You can determine the outer bounds of the elements you want to display and set that to the window rect. For example, with the states sample if I call this on imported:

private void usaLayer_Imported(object sender, MapLayerImportEventArgs e)
        {
            double minY = double.MaxValue;
            double maxY = double.MinValue;
            double minX = double.MaxValue;
            double maxX = double.MinValue;

            foreach (MapElement ele in (sender as MapLayer).Elements)
            {
                if (ele.Name == "Iowa" || ele.Name == "Indiana")
                {
                    minY = Math.Min(minY, ele.WorldRect.Top);
                    maxY = Math.Max(maxY, ele.WorldRect.Bottom);
                    minX = Math.Min(minX, ele.WorldRect.Left);
                    maxX = Math.Max(maxX, ele.WorldRect.Right);
                }
            }

            if ((sender as MapLayer).Elements.Count > 0)
            {
                theMap.WindowRect = new Rect(minX, minY, maxX - minX, maxY - minY);
            }
        }

It will snap the screen to contain Iowa and Indiana.

-Graham

Hello,

I am using SQL Server 2008 spatial to map US Counties. I tried using your code to determine outer bounds of the elements, but all of the elements have the same WorldRect value. The value is the same as the WorldRect value for the map. Any idea why this is happening?

I am using SQL Server 2008 spatial to map PA Counties. 

Thanks!

Jason