Question

Can I use LINQ to return an item in a collection that is the same TYPE as the items in the collection? I am a LINQ Noob trying to avoid looping.

    Dim mostRecentlyCreatedQuestionnaire As ParentQuestionnaireItem = 

CType((From P In questionnaireCollection Order By P.Metadata.CreateDate Descending).Take(1), ParentQuestionnaireItem)

I get an “unable to CAST” error when I include the CTYPE function. I kind of expected that error, but I imagine that if I coul dnot do this, LINQ’s usefulness would be diminished and therefore assume that there must be a way…

Answer 1

The reason that Take(1) doesn’t work is that Take(1) returns a IEnunmerable(Of TSource) or IQueryable(Of TSource) depending on the query, why First return an Object of Type TSource

Dim mostRecentlyCreatedQuestionnaire As ParentQuestionnaireItem = 
DirectCast((From P In questionnaireCollection Order By P.Metadata.CreateDate Descending).First, ParentQuestionnaireItem)