Nick Nick - 6 months ago 27
Vb.net Question

LINQ to Objects - Does Not Contain?

I have a collection of Items that each have a collection of Relationships. I have a list of Groups that Items can have Relationships with.

I can find all the Items that have a particular relationship but I now want to find all the Items that don't have a Relationship with any of my Groups.

I can find the Items that have a relationship with any of the Groups by doing this:

Dim groupIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList
Dim haveGroup = (From item In items _
Where item.Relationships.Any(Function(r) groupIds.Contains(r.TargetID)) _
Select item).ToList


How can I find all the items that do not have a relationship with any of the groups?

Answer

I don't remember VB all that well, but a simple "Not" should work.

Dim groupIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList
Dim haveGroup = (From item In items _
             Where Not item.Relationships.Any(Function(r) groupIds.Contains(r.TargetID)) _
             Select item).ToList