C#反序列化XML时Controller列表为空的解决办法

问题描述 #

尝试反序列化包含3个Controller条目（每个条目下含network列表）的Networks对象，但Controller列表始终为空，已查阅相关帖子未找到解决办法。

定义的类代码 #

using System;
using System.Collections.Generic;
using System.Xml.Serialization;

namespace TestXML
{
    [Serializable()]
    [XmlRoot("Networks")]
    public class Networks
    {
        [XmlArray(ElementName = "Controller")]
        [XmlArrayItem("NetworkController")]
        public List<NetworkController> Controller { get; set; }

        [XmlAttribute("computer")]
        public string computer { get; set; }

        [XmlAttribute("GlobalFPPProxy")]
        public string GlobalFPPProxy { get; set; }

        [XmlAttribute("GlobalForceLocalIP")]
        public string GlobalForceLocalIP { get; set; }
    }

    [XmlType("NetworkController")]
    public class NetworkController
    {
        [XmlAttribute(AttributeName = "Id")]
        public string Id { get; set; }

        [XmlAttribute(AttributeName = "Name")]
        public string Name { get; set; }

        [XmlArray(ElementName = "network")]
        [XmlArrayItem("NetworkControllerNetwork")]
        public List<NetworkControllerNetwork> network { get; set; }
    }

    [XmlType("NetworkControllerNetwork")]
    public class NetworkControllerNetwork
    {
        [XmlAttribute(AttributeName = "ComPort")]
        public string ComPort { get; set; }

        [XmlAttribute("BaudRate")]
        public int BaudRate { get; set; }

        [XmlAttribute("NetworkType")]
        public string NetworkType { get; set; }

        [XmlAttribute("MaxChannels")]
        public int MaxChannels { get; set; }
    }
}

反序列化代码 #

private readonly string xml = @"<Networks computer=""DESKTOP-281OHFP"" GlobalFPPProxy=""GlobalFPPProxy"" GlobalForceLocalIP=""GlobalForceLocalIP"">
    <Controller Id=""100"" Name=""Falcon F4V3 1"">
        <network ComPort=""192.168.1.254"" BaudRate=""100"" NetworkType=""E131"" MaxChannels=""512""/>
        <network ComPort=""192.168.1.254"" BaudRate=""101"" NetworkType=""E131"" MaxChannels=""512""/>
        <network ComPort=""192.168.1.254"" BaudRate=""102"" NetworkType=""E131"" MaxChannels=""512""/>
        <network ComPort=""192.168.1.254"" BaudRate=""103"" NetworkType=""E131"" MaxChannels=""512""/>
        <network ComPort=""192.168.1.254"" BaudRate=""104"" NetworkType=""E131"" MaxChannels=""512""/>
        <network ComPort=""192.168.1.254"" BaudRate=""105"" NetworkType=""E131"" MaxChannels=""512""/>
    </Controller>
    <Controller Id=""1"" Name=""Serial_"">
        <network ComPort=""COM4"" BaudRate=""250000"" NetworkType=""DMX"" MaxChannels=""1""/>
    </Controller>
    <Controller Id=""2"" Name=""Null_"">
        <network NetworkType=""NULL"" MaxChannels=""1""/>
    </Controller>
</Networks>
 ";

private void GenerateXML_Click(object sender, EventArgs e)
{
    Networks result = new();
    string inputString = xml; 

    XmlDocument doc = new ();
    doc.LoadXml(inputString);

    XmlSerializer serializer = new (typeof(Networks));
    StringReader rdr = new(doc.InnerXml);
    if (rdr is not null)
    {
        if (serializer is not null)
            result = serializer.Deserialize(rdr) as Networks;
            //richTextBox1.Text = result.Controller.ToString();
        rdr.Close();
    }
}

问题原因及修复方案 #

1. 修正Networks类的Controller属性序列化特性 #

当前代码使用[XmlArray]和[XmlArrayItem]，这要求XML结构为<Controller><NetworkController>...</NetworkController></Controller>，但你的XML是直接将多个<Controller>作为Networks的子节点，没有外层数组容器。需替换为[XmlElement]：

// 替换原XmlArray相关特性
[XmlElement("Controller")]
public List<NetworkController> Controller { get; set; }

2. 修正NetworkController类的network属性序列化特性 #

同理，XML中每个Controller下是直接的多个<network>节点，无外层容器，需替换特性：

// 替换原XmlArray相关特性
[XmlElement("network")]
public List<NetworkControllerNetwork> network { get; set; }

3. 简化反序列化代码（可选） #

无需先加载XmlDocument，直接读取原始字符串即可，同时使用using自动释放资源：

private void GenerateXML_Click(object sender, EventArgs e)
{
    Networks result;
    XmlSerializer serializer = new(typeof(Networks));
    using (StringReader rdr = new StringReader(xml))
    {
        result = serializer.Deserialize(rdr) as Networks;
    }
    // 验证：此时result.Controller.Count应为3
}

额外注意事项 #

• XML节点/属性名称与类属性名称需严格匹配（大小写敏感）
• 若XML中存在可能缺失的数值属性（如部分network节点无BaudRate），建议将对应属性改为可空类型int?，避免反序列化抛出异常

内容的提问来源于stack exchange，提问作者SS4077