Unable to deserialize XML to list using XML Deserializer

Question

This follows from my previous question Serialize the list of interfaces using XML serialization

    public class MeterWalkOrder
    {
        public MeterWalkOrder()
        {
            Meters = new List<IMeter>();
        }

        public String Name { get; set; }

        [XmlIgnore]
        public List<IMeter> Meters { get; set; }

        [XmlArrayItem(ElementName = "Meter")]
        [XmlArray(ElementName = "Meters")]
        public List<Meter> SerializableMeters
        {
            get
            {
                return Meters.Cast<Meter>().ToList();
            }
            set
            {
                Meters = new List<IMeter>(value);                
            }
        }
    }

     public interface IMeter {
       int MeterID { get; set; }
     }

     public class Meter : IMeter {
         public int MeterID { get; set; }
         public string SerialNumber { get; set; }
     }
}

I use the extension method below to deserialize the XML back to my object (ideally, I would prefer the extension method to be disconnected from the object, but I'm not too comfortable with extension methods, so I left it now) ...

public static class SerializationExtensions
{

    public static T LoadFromXML<T>(this string xmlString)
    {
        T returnValue = default(T);

        XmlSerializer serial = new XmlSerializer(typeof(T));
        StringReader reader = new StringReader(xmlString);
        object result = serial.Deserialize(reader);

        if (result != null && result is T)
        {
            returnValue = ((T)result);
        }

        reader.Close();

        return returnValue;
    }

.... However, when I give the XML below ....

<?xml version="1.0"?>
<MeterWalkOrder xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Name>Red Route</Name>
  <Meters>
    <Meter>
      <MeterID>1</MeterID>
      <SerialNumber>12345</SerialNumber>
    </Meter>
    <Meter>
      <MeterID>2</MeterID>
      <SerialNumber>SE</SerialNumber>
    </Meter>
  </Meters>
</MeterWalkOrder>

No counters are full?

Does anyone know what might cause this problem? XML is valid, and SerializeableMeters is just a property that reads and writes to Meters, but distinguishes it as a concrete class due to known problems using interfaces in serialization

Answer 1

, XmlSerializer , , IList<T> :

• getter . null, . .

• , .

• . .

, List<Meter> ObservableCollection<Meter> :

    [XmlArrayItem(ElementName = "Meter")]
    [XmlArray(ElementName = "Meters")]
    public ObservableCollection<Meter> SerializableMeters
    {
        get
        {
            Debug.WriteLine("Returning proxy SerializableMeters");
            var list = new ObservableCollection<Meter>(Meters.Cast<Meter>());
            list.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(list_CollectionChanged);
            return list;
        }
        set
        {
            Debug.WriteLine("Setting proxy SerializableMeters");
            Meters = new List<IMeter>(value.Cast<IMeter>());
        }
    }

    static void list_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        var collection = (IList<Meter>)sender;
        Debug.WriteLine("Proxy collection changed to include : ");
        foreach (var item in collection)
            Debug.WriteLine("   " + item.ToString());
    } 

, :

Returning proxy SerializableMeters
Returning proxy SerializableMeters
Returning proxy SerializableMeters
Returning proxy SerializableMeters
Proxy collection changed to include : 
   Meter: 1, 12345
Proxy collection changed to include : 
   Meter: 1, 12345
   Meter: 2, SE

, .

, . - -, XmlSerializer , - , !

    [XmlArrayItem(ElementName = "Meter")]
    [XmlArray(ElementName = "Meters")]
    public Meter [] SerializableMeters
    {
        get
        {
            return Meters.Cast<Meter>().ToArray();
        }
        set
        {
            Meters = new List<IMeter>(value.Cast<IMeter>());
        }
    }

    var meters = xml.LoadFromXML<MeterWalkOrder>();
    Debug.Assert(meters.Meters.Count == 2); // No assert.