IOS: crea un UIImage o UIImageView con esquinas redondeadas

¿Es posible crear una UIImageo una UIImageViewcon esquinas redondeadas? Porque quiero tomar un UIImagey mostrarlo dentro de un UIImageView, pero no sé cómo hacerlo.

Sí, es posible.
Importe el encabezado QuartzCore ( #import <QuartzCore/QuartzCore.h>) y juegue con la layerpropiedad del UIImageView.

yourImageView.layer.cornerRadius = yourRadius;
yourImageView.clipsToBounds = YES;

Consulte la referencia de la clase CALayer para obtener más información.

Pruebe este código para el marco QuartzCore de importación de imágenes redondas, una forma sencilla de crear una imagen redonda

imageView.layer.backgroundColor=[[UIColor clearColor] CGColor];
imageView.layer.cornerRadius=20;
imageView.layer.borderWidth=2.0;
imageView.layer.masksToBounds = YES;
imageView.layer.borderColor=[[UIColor redColor] CGColor];

C objetivo

-(UIImage *)makeRoundedImage:(UIImage *) image 
                      radius: (float) radius;
{
  CALayer *imageLayer = [CALayer layer];
  imageLayer.frame = CGRectMake(0, 0, image.size.width, image.size.height);
  imageLayer.contents = (id) image.CGImage;

  imageLayer.masksToBounds = YES;
  imageLayer.cornerRadius = radius;

  UIGraphicsBeginImageContext(image.size);
  [imageLayer renderInContext:UIGraphicsGetCurrentContext()];
  UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();

  return roundedImage;
}

Swift 3

func makeRoundedImage(image: UIImage, radius: Float) -> UIImage {
    var imageLayer = CALayer()
    imageLayer.frame = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)
    imageLayer.contents = image.cgImage

    imageLayer.masksToBounds = true
    imageLayer.cornerRadius = radius

    UIGraphicsBeginImageContext(image.size)
    imageLayer.render(in: UIGraphicsGetCurrentContext())
    var roundedImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return roundedImage
}

uiimageview.layer.cornerRadius = uiimageview.frame.size.height/2;
uiimageview.clipToBounds = YES;

#import <QuartzCore/QuartzCore.h>

// UIImageView+OSExt.h
#import <UIKit/UIKit.h>

@interface UIImageView (OSExt)
- (void)setBorder:(CGFloat)borderWidth color:(UIColor*)color;
@end

// UIImageView+OSExt.m
#import "UIImageView+OSExt.h"

@implementation UIImageView (OSExt)
- (void)layoutSublayersOfLayer:(CALayer *)layer
{
    for ( CALayer *sub in layer.sublayers )
    {
        if ( YES == [sub.name isEqual:@"border-shape"])
        {
            CGFloat borderHalf = floor([(CAShapeLayer*)sub lineWidth] * .5);
            sub.frame = layer.bounds;
            [sub setBounds:CGRectInset(layer.bounds, borderHalf, borderHalf)];
            [sub setPosition:CGPointMake(CGRectGetMidX(layer.bounds),
                                       CGRectGetMidY(layer.bounds))];
        }
    }
}

- (void)setBorder:(CGFloat)borderWidth color:(UIColor*)color
{
    assert(self.frame.size.width == self.frame.size.height);
    for ( CALayer *sub in [NSArray arrayWithArray:self.layer.sublayers] )
    {
        if ( YES == [sub.name isEqual:@"border-shape"])
        {
            [sub removeFromSuperlayer];
            break;
        }
    }

    CGFloat borderHalf = floor(borderWidth * .5);
    self.layer.cornerRadius = self.layer.bounds.size.width * .5;

    CAShapeLayer *circleLayer = [CAShapeLayer layer];
    self.layer.delegate = (id<CALayerDelegate>)self;
    circleLayer.name = @"border-shape";
    [circleLayer setBounds:CGRectInset(self.bounds, borderHalf, borderHalf)];
    [circleLayer setPosition:CGPointMake(CGRectGetMidX(self.layer.bounds),
                                         CGRectGetMidY(self.layer.bounds))];
    [circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:circleLayer.bounds] CGPath]];
    [circleLayer setStrokeColor:color.CGColor];
    [circleLayer setFillColor:[UIColor clearColor].CGColor];
    [circleLayer setLineWidth:borderWidth];

