原圖：

圓形圖片裁剪效果：

裁剪成帶邊框的圓形圖片：

核心程式碼：

#import <UIKit/UIKit.h>

@interface UIImage (image)

/**
 *  生成一張圓形圖片
 *
 *  @param image       要裁剪的圖片
 *
 *  @return 生成的圓形圖片
 */

+ (UIImage *)imageWithClipImage:(UIImage *)image;

/**
 *  生成一張帶有邊框的圓形圖片
 *
 *  @param borderW     邊框寬度
 *  @param borderColor 邊框顏色
 *  @param
 
 image       要新增邊框的圖片
 *
 *  @return 生成的帶有邊框的圓形圖片
 */
+ (UIImage *)imageWithBorder:(CGFloat)borderW color:(UIColor *)borderColor image:(UIImage *)image;

@end

#import "UIImage+image.h"

@implementation UIImage (image)

+ (UIImage *)imageWithClipImage:(UIImage *)image{
+ 
    //1.開啟跟原始圖片一樣大小的上下文
    UIGraphicsBeginImageContextWithOptions(image
 
.size, NO, 0);
    //2.設定一個圓形裁剪區域
    //2.1繪製一個圓形
    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
    //2.2.把圓形的路徑設定成裁剪區域
    [path addClip];//超過裁剪區域以外的內容都給裁剪掉
    //3.把圖片繪製到上下文當中(超過裁剪區域以外的內容都給裁剪掉)
    [image drawAtPoint:CGPointZero];
    //4.從上下文當中取出圖片
 

    UIImage *newImage =  UIGraphicsGetImageFromCurrentImageContext();
    //5.關閉上下文
    UIGraphicsEndImageContext();

    return newImage;
}

+ (UIImage *)imageWithBorder:(CGFloat)borderW color:(UIColor *)borderColor image:(UIImage *)image{

    //1.開啟一個上下文
    CGSize size = CGSizeMake(image.size.width + 2 * borderW, image.size.height + 2 * borderW);
    UIGraphicsBeginImageContextWithOptions(size, NO, 0);
    //2.繪製大圓,顯示出來
    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, size.width, size.height)];
    [borderColor set];
    [path fill];
    //3.繪製一個小圓,把小圓設定成裁剪區域
    UIBezierPath *clipPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(borderW, borderW, image.size.width, image.size.height)];
    [clipPath addClip];
    //4.把圖片繪製到上下文當中
    [image drawAtPoint:CGPointMake(borderW, borderW)];
    //5.從上下文當中取出圖片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    //6.關閉上下文
    UIGraphicsEndImageContext();

    return newImage;
}