Question

Using Entity Framework on .Net 4
Here is my code:

        using (frfcourEntities frf = new frfcourEntities())
        {
            EntityKey routehdrId = new EntityKey("frfcourEntities.Routehdrs", "Refno", "xxx");
            try{
                var routehdr = frf.GetObjectByKey(routehdrId);
                frf.DeleteObject(routehdr);
                frf.SaveChanges();
            }
            catch(System.Data.ObjectNotFoundException)
            {}
        }

The line:

catch(System.Data.ObjectNotFoundException)

will not compile. It reports

The type caught or thrown must be derived from System.Exeception. 

But ObjectNotFoundException is what the EF GetObjectByKey method throws.

Answer 1

Add an assembly reference to System.Data. Without it “using System.Data” works but it doesn’t resolve DataException.