Distinct in Linq query
===

How I can make this Distinct work:

     

       var blockIdMap = (from panelEntry in panelEntries
                              select new {panelEntry.BlockNo, panelEntry.BlockID})
                              .Distinct()
                              .ToDictionary(mc => mc.BlockNo , mc => mc.BlockID);

I need to have only unique entries of BlockNo with it's BlockId because I enter them to Dictionary and BlockNo should be unique.
I want just to take the first one.