = Orange
btnFloor.titleLabel?.textColor = UIColor.white
btnFloor.frame = CGRect(x: 10, y: btnY, width: Int(scrView.frame.width - 20), height: btnHeight)
btnFloor.contentMode = UIViewContentMode.scaleToFill
btnY += btnHeight + 5
btnFloor.tag = buttonArray.index(of: i)
btnFloor.addTarget(self, action: #selector(self.btnTappedFloor(_:)), for: UIControlEvents.touchUpInside)
self.view.addSubview(btnFloor)
}
return cell
}
func btnTappedFloor( _ button : UIButton)
{
buttonArray.remove(at: button.tag)
addButtonsUsingStackView()
}