Question

I know LINQ is supposed to automatically return strongly typed result sets. When I attach an ObjectDataSource to a LINQ based method however (with no explicit return type), I don’t get access to any of the columns defined in the LINQ.

Example method:

   <System.ComponentModel.DataObjectMethod(ComponentModel.DataObjectMethodType.Select)> _
    Public Function GetMarketClusterList() As IEnumerable(Of MarketCluster)
        Return From d In db.tblMarkets
               Select New MarketCluster With {.MarketCluster = d.MarketCluster}
               Distinct
    End Function

    Public Class MarketCluster
        Public MarketCluster As String
    End Class

EDIT
I changed my code to use an explicit type and select into that. At least now I know the return type, but it doesn’t help with the original problem. Even weirder, I found with the debugger that if I do

<%# Eval(“MarketCluser”) %> it fails and says “A field or property with the name MarketCluster was not found on the selected data source”, but if I do <% Container.DataItem.MarketCluser %> it works fine!

Answer 1

The error message said the exact error, I just missed it. When it said could not find a “property”, it meant class member called “Property”. I changed my code to this and now it works perfectly.

Private _MarketCluster As String
Public Property MarketCluster As String
    Get
       Return _MarketCluster
    End Get
    Set(value As String)
       _MarketCluster = value
    End Set
End Property