圆形图片（个人头像）

 //圆形图片

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(50, 50, 150.0, 150.0)];

    //设置圆角

    imageView.layer.cornerRadius = imageView.frame.size.height/2;

    //设置遮罩

    imageView.layer.masksToBounds = YES;

    //设置内容填充模式

    [imageView setContentMode:UIViewContentModeScaleAspectFill];

    //设置超出部分剪切

    [imageView setClipsToBounds:YES];

    //设置阴影颜色

    imageView.layer.shadowColor = [UIColor whiteColor].CGColor;

    //设置阴影偏移

    imageView.layer.shadowOffset = CGSizeMake(4.0, 4.0);

    //设置阴影透明度

    imageView.layer.shadowOpacity = 0.5;

    //设置阴影角度

    imageView.layer.shadowRadius = 2.0;

    //设置边颜色

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

    //设置边的宽度

    imageView.layer.borderWidth = 2.0f;

    imageView.image = [UIImage imageNamed:@"profileIcon.jpg"];

    [self.view addSubview:imageView];