Add border to bottom of .xib (objective-c)

Question

I am trying to only add a border to the bottom of my .xib view. I currently have the following code which places a red border on ALL FOUR sides. I only want the border to be on ONE side, the bottom... How do I set the border to the bottom?

Current Code for class that controls .xib:

- (void)awakeFromNib {

    self.contentView.layer.borderWidth  = 5.0f;
    self.contentView.layer.masksToBounds = YES;
    self.contentView.layer.borderColor  = [UIColor redColor].CGColor;
}

This is what I get:

Answer 1

如果您不知道如何制作在底部绘制红色边框的视图，那么为什么不制作一个红色子视图并将其固定在底部呢？

Answer 2

  CALayer *bottomBorder = [CALayer layer];
  bottomBorder.borderColor = [UIColor redColor].CGColor;
  bottomBorder.borderWidth = 1;
  bottomBorder.frame       = CGRectMake(0, self.contentView.frame.size.height - bottomBorder.borderWidth, self.contentView.frame.size.width, bottomBorder.borderWidth);
  [self.contentView.layer addSublayer:bottomBorder];