Causing a 3 row GridView to fill the available vertical space?

I have a two column, three row GridView that I would like to have fill the avail开发者_如何转开发able screen space provided by the surrounding layouts. By setting the layout_height and layout_width to "fill_parent" and the background color to red I can see that the GridView is in fact filling the space -- but the content is not.

When there is extra space, I'd like the GridView to have more verticalSpacing or horizontalSpacing to "fill up" the screen. I don't see an available setting to do that though.

There has to be an elegant way to do this, but I've yet to find it =\