serializing key value pairs in a dictionary with System.Xml.Serialization.XmlSerializer

XmlKeyValues.cs

[TestFixture]
public class TrackXml {
    [Test]
    public void ShouldSerialiseKeyValuePairs() {
        var xml = @"<track><title>Abracadabra</title><artist>Steve Miller Band</artist></track>";

        var track = new Track();
        track.Properties["title"] = "Abracadabra";
        track.Properties["artist"] = "Steve Miller Band";

        track.AssertSerializesAs(xml);
    }

    [Test]
    public void ShouldDeserialiseKeyValuePairs() {
        var xml = @"<track><title>Abracadabra</title><artist>Steve Miller Band</artist></track>";

        var xser = new XmlSerializer(typeof (Track));
        var actualTrack = (Track) xser.Deserialize(new StringReader(xml));

        Assert.That(actualTrack.Properties["title"], Is.EqualTo("Abracadabra"));
        Assert.That(actualTrack.Properties["artist"], Is.EqualTo("Steve Miller Band"));
        Assert.That(actualTrack.Properties.Count, Is.EqualTo(2));
    }
}

[XmlRoot("track")]
public class Track {
    [XmlIgnore]
    public Dictionary<string, string> Properties = new Dictionary<string, string>();

    [XmlAnyElement]
    public XElement[] XmlProperties {
        get {
            return Properties.Select(entry => new XElement(entry.Key, entry.Value)).ToArray();
        }
        set {
            Properties = value.ToDictionary(el => el.Name.LocalName, el => el.Value);
        }
    }
}