使用不同类型的行反序列化 XML C#

Question

Have a problem with deserialization XML. Can not understand how make property data different based on xml attribute id xds generate one common property data that combine properties from data UserInfo + data UserTransactions

Tried solution from this thread but have no luck Xml Example:

<?xml version="1.0" encoding="UTF-8"?>
<document>
  <data id="UserInfo">
    <rows>
      <row id="123" Name="Alex" phone="+1234567890"></row>
      <row id="321" Name="Sally" phone="+1234567890"></row>
    <rows>
  </data>
  <data id="UserTransactions">
    <rows>
      <row UserId="123" amount="100.1" date="2022-07-03"></row>
      <row UserId="123" amount="-100.1" date="2022-07-03"></row>
      <row UserId="321" amount="1" date="2022-07-03"></row>
    <rows>
  </data>
</document>

Question: Is it possible to deserialize to some class what will have properties based on xml attributes? For example some like:

    public class document
    {
        // based on <data id='UserInfo'>
        public UserInfoRow[] dataUserInfos { get; set; }
        // based on <data id='UserTransaction'>
        public UserTransactionRow[] dataUserTransactions { get; set; }
    }

Code that i'm tried

namespace test
{
    public class document
    {
        [XmlElement("data")]
        public documentData[] data { get; set; }
    }
    public class documentData
    {
        [XmlAttribute("id")]
        public string id { get; set; }

        [XmlArray("rows")]
        [XmlArrayItem("row")]
        public row[] rows { get; set; }
    }

    [XmlInclude(typeof(UserInfoRow)), XmlInclude(typeof(UserTransactionRow))]
    public class row { }
    public class UserInfoRow : row
    {
        [XmlAttribute("id")]
        public string id { get; set; }
        [XmlAttribute("Name")]
        public string Name { get; set; }
        [XmlAttribute("phone")]
        public string phone { get; set; }
    }
    public class UserTransactionRow : row
    {
        [XmlAttribute("UserId")]
        public string UserId { get; set; }
        [XmlAttribute("amount")]
        public string amount { get; set; }
        [XmlAttribute("date")]
        public string date { get; set; }
    }
}

No info from end classes

Answer 1

You cannot use an inherited class with your xml. Inherited classes requires a type attribute in the xml. Instead you can use a custom IXmlSerialize like code below

using System;
using System.Linq;
using System.Text;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Xml;
using System.Xml.Serialization;
using System.Xml.Schema;

namespace ConsoleApp2
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XmlReaderSettings settings = new XmlReaderSettings();
            settings.IgnoreWhitespace = true;
            XmlReader reader = XmlReader.Create(FILENAME);
            XmlSerializer serializer = new XmlSerializer(typeof(test.document));
            test.document doc = (test.document)serializer.Deserialize(reader);
 

        }

    }
 
}
namespace test
{
    public class document
    {        
        [XmlElement("data")]
        public documentData[] data { get; set; }
    }
    public class documentData : IXmlSerializable
    {
        [XmlAttribute("id")]
        public string id { get; set; }

        public List<UserInfoRow> userInfoRows { get; set; }
        public List<UserTransactionRow> userTransactionRows { get; set; }

        public void WriteXml(XmlWriter writer)
        {
 
        }

        public void ReadXml(XmlReader reader)
        {
            id = reader.GetAttribute("id");       
            XmlSerializer serializer = null;
            XmlReader xmlChildReader = null; 
            switch (id)
            {
                case "UserInfo":
                    serializer = new XmlSerializer(typeof(UserInfoRow)) ;
                    xmlChildReader = reader.ReadSubtree();
                    while (xmlChildReader.ReadToFollowing("row"))
                    {     
                        UserInfoRow userRow = (UserInfoRow)serializer.Deserialize(xmlChildReader);
                        if (userInfoRows == null) userInfoRows = new List<UserInfoRow>();
                        userInfoRows.Add(userRow);
                    }
                    break;
                case "UserTransactions":
                    serializer = new XmlSerializer(typeof(UserTransactionRow));
                    xmlChildReader = reader.ReadSubtree();
                    while (xmlChildReader.ReadToFollowing("row"))
                    {
                        UserTransactionRow userRow = (UserTransactionRow)serializer.Deserialize(xmlChildReader);
                        if (userTransactionRows == null) userTransactionRows = new List<UserTransactionRow>();
                        userTransactionRows.Add(userRow);
                    }
                    break;
            }
            reader.ReadEndElement();

        }

        public XmlSchema GetSchema()
        {
            return (null);
        }

    }
    [XmlRoot("row")]
    public class UserInfoRow
    {
        [XmlAttribute("id")]
        public string id { get; set; }
        [XmlAttribute("Name")]
        public string Name { get; set; }
        [XmlAttribute("phone")]
        public string phone { get; set; }
    }
    [XmlRoot("row")]
    public class UserTransactionRow
    {
        [XmlAttribute("UserId")]
        public string UserId { get; set; }
        [XmlAttribute("amount")]
        public string amount { get; set; }
        [XmlAttribute("date")]
        public string date { get; set; }
    }
}

