C# 基于类将数据存储到列表中的列表中

假设我有以下课程：

public class name()
{ 
   public string FirstName{ get; set; }
   public string LastName{ get; set; }

   public List<ItemOwner> ItemOwners { get; set; }

   public name()
   {
      this.ItemOwners = new List<ItemOwner>();
   }
} 
public class ItemOwner()
{ 
   public string nameofcat { get; set; }
   public string nameofsomething { get; set; }

   public List<AddressofCat> AddressofCats{ get; set; }

   public ItemOwner()
   {
      this.AddressofCats = new List<AddressofCat>();
   }
} 
public class AddressofCat()
{ 
   public string streetaddress{ get; set; }
   public string country { get; set; }

} 

我现在想在名单上再加一个地址：

 var newcataddress = new AddressofCat();
 newcataddress.streetaddress = "Randomaddress";
 newcataddress.country = "Rhodesia";

现在我们有了一个新的cat地址列表，我想将它们添加到返回的catobject中

---

如何执行此操作？

如果returnedcatobject的类型为

List

，则如下所示：

 var newcataddress = new AddressofCat();
 newcataddress.streetaddress = "Randomaddress";
 newcataddress.country = "Rhodesia";

returnedcatobject.Add(newcataddress);

---

什么类型的

returnedcatobject

是？dbI中的类对象正在调用mongo db，返回的对象是基于类的数据库中的对象…@user1264626:确切地说是什么类？Post-its declaration.var returnedcatobject==repo.Single（c=>c.nameofcat==“sam”）；

 var newcataddress = new AddressofCat();
 newcataddress.streetaddress = "Randomaddress";
 newcataddress.country = "Rhodesia";

returnedcatobject.Add(newcataddress);