使用C#驱动程序反序列化嵌套类时MongoDB出错

通常，当我将对象存储到集合中并向对象添加新属性时，当在mongodb中找不到该属性时，mongodb C#驱动程序将使用默认值。然而，当我有一个嵌套类时，官方的MongoDB C#驱动程序似乎不会以同样的方式处理它。请参见示例代码：

MongoCollection<Person> peopleCollection = fd.GetCollection<Person>("peopledb");
Person p = peopleCollection.FindOne(); //errors here w/ Type Cast Exception

在这种情况下，当我执行FindOneAs时，它将出错，因为Person.personAddress.state不存在

有人知道如何让反序列化程序也以同样的方式反序列化嵌套类吗？

如果您通过特定类型查找嵌套类，c#驱动程序会自动反序列化嵌套类，请使用mongo db测试下面的示例

 public ActionResult Index()
        {
         //   MongoDatabase databse = MongoDatabase.Create("mongodb://localhost:27017/BeniSoftLabs");
            MongoDatabase mongodb = DBConn.DBConn.getDBConn();
            var menu = mongodb.GetCollection<Menu>("Menu").FindOne();


   }

 public class Node
    {
        public virtual string NodeTitle { get; set; }
        public virtual string Link { get; set; }
        public virtual string IconName { get; set; }
        public virtual string ClassName { get; set; }
        public virtual IList<Node> NodeList { get; set; }

    }

 public class Menu
    {
        public virtual ObjectId id { get; set; }
        public virtual IList<Node> MenuList { get; set; }
        public virtual IList<Node> RightMenuList { get; set; }
    }

---

好的，现在尝试向节点类添加一个新属性，比如一个新的字符串属性。执行此操作时，会引发反序列化错误。

 public ActionResult Index()
        {
         //   MongoDatabase databse = MongoDatabase.Create("mongodb://localhost:27017/BeniSoftLabs");
            MongoDatabase mongodb = DBConn.DBConn.getDBConn();
            var menu = mongodb.GetCollection<Menu>("Menu").FindOne();


   }

 public class Node
    {
        public virtual string NodeTitle { get; set; }
        public virtual string Link { get; set; }
        public virtual string IconName { get; set; }
        public virtual string ClassName { get; set; }
        public virtual IList<Node> NodeList { get; set; }

    }

 public class Menu
    {
        public virtual ObjectId id { get; set; }
        public virtual IList<Node> MenuList { get; set; }
        public virtual IList<Node> RightMenuList { get; set; }
    }

{
        "_id" : ObjectId("50fecb7d60df893ad0e25138"),
        "MenuList" : [
                {
                        "NodeTitle" : "About Us",
                        "Link" : "/href.html",
                        "IconName" : "icon-home",
                        "ClassName" : "active",
                        "NodeList" : null
                },
                {
                        "NodeTitle" : "Our Solution",
                        "Link" : null,
                        "IconName" : "icon-briefcase",
                        "ClassName" : "dropdown",
                        "NodeList" : [
                                {
                                        "NodeTitle" : "HTML5 Apps",
                                        "Link" : "#/HTML5Apps",
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "CSS3 Apps",
                                        "Link" : "#/CSS3Apps",
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "Single Page Apps",
                                        "Link" : "#/SPAApps",
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "Smart Phone Apps",
                                        "Link" : "#/SMartPhoneApps",
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : ".Net Enterprise Apps",
                                        "Link" : "#/NETEnterprise",
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "Node.js Enterprise Apps",

                                        "Link" : "#/NodeEnterprise",
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                }
                        ]
                },
                {
                        "NodeTitle" : "Technologies",
                        "Link" : null,
                        "IconName" : "icon-briefcase",
                        "ClassName" : "dropdown",
                        "NodeList" : [
                                {
                                        "NodeTitle" : "HTML5 & CSS3",
                                        "Link" : null,
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "Angular.js",
                                        "Link" : null,
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "Node.js",
                                        "Link" : null,
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "Asp.net MVC",
                                        "Link" : null,
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "MongoDB",
                                        "Link" : null,
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                },
                                {
                                        "NodeTitle" : "My Sql",
                                        "Link" : null,
                                        "IconName" : null,
                                        "ClassName" : null,
                                        "NodeList" : null
                                }
                        ]
                },
                {
                        "NodeTitle" : "Why Us",
                        "Link" : null,
                        "IconName" : "icon-fire",
                        "ClassName" : null,
                        "NodeList" : null
                }
        ],
        "RightMenuList" : [
                {
                        "NodeTitle" : "Join Us",
                        "Link" : null,
                        "IconName" : "icon-eye-open",
                        "ClassName" : null,
                        "NodeList" : null
                },
                {
                        "NodeTitle" : "Contact Us",
                        "Link" : null,
                        "IconName" : "icon-user",
                        "ClassName" : null,
                        "NodeList" : null
                }
        ]
}