如何在UIImageView中获取圆形图像

Question

I tried to get a circle image using layer, here is my code

_compassArrow.layer.cornerRadius = _compassArrow.frame.size.width / 2;
_compassArrow.layer.masksToBounds = YES;
_compassArrow.layer.borderColor = [UIColor whiteColor].CGColor

the compassArrow is an imageview which display the compass image. And when I run my program, it looks terrible:

my actual picture

I don't know what happened to it. I've add some constraints to it, to make it has equal width with the device. Does this influence my image?

Answer 1

I think you set cornerRadius before your constraints are applied. Try to put this code in layoutSubviews or viewDidLayoutSubviews for example.

This way, the _compassArrow.frame.size.width value will be the one after constraints applied on it, and you'll get the correct cornerRadius.

Answer 2

Here is a piece of code that should allow you to do this.

        _compassArrow.layer.borderWidth = 1.0
        _compassArrow.layer.masksToBounds = false
        _compassArrow.layer.borderColor = UIColor.whiteColor().CGColor
        _compassArrow.layer.cornerRadius = profilePicture.frame.size.width/2
        _compassArrow.clipsToBounds = true