How to set corner radius of imageView?

Question

In Objective-C such line

self.mainImageView.layer.cornerRadius = CGRectGetWidth(self.mainImageView.frame)/4.0f;

does its job, I tried it in

Answer 1

Marked with @IBInspectable in swift (or IBInspectable in Objective-C), they are easily editable in Interface Builder’s attributes inspector panel.
You can directly set borderWidth,cornerRadius,borderColor in attributes inspector

extension UIView {

  @IBInspectable var cornerRadius: CGFloat {

   get{
        return layer.cornerRadius
    }
    set {
        layer.cornerRadius = newValue
        layer.masksToBounds = newValue > 0
    }
  }

  @IBInspectable var borderWidth: CGFloat {
    get {
        return layer.borderWidth
    }
    set {
        layer.borderWidth = newValue
    }
  }

  @IBInspectable var borderColor: UIColor? {
    get {
        return UIColor(cgColor: layer.borderColor!)
    }
    set {
        layer.borderColor = borderColor?.cgColor
    }
  }
}

Answer 2

import UIKit

class BorderImage: UIImageView {

    override func awakeFromNib() {
        self.layoutIfNeeded()
        layer.cornerRadius = self.frame.height / 10.0
        layer.masksToBounds = true
    }
}

Based on @DCDC's answer

Answer 3

There is one tiny difference in Swift 3.0 and Xcode8

Whenever you want to apply corner radius to UIView, make sure you call yourUIView.layoutIfNeeded() before calling cornerRadius.

Otherwise, it will return the default value for UIView's height and width (1000.0) which will probably make your View disappear.

Always make sure that all effects that changes the size of UIView (Interface builder constraints etc) are applied before setting any layer properties.

Example of UIView class implementation

class BadgeView: UIView {

  override func awakeFromNib() {

    self.layoutIfNeeded()
    layer.cornerRadius = self.frame.height / 2.0
    layer.masksToBounds = true

   }
 }

Answer 4

try this

self.mainImageView.layer.cornerRadius = CGRectGetWidth(self.mainImageView.frame)/4.0
self.mainImageView.clipsToBounds = true