01_stackview.playground.swift

import UIKit
import PlaygroundSupport

let stackView = UIStackView()
stackView.distribution = .equalSpacing
stackView.alignment = .center
stackView.translatesAutoresizingMaskIntoConstraints = false

let bg = UIView(frame: CGRect(x: 0, y: 0, width: 500, height: 500))
bg.backgroundColor = .lightGray

let wrapper = UIView()
wrapper.layer.borderColor = UIColor.black.cgColor
wrapper.layer.borderWidth = 2
bg.addSubview(wrapper)
wrapper.translatesAutoresizingMaskIntoConstraints = false
wrapper.centerXAnchor.constraint(equalTo: bg.centerXAnchor).isActive = true
wrapper.centerYAnchor.constraint(equalTo: bg.centerYAnchor).isActive = true

wrapper.addSubview(stackView)
wrapper.leadingAnchor.constraint(equalTo: stackView.leadingAnchor).isActive = true
wrapper.trailingAnchor.constraint(equalTo: stackView.trailingAnchor).isActive = true
wrapper.topAnchor.constraint(equalTo: stackView.topAnchor).isActive = true
wrapper.bottomAnchor.constraint(equalTo: stackView.bottomAnchor).isActive = true

let viewgen = { (name: String, width: CGFloat, height: CGFloat, backgroundColor: UIColor) -> UIView in
    let view = UIView()
    view.backgroundColor = backgroundColor
    view.translatesAutoresizingMaskIntoConstraints = false
    view.widthAnchor.constraint(equalToConstant: width).isActive = true
    view.heightAnchor.constraint(equalToConstant: height).isActive = true
    let label = UILabel()
    label.text = name
    label.textColor = .white
    view.addSubview(label)
    label.translatesAutoresizingMaskIntoConstraints = false
    label.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
    label.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
    return view
}

stackView.addArrangedSubview(viewgen("v1", 50, 100, .red))
stackView.addArrangedSubview(viewgen("v2", 100, 50, .green))

PlaygroundPage.current.liveView = bg

02_rendered.png