c#反序列化XML嵌套集合

嗨，我有一些XML希望使用XMLSerializer 将其取消序列化到.NET POCO

xml如下所示：

<?xml version="1.0" encoding="UTF-8"?>
  <message uuid="{2f1e274c-6a53-afea-3047-6dc739539656}">
    <envelope received="a_date" subject="a_name">
      <from>
        <monitor name="Local Folder" user_description="" uuid="{668DC658-97D7-42c8-AE72-ED289DD02355}"/>
      </from>
      <to>
        <account>
          <factory name="a_name"/>
        </account>
      </to>
    </envelope>
    <status>
      <action name="Folder" occured="a_date" type="monitor">
        <session completed="a_date" name="a_name" started="a_date"/>
      </action>
      <action occured="a_date" type="monitor"/>
      <action occured="a_date" type="translate">
        <session completed="a_date" current="a_number" name="a_name" started="a_date" total="a_number" unit="time"/>
        <session completed="a_date" current="a_number" name="a_name" started="a_date" total="a_number" unit="time"/>
      </action>
      <action occured="a_date" type="deliver">
        <session completed="a_date" current="a_number" name="a_name" started="a_date" total="a_number" unit="byte"/>
        <session completed="a_date" name="a_name" started="a_date" unit="byte"/>
        <session completed="a_date" current="a_number" name="a_name" started="a_date" total="a_number" unit="byte"/>
      </action>
      <action occured="a_date" type="complete"/>
    </status>
    <host name="a_name"/>
</message>

在xml中，我有一个包含操作集合的状态部分，每个操作可能包含会话集合。

我已经为XMLSerializer创建了类来反序列化xml:

namespace myNameSpace
{
    [XmlRoot("message")]
    public class message
    {
        [XmlAttribute("uuid")] 
        public string uuid { get; set; }
        [XmlElement("envelope")]
        public envelope envelope { get; set; }
        [XmlArray("status")]
        [XmlArrayItem(typeof(action))]
        public ObservableCollection<action> status { get; set; }
        [XmlElement("host")]
        public host host { get; set; }
    }
    public class envelope
    {
        [XmlAttribute("received")] 
        public string received { get; set; }
        [XmlAttribute("subject")]
        public string subject { get; set; }
        [XmlElement("from")]
        public from from { get; set; }
        [XmlElement("to")]
        public to to { get; set; }
    }
    #region envelope element definitions
    public class from
    {
        [XmlElement("monitor")]
        public monitor monitor { get; set; }
    }
    public class monitor
    {
        [XmlAttribute("name")]
        public string name { get; set; }
        [XmlAttribute("user_description")]
        public string user_description { get; set; }
        [XmlAttribute("uuid")]
        public string uuid { get; set; }
    }
    public class to
    {
        [XmlElementAttribute("account")]
        public account account { get; set; }
    }
    public class account
    {
        [XmlElementAttribute("factory")]
        public factory factory { get; set; }
    }
    public class factory
    {
        [XmlAttribute("name")]
        public string name { get; set; }
    }
    #endregion
    public class action
    {
        [XmlAttribute("name")]
        public string name { get; set; }
        [XmlAttribute("occured")]
        public string occured { get; set; }
        [XmlAttribute("type")]
        public string type { get; set; }
        [XmlArray("action")]
        [XmlArrayItem(typeof(session))]
        public ObservableCollection<session> session { get; set; }
    }
    public class session
    {
        [XmlAttribute("completed")]
        public string completed { get; set; }
        [XmlAttribute("current")]
        public long current { get; set; }
        [XmlAttribute("name")]
        public string name { get; set; }
        [XmlAttribute("started")]
        public string started { get; set; }
        [XmlAttribute("total")]
        public long total { get; set; }
        [XmlAttribute("unit")]
        public string unit { get; set; }
    }
    public class host
    {
        [XmlAttribute("name")]
        public string name { get; set; }
    }
}

大多数情况下，我得到了我想要的对象图，所有的值都被正确地反序列化了，但我找不到一种方法来让XMLSerializer反序列化action元素中的会话集合——总是空的。

有人知道我如何构建我的POCO，以便XMLserializer可以创建会话集合吗？

向致以最良好的问候

约翰。