Problem with linq code

AdamPembs · April 13th, 2010, 11:23 AM

Hi, Im trying to return the 3 most recent articles from a newsarticle table but getting an error "Data source is an invalid type. It must be either an IListSource, IEnumerable, or IDataSource." I want to populate 3 DetailsView controls. The intellisense shows nothing as wrong, I have created the diagram and the ptpDataContext class. Any idea where Im going wrong?

Code:

 
  Using ptpDataContext As New ptpDataContext()

Dim latest = (From r In ptpDataContext.tblNewsArticles Order By r.ArticleID Descending Select r).First()

Dim secondLatest = (From r In ptpDataContext.tblNewsArticles Order By r.ArticleID Descending Select r).Skip(1).Take(1)

Dim thirdLatest = (From r In ptpDataContext.tblNewsArticles Order By r.ArticleID Descending Select r).Skip(2).Take(1)

DetailsView1.DataSource = latest
DetailsView1.DataBind()

DetailsView2.DataSource = secondLatest 
DetailsView2.DataBind()

DetailsView3.DataSource = thirdLatest 
DetailsView3.DataBind()

        End Using

Imar · April 13th, 2010, 01:28 PM

Hi there,

Is this related to my book somehow? If not, you're better off posting in a more general ASP.NET fourm. That keeps this forum a bit cleaner, and gives you more views and potential answers: http://p2p.wrox.com/asp-net-3-5-436/

If it is related, can you specify page and/or chapter numbers?

That said: First() returns a single item, while the DataSource control expects a collection of items. Although the DetailsView presents one item at a time, it's designed to work with multiple items.

Cheers,

Imar

AdamPembs · April 13th, 2010, 05:24 PM

Ok sorry, Imar. I was using writing my own code based on code from your book's linq chapter p436, but have just got what I needed by looking at the code behind of the /reviews/view-details.aspx code behind. I'll use the correct forum in future

Imar · April 13th, 2010, 05:33 PM

No problem. Glad to hear you found what you needed.

Cheers,

Imar