Width and Height Equal to its superView using autolayout programmatically?

Question

I\'ve been looking for a lot of snippets in the net and I still can\'t find the answer to my problem. My question is I have a scrollView(SV) and I want to add a button insid

Answer 1

I've picked the best elements from the other answers:

extension UIView {
  /// Adds constraints to this `UIView` instances `superview` object to make sure this always has the same size as the superview.
  /// Please note that this has no effect if its `superview` is `nil` – add this `UIView` instance as a subview before calling this.
  func bindFrameToSuperviewBounds() {
    guard let superview = self.superview else {
      print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
      return
    }

    self.translatesAutoresizingMaskIntoConstraints = false

    NSLayoutConstraint.activate([
      self.topAnchor.constraint(equalTo: superview.topAnchor),
      self.bottomAnchor.constraint(equalTo: superview.bottomAnchor),
      self.leadingAnchor.constraint(equalTo: superview.leadingAnchor),
      self.trailingAnchor.constraint(equalTo: superview.trailingAnchor)
    ])
  }
}

You can use it like this, for example in your custom UIView:

let myView = UIView()
myView.backgroundColor = UIColor.red

self.addSubview(myView)
myView.bindFrameToSuperviewBounds()