UIImageView 圆角

OC 版本：
创建UIImageView 分类：

xxx.m
@implementation UIImage (ImageCIr)

/** 设置圆形图片(放到分类中使用) */
+ (nullable UIImage *)clipCircleImageWithImage:(nullable UIImage *)image circleRect:(CGRect)rect {
    //1、开启上下文
    UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);
    
    //2、设置裁剪区域
    UIBezierPath * path = [UIBezierPath bezierPathWithOvalInRect:rect];
    [path addClip];
    
    //3、绘制图片
    [image drawAtPoint:CGPointZero];
    
    //4、获取新图片
    UIImage * newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    //5、关闭上下文
    UIGraphicsEndImageContext();
    
    //6、返回新图片
    return newImage;
}

xxx.h
+ (nullable UIImage *)clipCircleImageWithImage:(nullable UIImage *)image circleRect:(CGRect)rect;

使用:

UIImageView *roundImg = [[UIImageView alloc] initWithFrame:CGRectMake(0, 64, 200, 200)];
 
    UIImage *image = [UIImage imageNamed:@"zzz"];
    roundImg.image = [UIImage clipCircleImageWithImage:image circleRect:roundImg.frame];
    
    [self.view addSubview:roundImg];

Swift版本：

extension UIImageView {

   /// 图片切成圆形
   ///
   /// - Parameters:
   ///   - image: 传入处理的图片
   ///   - rect: 切割的大小
   /// - Returns: 返回切割的t圆形图片
   func clipCircleImage(with image: UIImage?, circleRect rect: CGRect) -> UIImage? {
       //1、开启上下文
       UIGraphicsBeginImageContextWithOptions(image?.size ?? CGSize.zero, false, 0)
       
       //2、设置裁剪区域
       let path = UIBezierPath(ovalIn: rect)
       path.addClip()
       
       //3、绘制图片
       image?.draw(at: CGPoint.zero)
       
       //4、获取新图片
       let newImage: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
       
       //5、关闭上下文
       UIGraphicsEndImageContext()
       
       //6、返回新图片
       return newImage
   }

}

调用：

let img = UIImageView.init(frame: CGRect.init(x: 0, y: 64, width: 200, height: 200))
        let customImg = UIImage.init(named: "aaa")
        
        img.image = img.clipCircleImage(with: customImg, circleRect: CGRect(x: 0, y: 0, width: img.frame.width, height: img.frame.height))
        view.addSubview(img)