Setter not called when deserializing a collection

Question

I am trying to make a very simple bit of serialization using XmlSerializer:

public struct XmlPerson
{
    [XmlAttribute] public string Id   { get; set; }
    [XmlAttribute] public string Name { get; set; }
}

public class GroupOfPeople
{
    private Dictionary<string, string> _namesById = new Dictionary<string, string>();

    //pseudo property for serialising dictionary to/from XML
    public List<XmlPerson> _XmlPeople
    {
        get
        {
            var people = new List<XmlPerson>();
            foreach (KeyValuePair<string, string> pair in _namesById )
                people.Add(new XmlPerson() { Id = pair.Key, Name = pair.Value });

            return people;
        }
        set
        {
            _namesById.Clear();
            foreach (var person in value)
                _namesById.Add(person.Id, person.Name);
        }
    }     
} 

Saving this class works fine, and I get:

<?xml version="1.0" encoding="utf-8"?>
<GroupOfPeople xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <_XmlPeople>
        <XmlPerson Id="person1" Name="Fred" />
        <XmlPerson Id="person2" Name="Bill" />
        <XmlPerson Id="person3" Name="Andy" />
        <XmlPerson Id="person4" Name="Nagesh" />
    </_XmlPeople>
</GroupOfPeople>

However, when I read in the file again, my _XmlPeople property set is never called, and therefore the dictionary is empty. All other properties of this object are deserialized.

Am I missing something obvious? I tried various types of collections, but none of them deserialize.

EDIT : read code:

try
{
    using (var stream = new StreamReader(itemPath))
    {
        var xml = new XmlSerializer(typeof(GroupOfPeople));
        GroupOfPeople item = (GroupOfPeople)xml.Deserialize(stream);  
    }  
}
//snip error stuff

Answer 1

Have you tried using the XmlArray attribute?

In your example, it would be something like this:

[XmlArray]
[XmlArrayItem(ElementName="XmlPerson")]
public List<XmlPerson> XmlPeople

EDIT:

Here try the following structure:

public struct XmlPerson
{
    [XmlAttribute] public string Id   { get; set; }
    [XmlAttribute] public string Name { get; set; }
}


public class GroupOfPeople
{
    [XmlArray]
    [XmlArrayItem(ElementName="XmlPerson")]
    public List<XmlPerson> XmlPeople { get; set; }
}

, Setter , , ?

:

private Dictionary<string, string> _namesById;

public Dictionary<string, string> NamesById
{
    set { _namesById = value; }
    get
    {
        if (_namesById == null)
        {
            _namesById = new Dictionary<string, string>();

            foreach (var person in XmlPeople)
            {
                 _namesById.Add(person.Id, person.Name);
            }
        }

        return _namesById;
    }
}

XML, .

Answer 2

:

, XmlSerializer .

getter, . , , .

Answer 3

_XmlPeople "" _namesById, . .

, fooobar.com/questions/1110705/.... ( , "" , ).

, " " , , :

( " " _nameById, MyItem - XmlPerson)

public class MyProxyCollection : IList<MyItem> {
  MyProxyCollection(... /* reference to actual collection */ ...) {...}
  // Implement IList here
}

public class MyModel {
  MyProxyCollection _proxy;

  public MyModel() {
    _proxy = new MyProxyCollection (... /* reference to actual collection */ ...);
  }

  // Here we make sure the getter and setter always return a reference to the same
  // collection object. This ensures that we add items to the correct collection on
  // deserialization.
  public MyProxyCollection Items {get; set;}
}

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