切割圆形头像

对UIImageView添加分类

.h

-(void) setRoundLayer;

.m

-(void) setRoundLayer {

//4步

  self.layer.masksToBounds = YES;

  self.layer.cornerRadius = self.bounds.size.width *0.5;

  self.layer.borderWidth = 2;

  self.layer.borderColor = [UIColor whiteColor].CGColor;

}