I am using the new RSSDataSource control (that is in the great RSSToolKit from Dmitry Robsman) in the new ASP.NET 2.0 site I am [finally] working on [little by little] for Vermont.NET. I wanted to expose only the last 10 items from my VTdotNET and Jobs feed that I show on the home page in DataList controls. The RSSDataSource control doesn't have such a property, but it's pretty easy to do as you would for most collections.
Rather than create the RSSDataSource visually and then set it to the DataSource property of the DataList, I am doing it in code.
Programmatically, you work with the GenericRssChannel. The GenericRSSChannel contains a collection of GenericRSSElements. You can use the channel's SelectItems property, which returns the elements as a Collections.IEnumerable, but that gives you the entire feed.
Instead, I pass the GenericRssChannel that has already loaded the rss into my ItemSubset function and attach the return value to the DataList.
Dim cVTdotNET as GenericRssChannel
cVTdotNET= GenericRssChannel.LoadChannel(http://www.thedatafarm.com/blog/SyndicationService.asmx/GetRssCategory?categoryName=VTdotNETFeed)
MyDataList.DataSource=ItemSubset(cVTdotNET,10)
Private Function ItemSubset(ByVal rssC as GenericRssChannel,ByVal rssQuant as Int32) as ICollection
Dim rssItems(rssQuant-1) as GenericRSSElement
Array.Copy(rssC.Items.ToArray,rssItems, rssQuant)
Return rssItems
End Function