如何在对象中保存Icollection？

Question

我有以下代码：

ICollection<Sample> samples = new Collection<Sample>();
samples.Add(sample1);
samples.Add(sample2);
Order record = scope.DbContext.Orders.AddNew(new Order
{
    Name = GenerateName("Order"),
    Samples = samples
});

当我查看样本时，它会同时包含sample1和sample2。但是，当我将它添加到Order的样品时 ，样品是空的。样品也是ICollection类型。如何将ICollections添加到空的ICollection？

---

更新

我在中间打印样本和记录时的结果：

samples
Count = 2
    [0]: {iVention.Lifescience.Test.ElectronicSignatureRepositoryTest.SignHierarchyTest.Sample one.2012-04-21 11:07:24}
    [1]: {iVention.Lifescience.Test.ElectronicSignatureRepositoryTest.SignHierarchyTest.Sample two.2012-04-21 11:07:24}
record.Samples
{System.Data.Objects.DataClasses.EntityCollection<iVention.Database.Sample>}
    [System.Data.Objects.DataClasses.EntityCollection<iVention.Database.Sample>]: {System.Data.Objects.DataClasses.EntityCollection<iVention.Database.Sample>}
    Count: 0
    IsReadOnly: false

---

更新2：

AddNew onlu添加了实体，为什么会从Samples中删除样本？

public static TEntity AddNew<TEntity>(this IDbSet<TEntity> self, object fromValues) where TEntity : class
{
    return self.Add(Create(self, fromValues));
}

在给予AddNew的object formValues中，Samples仍然包含2个样本。

添加如下所示：

public static TEntity Create<TEntity>(this IDbSet<TEntity> self, object fromValues) where TEntity : class
{
   TEntity returnValue = self.Create();
   var targetProperties = typeof(TEntity).GetProperties();
   {
   var targetProperty = targetProperties.Single(c => c.Name == property.Name);
   if (targetProperty.CanWrite && property.GetIndexParameters().Length == 0)
   {
      if (targetProperty.PropertyType.IsGenericType && targetProperty.PropertyType.GetGenericTypeDefinition() == typeof(System.Collections.Generic.ICollection<>))
      {
      }
      else
      {
         targetProperty.SetValue(returnValue, property.GetValue(fromValues, null), null);
      }
   }
   return returnValue;
}

因此当它是ICollection时，什么都不会被添加到returnValue。 returnValue中的样本为空。