IOS:把用户上传头像裁剪为圆形

直接上代码：

UIImage*image =[UIImage imageNamed:@"testPic"];

//图片的宽度和高度

CGFloat imageWH = image.size.width;

//设置圆环的宽度

CGFloat border = 3;

//圆形的宽度和高度

CGFloat ovalWH = imageWH +2* border;

// 1.开启上下文

UIGraphicsBeginImageContextWithOptions(CGSizeMake(ovalWH, ovalWH),NO,0);

// 2.画大圆

UIBezierPath*path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0,0, ovalWH, ovalWH)];

//圆环颜色

[[UIColor redColor] set];

[path fill];

// 3.设置裁剪区域

UIBezierPath *clipPath =[UIBezierPath bezierPathWithOvalInRect:CGRectMake(border, border, imageWH, imageWH)];

[clipPath addClip];

// 4.绘制图片

[image drawAtPoint:CGPointMake(border, border)];

// 5.获取图片

UIImage *clipImage =UIGraphicsGetImageFromCurrentImageContext();

// 6.关闭上下文

UIGraphicsEndImageContext();

border:这是图片四周的圆环宽度

[[UIColor redColor] set];这是设置圆环颜色

clipImage 就是获取的裁剪好的图片