UIImageView中的边框

[imageView.layer setBorderColor: [[UIColor whiteColor] CGColor]];
[imageView.layer setBorderWidth: 2.0];

[imageView.layer setShadowOffset:CGSizeMake(-1.0, -1.0)];
[imageView.layer setShadowOpacity:0.5];

imageView.layer.shadowOpacity=0.6;
imageView.layer.shadowRadius = 0.0;
imageView.layer.shadowColor = [UIColor grayColor].CGColor;
imageView.layer.shadowOffset = CGSizeMake(-2.0, 1.0);