Hi, 

There isn't a built in mechanism for resizing rows in the UI of the IGGridView. Although i suppose you could implement your own. The IGGridViewDelegate exposes a mode called ResolveRowHeight, which asks for the height of each row in the IGGridView, instead of setting a single height for all rows. 

public class GriDelegate : IGGridViewDelegate
    {
        public  override float ResolveRowHeight(IGGridView gridView, IGRowPath path)
        {
            return 20;
        }
    }

So you could potentially add a gesture, and store a dictionary of heights based on a row's path, or index. Then, if you invoke UpdateData on the gridView, it would in turn cause the REsolveRowHeight method to be invoked again, and thus adjust your heights. 

Also, it may be worth noting that in the newly released 14.1 version, the IGGridViewDataSourceHelper offers an option where row height's can auto size based on their content. 

-SteveZ