Arralist duplicate finder help...

This is what I have :

 int[] OutNumbers = new int[]            
 List<int> TempNumbers = new List<int>();

  if (!OutNumbers.Intersect(TempNumbers).Any())
     {
         Do something when find a duplicate
     }

I Need the reverse of this when the List Array finds a match to the int Array.. I know that the code below is wrong
just so you get the idea.

if (!TempNumbers.Intersect(TempNumbers).Any())
     {
         Do something when find a duplicate
     }

Thanks