Is it possible to deserialize XML into List<T>?

Question

Given the following XML:

<?xml version="1.0"?>
<user_list>
   <user>
      <id>1</id>
      <name>Joe</name>
   </user>
   <user>
      <id>2</id>
      <name>John</name>
   </user>
</user_list>

And the following class:

public class User {
   [XmlElement("id")]
   public Int32 Id { get; set; }

   [XmlElement("name")]
   public String Name { get; set; }
}

Is it possible to use XmlSerializer to deserialize the xml into a List<User> ? If so, what type of additional attributes will I need to use, or what additional parameters do I need to use to construct the XmlSerializer instance?

EDIT: An array ( User[] ) would be acceptable, if a bit less preferable as well.

Answer 1

Not sure about List<T> but Arrays are certainly do-able. And a little bit of magic makes it really easy to get to a List again.

public class UserHolder {
   [XmlElement("list")]
   public User[] Users { get; set; }

   [XmlIgnore]
   public List<User> UserList { get { return new List<User>(Users); } }
}

Answer 2

Yes, it will serialize and deserialize a List<>. Just make sure you use the [XmlArray] attribute if in doubt.

[Serializable]
public class A
{
    [XmlArray]
    public List<string> strings;
}

This works with both Serialize() and Deserialize().

Answer 3

You can encapsulate the list trivially:

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

[XmlRoot("user_list")]
public class UserList
{
    public UserList() {Items = new List<User>();}
    [XmlElement("user")]
    public List<User> Items {get;set;}
}
public class User
{
    [XmlElement("id")]
    public Int32 Id { get; set; }

    [XmlElement("name")]
    public String Name { get; set; }
}

static class Program
{
    static void Main()
    {
        XmlSerializer ser= new XmlSerializer(typeof(UserList));
        UserList list = new UserList();
        list.Items.Add(new User { Id = 1, Name = "abc"});
        list.Items.Add(new User { Id = 2, Name = "def"});
        list.Items.Add(new User { Id = 3, Name = "ghi"});
        ser.Serialize(Console.Out, list);
    }
}

Answer 4

Yes, it does deserialize to List<>. No need to keep it in an array and wrap/encapsulate it in a list.

public class UserHolder
{
    private List<User> users = null;

    public UserHolder()
    {
    }

    [XmlElement("user")]
    public List<User> Users
    {
        get { return users; }
        set { users = value; }
    }
}

Deserializing code,

XmlSerializer xs = new XmlSerializer(typeof(UserHolder));
UserHolder uh = (UserHolder)xSerializer.Deserialize(new StringReader(str));