    {
    circleLayer.shadowOffset = CGSizeZero;
    circleLayer.shadowColor = [[UIColor whiteColor] CGColor];
    circleLayer.shadowRadius = borderWidth;
    circleLayer.shadowOpacity = .9f;
    circleLayer.shadowOffset = CGSizeZero;
    }

    // Add the sublayer to the image view's layer tree
    [self.layer addSublayer:circleLayer];

    // old variant
    //CALayer *layer = self.layer;
    //layer.masksToBounds = YES;
    //layer.cornerRadius = self.frame.size.width * 0.5;
    //layer.borderWidth = borderWidth;
    //layer.borderColor = color;
}
@end

Configuración cornerRadiusy clipsToBoundses la forma correcta de hacer esto. Sin embargo, si cambia el tamaño de la vista, el radio no se actualizará. Para obtener un comportamiento adecuado de cambio de tamaño y animación, debe crear una UIImageViewsubclase.

class RoundImageView: UIImageView {
    override var bounds: CGRect {
        get {
            return super.bounds
        }
        set {
            super.bounds = newValue
            setNeedsLayout()
        }
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        layer.cornerRadius = bounds.width / 2.0
        clipsToBounds = true
    }
}

Pruebe esto para obtener esquinas redondeadas de la vista de imagen y también para colorear las esquinas:

imageView.layer.cornerRadius = imageView.frame.size.height/2;
imageView.layer.masksToBounds = YES;
imageView.layer.borderColor = [UIColor colorWithRed:148/255. green:79/255. blue:216/255. alpha:1.0].CGColor;
imageView.layer.borderWidth=2;

Condición *: La altura y el ancho de imageView deben ser iguales para obtener esquinas redondeadas.

1. layer.cornerRadius = imageviewHeight / 2

2. layer.masksToBounds = verdadero

Es posible, pero te aconsejo que crees una imagen png transparente (máscara) con esquinas redondeadas y la coloques sobre tu imagen con UIImageView. Podría ser una solución más rápida (por ejemplo, si necesita animaciones o desplazamientos).

Aquí cómo configuro mi avatar redondeado en el centro de la vista de contenido:

-(void)setRoundedAvatar:(UIImageView *)avatarView toDiameter:(float)newSize atView:(UIView *)containedView;
{
    avatarView.layer.cornerRadius = newSize/2;
    avatarView.clipsToBounds = YES;

    avatarView.frame = CGRectMake(0, 0, newSize, newSize);
    CGPoint centerValue = CGPointMake(containView.frame.size.width/2, containedView.frame.size.height/2);
    avatarView.center = centerValue;
}

Círculo con UIBeizerPath # Swift-3 && #imageExtension

class ViewController: UIViewController {
    @IBOutlet weak var imageOutlet: UIImageView!
    override func viewDidLoad() {
        super.viewDidLoad()
        let image = UIImage(named: "IMG_0001.JPG")
        if let image = image {
            let renderimage = image.imageCroppingBezierPath(path: UIBezierPath(arcCenter: CGPoint(x:image.size.width/2,y:image.size.width/2 )  , radius: 200, startAngle: 0, endAngle:  (2 * CGFloat(M_PI) ), clockwise: true) )
                imageOutlet.image = renderimage
        }
    }
}


extension UIImage {
    func imageCroppingBezierPath(path:UIBezierPath) ->UIImage {

        let frame = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)

        //Defining a graphic context  to paint on
        UIGraphicsBeginImageContextWithOptions(self.size, false, 0.0)
        //Get the current graphics context (if it exists)
        let context = UIGraphicsGetCurrentContext()
        //save the current graphic context
        context?.saveGState()
        // clipping area
        path.addClip()
        self.draw(in: frame)

        //To extract an image from our canvas
        let image = UIGraphicsGetImageFromCurrentImageContext()
        //restore graphic context
        context?.restoreGState()
        //remove current context from stack
        UIGraphicsEndImageContext()
        return image!
    }
}

# import QuartzCore framework
imageView.layer.cornerRadius=imgvwUser.frame.size.width/2;
imageView.layer.masksToBounds = YES;

La altura y el ancho de imageView deben ser iguales para obtener esquinas redondeadas.