XML deserialization to object

Question

So i've been trying to deserialize this xml file to some objects, its simple enough but it keeps returning null to the objects, the data that i need is stored inside the attributes of the element.

Here is the XML.

 <exchangerates xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" type="Valutakurser" author="Danmarks Nationalbank" refcur="DKK" refamt="1">
<dailyrates id="2020-10-20">
    <currency code="AUD" desc="Australske dollar" rate="442,98"/>
    <currency code="BGN" desc="Bulgarske lev" rate="380,53"/>
</dailyrates>

And this is the deserialisation code.

public static T DeserializeElement<T>(string filename)
    {
        try
        {
            T result;
            XmlSerializer serializer = new XmlSerializer(typeof(T), new 
            XmlRootAttribute("exchangerates"));
            
            using (TextReader tr = new StringReader(filename))
            {
                result = (T)serializer.Deserialize(tr);
            }

            return result;
        }
        catch { throw; }
    } 

And these are the objects

[XmlRoot(Namespace = "http://www.w3.org/2001/XMLSchema-instance",
ElementName = "exchangerates",
DataType = "Valutakurser")]
[Serializable]
public class Valutakurser
{
    
    [XmlArray("dailyrates")]
    public DateTime Id { get; set; }
    public Currency Currency { get; set; }
}

[Serializable]
public class Currency
{
    public string Code { get; set; }
    public string Desc { get; set; }
    public double Rate { get; set; }

    public Currency() { }
}

Currently I keep getting this error and everything returned null:

InvalidOperationException: For non-array types, you may use the following attributes: XmlAttribute, XmlText, XmlElement, or XmlAnyElement

Answer 1

Try following :

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

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XmlReader reader = XmlReader.Create(FILENAME);
            XmlSerializer serializer = new XmlSerializer(typeof(Valutakurser));
            Valutakurser valutakurser = (Valutakurser)serializer.Deserialize(reader);

        }
    }
    [XmlRoot(ElementName = "exchangerates")]
    public class Valutakurser
    {
        [XmlAttribute]
        public DateTime id { get; set; }
        [XmlElement("dailyrates")]
        public DailyRates DalyRates { get; set; }
    }
    public class DailyRates
    {
        [XmlElement("currency")]
        public List<Currency> Currency { get; set; }
    }

    public class Currency
    {
        [XmlAttribute]
        public string code { get; set; }
        [XmlAttribute]
        public string desc { get; set; }
        [XmlAttribute]
        public double rate { get; set; }

        public Currency() { }
    }

}