Giving UIView rounded corners

Try this

#import <QuartzCore/QuartzCore.h> // not necessary for 10 years now  :)

...

view.layer.cornerRadius = 5;
view.layer.masksToBounds = true;

Note: If you are trying to apply rounded corners to a UIViewController's view, it should not be applied in the view controller's constructor, but rather in -viewDidLoad, after view is actually instantiated.


Swift

Short answer:

myView.layer.cornerRadius = 8
myView.layer.masksToBounds = true  // optional

Supplemental Answer

If you have come to this answer, you have probably already seen enough to solve your problem. I'm adding this answer to give a bit more visual explanation for why things do what they do.

If you start with a regular UIView it has square corners.

let blueView = UIView()
blueView.frame = CGRect(x: 100, y: 100, width: 100, height: 50)
blueView.backgroundColor = UIColor.blueColor()
view.addSubview(blueView)

enter image description here

You can give it round corners by changing the cornerRadius property of the view's layer.

blueView.layer.cornerRadius = 8

enter image description here

Larger radius values give more rounded corners

blueView.layer.cornerRadius = 25

enter image description here

and smaller values give less rounded corners.

blueView.layer.cornerRadius = 3

enter image description here

This might be enough to solve your problem right there. However, sometimes a view can have a subview or a sublayer that goes outside of the view's bounds. For example, if I were to add a subview like this

let mySubView = UIView()
mySubView.frame = CGRect(x: 20, y: 20, width: 100, height: 100)
mySubView.backgroundColor = UIColor.redColor()
blueView.addSubview(mySubView)

or if I were to add a sublayer like this

let mySubLayer = CALayer()
mySubLayer.frame = CGRect(x: 20, y: 20, width: 100, height: 100)
mySubLayer.backgroundColor = UIColor.redColor().CGColor
blueView.layer.addSublayer(mySubLayer)

Then I would end up with

enter image description here

Now, if I don't want things hanging outside of the bounds, I can do this

blueView.clipsToBounds = true

or this

blueView.layer.masksToBounds = true

which gives this result:

enter image description here

Both clipsToBounds and masksToBounds are equivalent. It is just that the first is used with UIView and the second is used with CALayer.

See also

  • How to add borders and shadow
  • Bezier paths
  • Transformations

You can also use the User Defined Runtime Attributes feature of interface builder to set the key path layer.cornerRadius to a value. Make sure you include the QuartzCore library though.

This trick also works for setting layer.borderWidth however it will not work for layer.borderColor as this expects a CGColor not a UIColor.

You will not be able to see the effects in the storyboard because these parameters are evaluated at runtime.

Using Interface builder to set the corner radius