LINQ Select where object does not contain items from list

Question

I m struggling with LINQ syntax here   thought I d toss it out here  I cant find exactly what I m looking for anywhere else   OK  say I ve got this   public class Bar      public int BarId   get  set       public class Foo      public List lt Bar gt  BarList   get  set       List lt Foo gt  fooBunch   GetABunchOfFoos      let s just assume I m getting more than one List lt Foo gt  fooSelect   new List lt Foo gt   List lt Bar gt  filterBars   GetAFewBars      assume I m getting like 2 or 3  fooSelect    from f in fooBunch              where   from b in f BarList select b BarId  Contains ITEM FROM filterBars BarId               select f  ToList      So  long story short I want to use LINQ to filter out my list of objects based on objects from another list  I hope this makes sense  I think I m just lost on the Contains portion   I don t know how to write that

User · Answer

dump this into a more specific collection of just the ids you don't want

var notTheseBarIds = filterBars.Select(fb => fb.BarId);

then try this:

fooSelect = (from f in fooBunch
             where !notTheseBarIds.Contains(f.BarId)
             select f).ToList();

or this:

fooSelect = fooBunch.Where(f => !notTheseBarIds.Contains(f.BarId)).ToList();

User · Answer

In general  you re looking for the  Except  extension   var rejectStatus   GenerateRejectStatuses    var fullList   GenerateFullList    var rejectList   fullList Where i   gt  rejectStatus Contains i Status    var filteredList   fullList Except rejectList     In this example  GenerateRegectStatuses   should be the list of statuses you wish to reject  or in more concrete terms based on your example  a List lt int gt  of IDs

User · Answer

Try this simple LINQ     For a file list array var files   Directory GetFiles folderPath         SearchOption AllDirectories      simply use Where   x Contains var notContain   files Where x   gt    x Contains     RECYCLE BIN     ToList       Or use Except   var containing   files Where x   gt  x Contains     RECYCLE BIN     ToList        notContain   files Except containing  ToList

User · Answer

I have not tried this  so I am not guarantueeing anything  however  foreach Bar f in filterBars        search f    Foo search Bar b        fooSelect    from f in fooBunch                  where   from b in f BarList select b BarId  Contains b ID                   select f  ToList         return fooSelect

[c#] LINQ: Select where object does not contain items from list

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