I have created a UIView and tried adding it with view.addSubview but its not showing up for some reason.

This is my UIViewController:

private let titleLabel: UILabel = { // Create a UILabel programatically
    //...
}()

private let emailContainerView: UIView = {
    let view = UIView()
    
    view.backgroundColor = .blue
    
    return view
}()

override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = UIColor.init(red: 25/255, green: 25/255, blue: 25/255, alpha: 1)
    
    addSubviews()
    layout()
    
}

//A function for adding new subviews
private func addSubviews() {
    view.addSubview(emailContainerView)
    view.addSubview(titleLabel)
}

//A function for autolayout
private func layout() {
    titleLabel.anchor(top: view.safeAreaLayoutGuide.topAnchor)
    titleLabel.centerX(inView: view)
    
    emailContainerView.anchor(top: titleLabel.bottomAnchor, left: view.leftAnchor, right: view.rightAnchor, paddingTop: 40, paddingLeft: 16, paddingRight: 16, height: 50)
}

And i also created a function(anchor) which handles my constraints.

func anchor(top: NSLayoutYAxisAnchor? = nil,
            left: NSLayoutXAxisAnchor? = nil,
            bottom: NSLayoutYAxisAnchor? = nil,
            right: NSLayoutXAxisAnchor? = nil,
            paddingTop: CGFloat = 0,
            //padding left,right,bottom is the same
            width: CGFloat? = nil,
            height: CGFloat? = nil) {
    
    translatesAutoresizingMaskIntoConstraints = false
    
    if let top = top {
        topAnchor.constraint(equalTo: top, constant: paddingTop).isActive = true
    }
    
    if let left = left {
        leftAnchor.constraint(equalTo: left, constant: paddingLeft).isActive = true
    }
    
    if let bottom = bottom {
        bottomAnchor.constraint(equalTo: bottom, constant: -paddingBottom).isActive = true
    }
    
    if let right = right {
        rightAnchor.constraint(equalTo: right, constant: -paddingRight).isActive = true
    }
    
    if let height = height {
        widthAnchor.constraint(equalToConstant: height).isActive = true
    }
    //Width...
    
}

And this is what i see after running my project on Iphone 13 mini simulator

CodePudding user response：

At the last in function anchor you are settinh width but you also giving left and right anchor this will cause visual issue .

I think you wanted set it

   if let height = height {
    heightAnchor.constraint(equalToConstant: height).isActive = true // change width to height
    }

if let bottom = bottom { .. } is not gonna work because you are not passing any value from anchor function . so your view has top,left,right and now (with above code) height . Everything must work