The Menu Control has to be one of the coolest and most frustrating controls I've worked with. Anyways, if you're here to figure out how to make your control horizontal, you've come to the right place.
To begin set your SiteMapDataSource as shown below:
<asp:SiteMapDataSource ID="SiteMapDataSource2" runat="server" ShowStartingNode="false" StartingNodeOffset="0" />
<
asp:Menu ID="Menu1" StaticDisplayLevels="2" runat="server" Orientation="Horizontal" DataSourceID="SiteMapDataSource2"></asp:Menu>
Thats it!!! ( NOTE: The trick is the StaticDisplayLevel setting not the orientation)
Here is the Web.Sitemap: everything in red is what will display in your menu
(IT should look like this)
Root A B C
<?xml version="1.0" encoding="utf-8" ?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" >
<siteMapNode>
<siteMapNode url="Default.aspx" title="Root" description="" roles="">
<siteMapNode url="A.aspx" title="A" description="" roles="">
<siteMapNode url="1.aspx" title="1" description="" roles="" />
<siteMapNode url="2.aspx" title="2" description="" roles="" />
</siteMapNode>
<siteMapNode url="B.aspx" title="B" description="" roles="">
<siteMapNode url="3.aspx" title="3" description="" roles="" />
<siteMapNode url="4.aspx" title="4" description="" roles="" />
</siteMapNode>
<siteMapNode url="C.aspx" title="C" description="" roles="">
<siteMapNode url="5.aspx" title="5" description="" roles="" />
<siteMapNode url="6.aspx" title="6" description="" roles="" />
</siteMapNode>
</siteMapNode>
</siteMapNode>
</siteMap>
If this helps you, give me a shout out.
Pete Orologas