UIView* viewWithRoundedCornersSize(float cornerRadius,UIView * original)
{
    // Create a white border with defined width
    original.layer.borderColor = [UIColor yellowColor].CGColor;
    original.layer.borderWidth = 1.5;

    // Set image corner radius
    original.layer.cornerRadius =cornerRadius;

    // To enable corners to be "clipped"
    [original setClipsToBounds:YES];
    return original;
}

在obj c中通过编程实现吗

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(20, 50,    200, 200)];

view.layer.backgroundColor = [UIColor whiteColor].CGColor;
view.layer.cornerRadius = 20.0;
view.layer.frame = CGRectInset(v.layer.frame, 20, 20);

[view.layer.shadowOffset = CGSizeMake(1, 0);
view.layer.shadowColor = [[UIColor blackColor] CGColor];
view.layer.shadowRadius = 5;
view.layer.shadowOpacity = .25;][1]

[self.view addSubview:view];

我们也可以从stoaryboard做这个。

 layer.cornerRadius  Number  5

这是一种不同于Ed Marty的方法:

#import <QuartzCore/QuartzCore.h>

[v.layer setCornerRadius:25.0f];
[v.layer setMasksToBounds:YES];

你需要setMasksToBounds来从IB加载所有的对象…我有一个问题，我的视图得到了圆润，但没有IB的对象:/

这是固定的=D希望它有助于!

使用UIView扩展:

extension UIView {    

func addRoundedCornerToView(targetView : UIView?)
{
    //UIView Corner Radius
    targetView!.layer.cornerRadius = 5.0;
    targetView!.layer.masksToBounds = true

    //UIView Set up boarder
    targetView!.layer.borderColor = UIColor.yellowColor().CGColor;
    targetView!.layer.borderWidth = 3.0;

    //UIView Drop shadow
    targetView!.layer.shadowColor = UIColor.darkGrayColor().CGColor;
    targetView!.layer.shadowOffset = CGSizeMake(2.0, 2.0)
    targetView!.layer.shadowOpacity = 1.0
}
}

用法:

override func viewWillAppear(animated: Bool) {

sampleView.addRoundedCornerToView(statusBarView)

}

试试这个

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

...

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

注意:如果你试图将圆角应用到UIViewController的视图，它不应该应用在视图控制器的构造函数中，而应该应用在-viewDidLoad中，在视图实际实例化之后。

Swift 4 -使用IBDesignable

   @IBDesignable
    class DesignableView: UIView {
    }

    extension UIView
    {

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