CALayer: add a border only at one side

I can add a border to a CALayer in this way:

[webView.layer setBorderColor: [[UIColor colorWithRed:0.6 green:0.7 blue:0.2 alpha:1] CGColor]];
[webView.layer setBorderWidth: 2.75];   

But is it possible to add a border only at one side? I only need a border at the bottom. Or can I reach this with other properties, e.g. frame, bounds, mask, ...?

Thanks for your help!

@Control-V

        UIWebView *webView = [[UIWebView alloc] init];
        CALayer *webViewLayer = webView.layer;

        // now you can do a lot of stuff like borders:
        [webViewLayer setBorderColor: [[UIColor greenColor] CGColor]];
        [webViewLayer setBorderWidth: 2.75];    

Have a look at the CALayer documentation: https://developer.apple.com/documentation/quartzcore/calayer

And have a look here: http://iosdevelopertips.com/cocoa/add-rounded-corners-and-border-to-uiwebview.html

I made a right border using this:

leftScrollView.clipsToBounds = YES;

CALayer *rightBorder = [CALayer layer];
rightBorder.borderColor = [UIColor darkGrayColor].CGColor;
rightBorder.borderWidth = 1;
rightBorder.frame = CGRectMake(-1, -1, CGRectGetWidth(leftScrollView.frame), CGRectGetHeight(leftScrollView.frame)+2);

[leftScrollView.layer addSublayer:rightBorder];

The easiest way is to add a subLayer that will draw the selective borders, but there are some things to consider when choosing this solution, the biggest are making sure that the borders subLayer is always on top, and that the borders change when you change the frame of your layer.

I implemented a drop in open source solution that takes care of those issues, and let you declare selective borders like this:

myView.borderDirection = AUIFlexibleBordersDirectionRight | AUIFlexibleBordersDirectionTop;

You can get the code, and read about it some more here