iOS如何裁剪圆形头像

- (void)viewDidLoad {  [super viewDidLoad];     //加载图片  UIImage *image = [UIImage imageNamed:@"菲哥"];     //获取图片尺寸  CGSize size = image.size;     //开启位图上下文  UIGraphicsBeginImageContextWithOptions(size, NO, 0);     //创建圆形路径  UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, image.size.width, image.size.height)];     //设置为裁剪区域  [path addClip];     //绘制图片  [image drawAtPoint:CGPointZero];     //获取裁剪后的图片  _imageView.image = UIGraphicsGetImageFromCurrentImageContext();     //关闭上下文  UIGraphicsEndImageContext();   }

- (void)viewDidLoad {  [super viewDidLoad];     //加载图片  UIImage *image = [UIImage imageNamed:@"大菲哥"];     //设置边框宽度  CGFloat border = 3;  CGFloat imageWH = image.size.width;     //计算外圆的尺寸  CGFloat ovalWH = imageWH + 2 * border;     //开启上下文  UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);     //画一个大的圆形  UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, ovalWH, ovalWH)];     [[UIColor orangeColor]set];     [path fill];     //设置裁剪区域  UIBezierPath *path1 = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(border, border, imageWH, imageWH)];  [path1 addClip];     //绘制图片  [image drawAtPoint:CGPointMake(border, border)];     //从上下文中获取图片  _imageView.image = UIGraphicsGetImageFromCurrentImageContext();     //关闭上下文  UIGraphicsEndImageContext();   }

- (void)viewDidLoad {  [super viewDidLoad];     //开启上下文  UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, 0);     //获取上下文  CGContextRef ctx = UIGraphicsGetCurrentContext();     //把控件上的图层渲染到上下文  [self.view.layer renderInContext:ctx];     //获取上下文中的图片  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();     //关闭上下文  UIGraphicsEndImageContext();     //保存图片到相册  UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);   }