Linq to object: ToList can not convert to generic list

Question

Dim tenItem = From t In _InvalidFeeList _
                      From i In ItemCount _
                      Where t.FeeCode <> i.FeeCode _
                      Order By t.Description _
                      Ascending Take (10)


        Dim feeList As List(Of AccessorialFee) = tenItem.ToList()

I am getting "Can not convert to System.generic.list" error. I look all over for this error and it seem like my code should work for example here

I don't get it. Can someone tell me where i got it wrong?

edit: I think i should explain what I'm trying to do here. I want to compare two object list and select the object from the InvalidFeeList if the FeeCode is not equal to the object in ItemCount FeeCode and take the first 10 objects from the InvalidFeeList.

Answer 1

_InvalidFeeList is not of type List(Of AccessorialFee)

[Edit] Try this and add a breakpoint and a watch:

Dim tenItem = (From t In _InvalidFeeList _
                      From i In ItemCount _
                      Where t.FeeCode <> i.FeeCode _
                      Order By t.Description _
                      Ascending Take (10)).ToList().GetType()

Answer 2

The problem is that you've got two "From" clauses, so the result isn't just the type of the original collection. It's easy to fix though - just add a projection at the end:

Dim tenItem = From t In _InvalidFeeList _
              From i In ItemCount _
              Where t.FeeCode <> i.FeeCode _
              Order By t.Description _
              Ascending Take (10) _
              Select t  ' This is the new line '

Dim feeList As List(Of AccessorialFee) = tenItem.ToList()

EDIT: Are you trying to find items in _InvalidFeeList whose FeeCode isn't present in any item in ItemCount? If so, I suggest this change:

Dim feeCodes = From i In ItemCount Select i.FeeCode
Dim feeCodeSet = new HashSet(Of FeeCodeType)(feeCodes)

Dim tenItem = From t in _InvalidFeeList
              Where Not feeCodeSet.Contains(t.FeeCode)
              Order By t.Description _
              Ascending Take (10) 
Dim feeList As List(Of AccessorialFee) = tenItem.ToList()

As you can see, I didn't know the type of FeeCode, and VB is not exactly my strong point, but I hope you get the general idea. This suggestion is assuming you're using LINQ to Objects - if you're using LINQ to SQL I'm not sure of the best way to do it. Note that we no longer need the Select clause for tenItem as we're only dealing with a single collection now.