Hello!

I am using Entity Framework in my application.

I implemented with the partial class of an entity the IEquatable<T> interface:

Partial Class Address : Implements IEquatable(Of Address) 'Other part generated
  Public Overloads Function Equals(ByVal other As Address) As Boolean _
      Implements System.IEquatable(Of Address).Equals
    If ReferenceEquals(Me, other) Then Return True
    Return AddressId = other.AddressId
  End Function

  Public Overrides Function Equals(ByVal obj As Object) As Boolean
    If obj Is Nothing Then Return MyBase.Equals(obj)
    If TypeOf obj Is Address Then 
      Return Equals(DirectCast(obj, Address)) 
  Else
    Return False
  End Function

  Public Overrides Function GetHashCode() As Integer
    Return AddressId.GetHashCode
  End Function
End Class

Now in my code I use it this way:

Sub Main()
  Using e As New CompleteKitchenEntities
    Dim job = e.Job.FirstOrDefault
    Dim address As New Address()

    job.Addresses.Add(address)
    Dim contains1 = job.Addresses.Contains(address) 'True
    e.SaveChanges()
    Dim contains2 = job.Addresses.Contains(address) 'False

    'The problem is that I can't remove it:
    Dim removed = job.Addresses.Remoeve(address) 'False

  End Using
End Sub

Note (I checked in the debugger visualizer) that the EntityCollection class stores its entities in HashSet so it has to do with the GetHashCode function, I want it to depend on the ID so entities are compared by their IDs.

The problem is that when I hit save, the ID changes from 0 to its db value. So the question is how can I have an equatable object, being properly hashed.

Please help me find what's wrong in the GetHashCode function (by ID) and what can I change to make it work.

Thanks a lot.