Linq Select All Except items from listbox

Question

I've been struggling on a way to do this for a while. I have this a listbox in asp.net that I use that looks like :

<asp:ListBox ID="lstLinkedProspect" runat="server" SelectionMode="Multiple" />

What I want to do with it is to be able to select all items I have in a specific table, all except the one that are in the listbox. Not only the selected but all items that are already in the list. I use System.Linq.Dynamic library. Here is what I'm trying to do :

Dim lstProspect = dbConnection.Prospects.Where(If(String.IsNullOrWhiteSpace(SearchFilters.Value), "ProspectId > 0", SearchFilters.Value).ToString) _
                                                .Except(' There goes all the items in the list box)

What I have already tried is :

Dim lstProspect = dbConnection.Prospects.Where(If(String.IsNullOrWhiteSpace(SearchFilters.Value), "ProspectId > 0", SearchFilters.Value).ToString) _
                                                .Except(lstLinkedProspect.Items.Cast(Of ListItem)().Where(Function(x) x.Value).Cast(Of Beans.Prospect))

Is it possible in Linq to get all the items from a table that are not in the listbox? Note that the Value property of the ListItem in the listbox is the ProspectId.

Thanks in advance.

Answer 1

This is the the code I found to achieve what I was looking for :

Dim lstItems = dbConnection.Prospects.Where(Function(x) ids.Contains(x.ProspectId))
Dim lstProspect = dbConnection.Prospects.Where(If(String.IsNullOrWhiteSpace(SearchFilters.Value),
"ProspectId > 0", SearchFilters.Value).ToString).Except(lstItems)

Hope this can help anyone struggling with that problem.