很多朋友都还在2行代码切圆角吧.......
哈哈 今天放出代码 直接拖进你的项目就能用了.不用再被人家嘲笑.

直接放出2个分类,
基于SDWebImage封装

//
//  UIImageView+WebImage.swift
//
//  Created by Jonson on 17/3/13.
//

import UIKit

extension UIImage {
    
    /// 创建头像图像
    ///
    /// - parameter size:      尺寸
    /// - parameter backColor: 背景颜色
    ///
    /// - returns: 裁切后的图像
    func ht_avatarImage(size: CGSize?, backColor: UIColor = UIColor.white, lineColor: UIColor = UIColor.lightGray) -> UIImage? {
        
        var size = size
        if size == nil {
            size = self.size
        }
        let rect = CGRect(origin: CGPoint(), size: size!)
        
        UIGraphicsBeginImageContextWithOptions(rect.size, true, 0)
        
        backColor.setFill()
        UIRectFill(rect)
        
        let path = UIBezierPath(ovalIn: rect)
        path.addClip()
        
        draw(in: rect)
        
        let ovalPath = UIBezierPath(ovalIn: rect)
        ovalPath.lineWidth = 2
        lineColor.setStroke()
        ovalPath.stroke()
        
        let result = UIGraphicsGetImageFromCurrentImageContext()
        
        UIGraphicsEndImageContext()
        
        return result
    }
    
    /// 生成指定大小的不透明图象
    ///
    /// - parameter size:      尺寸
    /// - parameter backColor: 背景颜色
    ///
    /// - returns: 图像
    func ht_image(size: CGSize? = nil, backColor: UIColor = UIColor.white) -> UIImage? {
        
        var size = size
        if size == nil {
            size = self.size
        }
        let rect = CGRect(origin: CGPoint(), size: size!)
        
        UIGraphicsBeginImageContextWithOptions(rect.size, true, 0)
        
        backColor.setFill()
        UIRectFill(rect)
        
        draw(in: rect)
        
        let result = UIGraphicsGetImageFromCurrentImageContext()
        
        UIGraphicsEndImageContext()
        
        return result
    }
}

第二个

//
//  UIImageView+WebImage.swift
//
//  Created by Jonson on 17/3/13.
//

import SDWebImage

extension UIImageView {
    
    /// 隔离 SDWebImage 设置图像函数
    ///
    /// - parameter urlString:        urlString
    /// - parameter placeholderImage: 占位图像
    /// - parameter isAvatar:         是否头像
    func ht_setImage(urlString: String?, placeholderImage: UIImage?, isAvatar: Bool = false) {
        
        // 处理 URL
        guard let urlString = urlString,
            let url = URL(string: urlString) else {
            // 设置占位图像
            image = placeholderImage
            
            return
        }
        
        // 可选项只是用在 Swift，OC 有的时候用 ! 同样可以传入 nil
        sd_setImage(with: url, placeholderImage: placeholderImage, options: [], progress: nil) { [weak self] (image, _, _, _) in
            
            // 完成回调 - 判断是否是头像
            if isAvatar {
                self?.image = image?.ht_avatarImage(size: self?.bounds.size)
            }
        }
    }
}

最后调用

iconView.ht_setImage(urlString: model.image, placeholderImage: UIImage(named: "default_image"), isAvatar: true)