用类将xml转换为c#中的分层数据

我有一个类，它从数据库中获取数据，并以分层数据的形式获取as-xml数据。

以下是数据示例：

<SecurityGroups>
<SecurityGroup>
    <Id>1</Id>
    <Name>View</Name>
</SecurityGroup>
<SecurityGroup>
    <Id>2</Id>
    <Name>Fill</Name>
    <SecurityUsers>
        <SecurityUser>
            <securityId>2</securityId>
            <userId>2</userId>
            <username>Fill</username>
        </SecurityUser>
        <SecurityUser>
            <securityId>2</securityId>
            <userId>3</userId>
            <username>FillOne</username>
        </SecurityUser>
        <SecurityUser>
            <securityId>2</securityId>
            <userId>4</userId>
        <username/></SecurityUser>
    </SecurityUsers>
</SecurityGroup>
<SecurityGroup>
    <Id>3</Id>
    <Name>Update</Name>
    <SecurityUsers>
        <SecurityUser>
            <securityId>3</securityId>
            <userId>5</userId>
            <username>Update</username>
        </SecurityUser>
        <SecurityUser>
            <securityId>3</securityId>
            <userId>6</userId>
            <username>UpdateOne</username>
        </SecurityUser>
    </SecurityUsers>
</SecurityGroup>
<SecurityGroup>
    <Id>4</Id>
    <Name>Admin</Name>
    <SecurityUsers>
        <SecurityUser>
            <securityId>4</securityId>
            <userId>1</userId>
            <username>JTays</username>
        </SecurityUser>
    </SecurityUsers>
</SecurityGroup>

效果很好！现在，我有一个类，它使用反射将xml转换为我最终将在树视图中使用的模型。下面是全班同学。

型号有：

[XmlRootAttribute(Namespace = "", IsNullable = false)]
public class SecurityGroup
{
    [XmlElementAttribute(Form = XmlSchemaForm.Unqualified)]
    public int Id { get; set; }
    [XmlElementAttribute(Form = XmlSchemaForm.Unqualified)]
    public string Name { get; set; }
    [XmlElementAttribute("SecurityUser",
        Form = XmlSchemaForm.Unqualified)]
    public List<SecurityUser> SecurityUsers { get; set; }
}
public class SecurityUser:IEntity
{
    [XmlElement(Form = XmlSchemaForm.Unqualified)]
    public int SecurityId { get; set; }
    [XmlElementAttribute(Form = XmlSchemaForm.Unqualified)]
    public int UserId { get; set; }
    [XmlElementAttribute(Form = XmlSchemaForm.Unqualified)]
    public string Username { get; set; }
    public int Id { get; set; }
}

这是转换的类。

    public class AdminManager : IAdminService
{
    public IEnumerable<SecurityGroup> SecurityGroups()
    {
        IEnumerable<SecurityGroup> list = null;
        XmlDocument xmlDoc = new XmlDocument();
        using (var c = new FMContext())
        {
            var xmlData = c.Database.SqlQuery<string>("AllSecurtyUsersProc").FirstOrDefault();
            if (xmlData != null)
            {
                xmlDoc.LoadXml(xmlData);
                list = ConvertXmlToClass<SecurityGroup>(xmlDoc, "/SecurityGroups/SecurityGroup");
            }
        }
        return list;
    }
    public static IEnumerable<T> ConvertXmlToClass<T>( XmlDocument doc, string nodeString)
        where T:class, new()
    {
        var xmlNodes = doc.SelectNodes(nodeString);
        List<T> list = new List<T>();
        foreach (XmlNode node in xmlNodes)
        {
            var item = GetNewItem<T>(node);
            list.Add(item);
        }
        return list;
    }
    public static T GetNewItem<T>(XmlNode node)
        where T:class, new()
    {
        var type = typeof (T);
        var item = new T();
        var properties = type.GetProperties();
        foreach (var property in properties)
        {
            var propertyType = property.PropertyType;
            var propertyName = property.Name;
            object value = null;
            if (IsEnumerable(property))
            {
                value = GetNodeCollectionValue(property,node);
            }
            else
            {
                value = GetNodeValue(node, propertyName);
            }
            if (value!=null)
            {
                property.SetValue(item, Convert.ChangeType(value, propertyType), null);
            }
        }
        return item;
    }
    private static object GetNodeCollectionValue(PropertyInfo property, XmlNode node)
    {
        var doc = new XmlDocument();
        var itemType = property.PropertyType.GenericTypeArguments[0];
        var xml = $"<{property.Name}><{itemType.Name}>{node.InnerXml}</{itemType.Name}></{property.Name}>";
        doc.LoadXml(xml);
        if (itemType != null)
        {
            var type = typeof (AdminManager);
            var methodInfo = type.GetMethod("ConvertXmlToClass");
            if (methodInfo!=null)
            {
                var method = methodInfo.MakeGenericMethod(itemType);
                if (method != null)
                {
                    object[] args = {doc, property.Name};
                    object result = method.Invoke(null, args);
                    return result;
                }
            }
        }
        return new object();
    }

    private static bool IsEnumerable(PropertyInfo property)
    {
        var type = property.PropertyType;
        return typeof (IEnumerable).IsAssignableFrom(type) && type.IsGenericType;
    }
    private static object GetNodeValue(XmlNode node, string nodeName)
    {
        var i = node[nodeName]?.InnerText;
        return i ?? null;
    }
}

好吧，现在是我的问题。我的问题是，当它转换时，它没有得到SecurtyUsers类的正确数据，它将它们作为对象添加，但所有内容都为null或0。有人能帮我弄清楚我去哪儿了吗？