Subtract a generic list from another

Question

I am trying remove a list of firmIDs from one list from another. I don\'t really understand linq but I am pretty sure I need to use it.

List firm         


        

Answer 1

From your code above, I presume you are trying to get entries from Firms that have a corresponding item in TrackedFirms.

List results = Firms.Where(f => TrackedFirms.Any(t => t.FirmId == f.FirmId)).ToList();

If on the other hand you want untracked firms, then it's :

List results = Firms.Where(f => !TrackedFirms.Any(t => t.FirmId == f.FirmId)).ToList();