阴影没有出现 Swift 4.2

Question

I'm trying to add a drop shadow to a button with swift. I have created the elements on this view controller programmatically and I have a feeling this is why the shadow isn't appearing because the shadows appear in my other view controllers that I have in the app. I've also tried to deal with clipToBounds and maskToBounds but couldn't fix it. What am I missing?

Here is the code I'm using to try and get the shadow to appear.

let dateLabelButton: UIButton = {
    let button = UIButton()
    button.translatesAutoresizingMaskIntoConstraints = false

    button.layer.cornerRadius = 10
    button.backgroundColor = Colours().brightRedColour

    button.addTarget(self, action: #selector(segueToPopUp), for: .touchUpInside)

    let shadow = UIBezierPath(roundedRect: button.bounds, cornerRadius: 10).cgPath
    button.layer.shadowRadius = 5
    button.layer.shadowColor = UIColor.black.cgColor
    button.layer.shadowOpacity = 1
    button.layer.masksToBounds = false
    button.layer.shadowPath = shadow

    return button
}()

Here are the constraints that I've added to this button.

// Sets up layout for date label button
    dateLabelButton.bottomAnchor.constraint(equalTo: self.view.topAnchor, constant: self.view.frame.height * 2/3 - 50).isActive = true
    dateLabelButton.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
    dateLabelButton.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20).isActive = true
    dateLabelButton.topAnchor.constraint(equalTo: barChart.bottomAnchor, constant: 10).isActive = true
    dateLabelButton.heightAnchor.constraint(equalToConstant: 40).isActive = true

Any help would be great, I've been trying this for hours now and I just can't figure it out.

Answer 1

If you're using UIBezierPath for shadow, you need to do it inside the viewDidLayoutSubviews() , like so:

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    let shadow = UIBezierPath(roundedRect: dateLabelButton.bounds, cornerRadius: 10).cgPath
    dateLabelButton.layer.shadowRadius = 5
    dateLabelButton.layer.shadowColor = UIColor.black.cgColor
    dateLabelButton.layer.shadowOpacity = 1
    dateLabelButton.layer.masksToBounds = false
    dateLabelButton.layer.shadowPath = shadow
}

Otherwise, you can just comment out your shadowPath just like Enea's answer.

Answer 2

I think this will work.

let dateLabelButton: UIButton = {
    let button = UIButton()
    button.translatesAutoresizingMaskIntoConstraints = false

    button.layer.cornerRadius = 10
    button.backgroundColor = Colours().brightRedColour

    button.addTarget(self, action: #selector(segueToPopUp), for: .touchUpInside)

    //let shadow = UIBezierPath(roundedRect: button.bounds, cornerRadius: 10).cgPath
    button.layer.shadowRadius = 5
    button.layer.shadowColor = UIColor.black.cgColor
    button.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
    button.layer.shadowOpacity = 1.0
    button.layer.masksToBounds = false
   // button.layer.shadowPath = shadow

    return button
}()