Here is another solution that is more compact. I eliminated the documentData class

using System;
using System.Linq;
using System.Text;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Xml;
using System.Xml.Serialization;
using System.Xml.Schema;

namespace ConsoleApp2
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XmlReaderSettings settings = new XmlReaderSettings();
            settings.IgnoreWhitespace = true;
            XmlReader reader = XmlReader.Create(FILENAME);
            XmlSerializer serializer = new XmlSerializer(typeof(test.document));
            test.document doc = (test.document)serializer.Deserialize(reader);
 

        }

    }
 
}
namespace test
{
    public class document : IXmlSerializable
    {        
 
        public string id { get; set; }

        public List<UserInfoRow> userInfoRows { get; set; }
        public List<UserTransactionRow> userTransactionRows { get; set; }

        public void WriteXml(XmlWriter writer)
        {
 
        }

        public void ReadXml(XmlReader reader)
        {
            XmlSerializer serializer = null;
            XmlReader xmlChildReader = null;

            while (reader.ReadToFollowing("data"))
            {

                id = reader.GetAttribute("id");
                switch (id)
                {
                    case "UserInfo":
                        serializer = new XmlSerializer(typeof(UserInfoRow));
                        xmlChildReader = reader.ReadSubtree();
                        while (xmlChildReader.ReadToFollowing("row"))
                        {
                            UserInfoRow userRow = (UserInfoRow)serializer.Deserialize(xmlChildReader);
                            if (userInfoRows == null) userInfoRows = new List<UserInfoRow>();
                            userInfoRows.Add(userRow);
                        }
                        break;
                    case "UserTransactions":
                        serializer = new XmlSerializer(typeof(UserTransactionRow));
                        xmlChildReader = reader.ReadSubtree();
                        while (xmlChildReader.ReadToFollowing("row"))
                        {
                            UserTransactionRow userRow = (UserTransactionRow)serializer.Deserialize(xmlChildReader);
                            if (userTransactionRows == null) userTransactionRows = new List<UserTransactionRow>();
                            userTransactionRows.Add(userRow);
                        }
                        break;
                }
            }

        }

        public XmlSchema GetSchema()
        {
            return (null);
        }

    }
    [XmlRoot("row")]
    public class UserInfoRow
    {
        [XmlAttribute("id")]
        public string id { get; set; }
        [XmlAttribute("Name")]
        public string Name { get; set; }
        [XmlAttribute("phone")]
        public string phone { get; set; }
    }
    [XmlRoot("row")]
    public class UserTransactionRow
    {
        [XmlAttribute("UserId")]
        public string UserId { get; set; }
        [XmlAttribute("amount")]
        public string amount { get; set; }
        [XmlAttribute("date")]
        public string date { get; set; }
    }
}

Answer 2

The problem is that XmlInclude expects an xsi:type attribute, which you don't have.

You can include it manually, by first deserializing into an `XDocument, modifying that, then deserializing your objects from that

 XmlSerializer _serializer = new XmlSerializer(typeof(document));  // always cache

 public static void Main()
 {
     var xml = @"<?xml version=""1.0"" encoding=""UTF-8""?>
<document>
<data id=""UserInfo"">
 <rows>
   <row id=""123"" Name=""Alex"" phone=""+1234567890""></row>
   <row id=""321"" Name=""Sally"" phone=""+1234567890""></row>
 </rows>
</data>
<data id=""UserTransactions"">
 <rows>
   <row UserId=""123"" amount=""100.1"" date=""2022-07-03""></row>
   <row UserId=""123"" amount=""-100.1"" date=""2022-07-03""></row>
   <row UserId=""321"" amount=""1"" date=""2022-07-03""></row>
 </rows>
</data>
</document>
";
     var xdoc = XDocument.Parse(xml);
     AddTypeDefinition(xdoc);
     Console.WriteLine(xdoc.ToString());
     var obj = (document)_serializer.Deserialize(xdoc.CreateReader());
     Console.WriteLine(obj.data[0].rows[0].GetType().Name);
 }

 private static void AddTypeDefinition(XDocument document)
 {
     // XNamespace always converts from string implicitly
     XNamespace xsi = "http://www.w3.org/2001/XMLSchema-instance";
     document.Root.Add(new XAttribute(XNamespace.Xmlns + "xsi", xsi));
     foreach(var node in document.Root.Elements("data"))
     {
         string typeName;
         // decide based on "id" attribute
         if(node.Attribute("id").Value == "UserInfo")
             typeName = "UserInfoRow";
         else if(node.Attribute("id").Value == "UserInfo")
             typeName = "UserTransactionRow";
         else
             continue;

         foreach (var row in node.Element("rows").Elements("row"))
         {
             // xsi + "type" creates an XName with the namespace name
             // we have already added that declaration so becomes "xsi:type"
             row.Add(new XAttribute(xsi + "type", typeName));
         }
     }
 }

dotnetfiddle