Use Storyboard to mask UIView and give rounded corners?

Yes, I use that a lot but question like this was already answered many times.

But anyway in Interface Builder.You need to add User Defined Runtime Attributes like this:

layer.masksToBounds Boolean YESlayer.cornerRadius Number {View's Width/2}

and enable

Clips subviews

Results:

You can do it in a storyboard by using user-defined properties. Select the view that you want to round and open its Identity Inspector. In the User Defined Runtime Attributes section, add the following two entries:

• Key Path: layer.cornerRadius, Type: Number, Value: (whatever radius you want)
• Key Path: layer.masksToBounds, Type: Boolean, Value: checked

You may have to import QuartzKit in your view's corresponding class file (if any), but I swear that I've gotten it to work without doing that. Your results may vary.

EDIT: Example of a dynamic radius

extension UIView {    /// The ratio (from 0.0 to 1.0, inclusive) of the view's corner radius    /// to its width. For example, a 50% radius would be specified with    /// `cornerRadiusRatio = 0.5`.    @IBDesignable public var cornerRadiusRatio: CGFloat {        get {            return layer.cornerRadius / frame.width        }        set {            // Make sure that it's between 0.0 and 1.0. If not, restrict it            // to that range.            let normalizedRatio = max(0.0, min(1.0, newValue))            layer.cornerRadius = frame.width * normalizedRatio        }    }}

I verified that this works in a playground.

Select view

extension UIView {    @IBInspectable var cornerRadiusV: CGFloat {        get {            return layer.cornerRadius        }        set {            layer.cornerRadius = newValue            layer.masksToBounds = newValue > 0        }    }    @IBInspectable var borderWidthV: CGFloat {        get {            return layer.borderWidth        }        set {            layer.borderWidth = newValue        }    }    @IBInspectable var borderColorV: UIColor? {        get {            return UIColor(cgColor: layer.borderColor!)        }        set {            layer.borderColor = newValue?.cgColor        }    }}