C#: EF Save Event Handler

gistfile1.cs

public override int SaveChanges(SaveOptions options)
{

    foreach (ObjectStateEntry entry in
        ObjectStateManager.GetObjectStateEntries(
        EntityState.Added | EntityState.Modified))
    {
        // Validate the objects in the Added and Modified state
        // if the validation fails throw an exeption.
    }
    return base.SaveChanges(options);
}