Changing datarows appearance at databind NOT CSS

[JemPower]

I'm trying to make the entire row of a datagrid a particular style, that
been a 1px white border at the top, and a 1px black border at the bottom.

I've tried using style sheets, which simply didn't work at all. I've
managed to create some awful code that changes the appearance of each and
every cell, but I can only make the entire border a particular colour, there
doesn't seem to be a grid.border.topline / grid.border.bottomline command
like there is in CSS's.

Ideally, I'd like to be able to make the entire row have a 1px white border
at the top, and a 1px black border at the bottom, and process this at
runtime.

Has anyone got any solution to this.