Question

I’m trying to deserialize the following XML (excerpt):

<NSArray> 
  <Song id="23507" type="Song"> 
    <title>Waking The Demon</title> 
    <artist id="17" type="Artist"> 
      <nameWithoutThePrefix>Bullet For My Valentine</nameWithoutThePrefix> 
      <useThePrefix>false</useThePrefix> 
      <name>Bullet For My Valentine</name> 
    </artist> 
  </Song> 
  <Song id="3663" type="Song"> 
    <title>Hand Of Blood</title> 
    <artist id="17" type="Artist"/> 
  </Song> 
  <Song id="59226" type="Song"> 
    <title>Your Betrayal</title> 
    <artist id="17" type="Artist"/> 
  </Song> 
</NSArray> 

with the following classes:

[GeneratedCode("xsd", "4.0.30319.1")]
[DebuggerStepThrough]
[XmlType(AnonymousType = true)]
[XmlRoot(ElementName = "NSArray", Namespace = "", IsNullable = false)]
public class SearchResult
{
    [XmlElement("Song", Form = XmlSchemaForm.Unqualified)]
    public Song[] Items { get; set; }
}

[GeneratedCode("xsd", "4.0.30319.1")]
[DebuggerStepThrough]
[XmlType(AnonymousType = true)]
[XmlRoot(Namespace = "", IsNullable = false)]
public class Song
{
    [XmlElement(Form = XmlSchemaForm.Unqualified)]
    public string Title { get; set; }

    [XmlElement("artist", Form = XmlSchemaForm.Unqualified)]
    public Artist Artist { get; set; }

    [XmlAttribute]
    public string Type { get; set; }

    [XmlAttribute]
    public string Id { get; set; }
}

[GeneratedCode("xsd", "4.0.30319.1")]
[DebuggerStepThrough]
[XmlType(AnonymousType = true)]
public class Artist
{
    [XmlElement(Form = XmlSchemaForm.Unqualified)]
    public string NameWithoutThePrefix { get; set; }

    [XmlElement(Form = XmlSchemaForm.Unqualified)]
    public string UseThePrefix { get; set; }

    [XmlElement(Form = XmlSchemaForm.Unqualified)]
    public string Name { get; set; }

    [XmlAttribute]
    public string Type { get; set; }

    [XmlAttribute]
    public string Id { get; set; }
}

and the following code:

    var request = WebRequest.Create(string.Format("http://myurl.com");
    request.BeginGetResponse(GetEventResponseCallback, request);

    private void GetEventResponseCallback(IAsyncResult result)
    {
        var request = (HttpWebRequest)result.AsyncState;
        var response = request.EndGetResponse(result);

        if (response.GetResponseStream() == null) return;
        using (var stream = response.GetResponseStream())
        {
            _xmlReader = XmlReader.Create(stream);
            var songs = _xmlSerializer.Deserialize(_xmlReader) as SearchResult;
        }
    }

However, on var songs = _xmlSerializer.Deserialize(_xmlReader) as SearchResult;, the Deserialization executes successfully, but the songs variable does not contain any data. If I inspect with the debugger, it returns Could not evaluate expression for all the values in the array.

Any hints? Thanks.

Answer 1

Your SearchResult class needs some fixing. You’re really close, the code is only missing a few element names and the serializable attributes.

Here’s a class that works:

[GeneratedCode("xsd", "4.0.30319.1")]
[DebuggerStepThrough]
[XmlType(AnonymousType = true)]
[XmlRoot(ElementName = "NSArray", Namespace = "", IsNullable = false)]
[Serializable]
public class SearchResult
{
    [XmlElement("Song", Form = XmlSchemaForm.Unqualified)]
    public Song[] Items { get; set; }
}

[GeneratedCode("xsd", "4.0.30319.1")]
[DebuggerStepThrough]
[XmlType(AnonymousType = true)]
[XmlRoot(ElementName="Song", Namespace = "", IsNullable = false)]
[Serializable]
public class Song
{
    [XmlElement("title", Form = XmlSchemaForm.Unqualified)]
    public string Title { get; set; }

    [XmlElement("artist", Form = XmlSchemaForm.Unqualified)]
    public Artist Artist { get; set; }

    [XmlAttribute("type")]
    public string Type { get; set; }

    [XmlAttribute("id")]
    public string Id { get; set; }
}

[GeneratedCode("xsd", "4.0.30319.1")]
[DebuggerStepThrough]
[XmlType(AnonymousType = true)]
[Serializable]
public class Artist
{
    [XmlElement("nameWithoutThePrefix", Form = XmlSchemaForm.Unqualified)]
    public string NameWithoutThePrefix { get; set; }

    [XmlElement("useThePrefix", Form = XmlSchemaForm.Unqualified)]
    public string UseThePrefix { get; set; }

    [XmlElement("name", Form = XmlSchemaForm.Unqualified)]
    public string Name { get; set; }

    [XmlAttribute("type")]
    public string Type { get; set; }

    [XmlAttribute("id")]
    public string Id { get; set; }
}