Deserialization Error: The XML element 'name' from namespace '' is already present in the current scope

Question

This is my first time using XML Serialization and this is driving me absolutely nuts after 2 days of trying to troubleshoot this.

I get this error w

Answer 1

Ok - I coded up an example. I took a look at the Facebook API, now here is a FULL working example. Try this:

[XmlRoot("photos_getAlbums_response", Namespace="http://api.facebook.com/1.0/")]
public class GetAlbumsResponse
{
    public GetAlbumsResponse() 
    {    
    }

    [XmlElement("album")]
    public List<Album> Albums { get; set; }
}

public class Album
{
    [XmlElement("aid")]
    public long Aid{get;set;}

    [XmlElement("cover_pid")]
    public long CoverPid{get;set;}

    [XmlElement("owner")]
    public long Owner{get;set;}

    [XmlElement("name")]
    public string Name{get;set;}

    [XmlElement("created")]
    public long Created{get;set;}

    [XmlElement("modified")]
    public long Modified{get;set;}

    [XmlElement("description")]
    public string Description{get;set;}

    [XmlElement("location")]
    public string Location{get;set;}

    [XmlElement("link")]
    public string Link{get;set;}

    [XmlElement("size")]
    public int Size{get;set;}

    [XmlElement("visible")]
    public string Visible{get;set;}

    public Album()
    {}
}

class XmlUtils
{
    public static T DeserializeFromXml<T>(string xml)
    {
        T result;
        XmlSerializer ser = new XmlSerializer(typeof(T));
        using (TextReader tr = new StringReader(xml))
        {
            result = (T)ser.Deserialize(tr);
        }
        return result;
    }
}

Now.. with an xml photos_getAlbums_response from the Facebook API,

You can deserialize like this:

 GetAlbumsResponse response = XmlUtils.DeserializeFromXml<GetAlbumsResponse>(xmlResponseString);

Answer 2

Use System.Xml.XmlDocument to parse the input. It shouldn't take more than an hour to write the code to extract the data yourself.

Answer 3

Personally, I wouldn't use constants here - they make it hard to spot errors (and since you probably aren't re-using them, don't add much). For example:

    [XmlElement (ElementName = ElementConstants.AlbumName, DataType = "string")]
    public string AlbumID { get; set; }
...
    [XmlElement(ElementName = ElementConstants.AlbumName, DataType = "string")]
    public string AlbumName { get; set; }

Looks suspect to me...

An easier approach is to write the xml you want to a file (foo.xml, say) and use:

xsd foo.xml
xsd foo.xsd /classes

Then look at foo.cs.

Answer 4

Here we go... note the xml was invalid (& should be &; use of undeclared xsi namespace-alias). Note also that I added an enum for the visibility, added handling for converting the long to DateTime, and added the wrapper type:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Xml;
using System.Xml.Serialization;

static class Program
{
    const string xml = @"<?xml version=""1.0"" encoding=""UTF-8""?>
<photos_GetAlbums_response
    xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance""
    xsi:schemaLocation=""http://api.example.com/1.0/ http://api.example.com/1.0/xxx.xsd""
    list=""true"">
<album>
 <aid>3231990241086938677</aid>
 <cover_pid>7031990241087042549</cover_pid>
 <owner>1337262814</owner>
 <name>LA</name>
 <created>1233469624</created>
 <modified>1233469942</modified>
 <description>trip to LA</description>
 <location>CA</location>
 <link>http://www.example.com/album.php?aid=7333&amp;id=1337262814</link>
 <size>48</size>
 <visible>friends</visible>
 </album>
<album>
 <aid>7031990241086936240</aid>
 <cover_pid>7031990241087005994</cover_pid>
 <owner>1337262814</owner>
 <name>Wall Photos</name>
 <created>1230437805</created>
 <modified>1233460690</modified>
 <description/>
 <location/>
 <link>http://www.example.com/album.php?aid=3296&amp;id=1337262814</link>
 <size>34</size>
 <visible>everyone</visible>
 </album>
<album>
 <aid>7031990241086937544</aid>
 <cover_pid>7031990241087026027</cover_pid>
 <owner>1337262814</owner>
 <name>Mobile Uploads</name>
 <created>1231984989</created>
 <modified>1233460349</modified>
 <description/>
 <location/>
 <link>http://www.example.com/album.php?aid=6300&amp;id=1337262814</link>
 <size>3</size>
 <visible>friends</visible>
 </album>
<album>
 <aid>7031990241086936188</aid>
 <cover_pid>7031990241087005114</cover_pid>
 <owner>1337262814</owner>
 <name>Christmas 2008</name>
 <created>1230361978</created>
 <modified>1230362306</modified>
 <description>My Album</description>
 <location/>
 <link>http://www.example.com/album.php?aid=5234&amp;id=1337262814</link>
 <size>50</size>
 <visible>friends</visible>
 </album>
<album>
 <aid>7031990241086935881</aid>
 <cover_pid>7031990241087001093</cover_pid>
 <owner>1637262814</owner>
 <name>Hock</name>
 <created>1229889219</created>
 <modified>1229889235</modified>
 <description>Misc Pics</description>
 <location/>
 <link>http://www.example.com/album.php?aid=4937&amp;id=1637262814</link>
 <size>1</size>
 <visible>friends-of-friends</visible>
 </album>
<album>
 <aid>7031990241086935541</aid>
 <cover_pid>7031990241086996817</cover_pid>
 <owner>1637262814</owner>
 <name>Test Album 2 (for work)</name>
 <created>1229460455</created>
 <modified>1229460475</modified>
 <description>this is a test album</description>
 <location/>
 <link>http://www.example.com/album.php?aid=4547&amp;id=1637262814</link>
 <size>1</size>
 <visible>everyone</visible>
 </album>
<album>
 <aid>7031990241086935537</aid>
 <cover_pid>7031990241086996795</cover_pid>
 <owner>1637262814</owner>
 <name>Test Album (for work)</name>
 <created>1229459168</created>
 <modified>1229459185</modified>
 <description>Testing for work</description>
 <location/>
 <link>http://www.example.com/album.php?aid=4493&amp;id=1637262814</link>
 <size>1</size>
 <visible>friends</visible>
 </album>
 </photos_GetAlbums_response>";
    static void Main()
    {
        XmlSerializer ser = new XmlSerializer(typeof(GetAlbumsResponse));
        GetAlbumsResponse response;
        using (StringReader reader = new StringReader(xml))
        {
            response = (GetAlbumsResponse)ser.Deserialize(reader);
        }

    }
}

[Serializable, XmlRoot("photos_GetAlbums_response")]
public class GetAlbumsResponse
{
    [XmlElement("album")]
    public List<Album> Albums {get;set;}

    [XmlAttribute("list")]
    public bool IsList { get; set; }
}
public enum AlbumVisibility
{
    [XmlEnum("")]
    None,
    [XmlEnum("friends")]
    Friends,
    [XmlEnum("friends-of-friends")]
    FriendsOfFriends,
    [XmlEnum("everyone")]
    Everyone

}
[Serializable]
public class Album
{
    static readonly DateTime epoch = new DateTime(1970, 1, 1);
    static long SerializeDateTime(DateTime value)
    {
        return (long)((value - epoch).TotalSeconds);
    }
    static DateTime DeserializeDateTime(long value)
    {
        return epoch.AddSeconds(value);
    }
    [XmlElement("aid")]
    public long AlbumID { get; set; }

    [XmlElement("cover_pid")]
    public long CoverPhotoID { get; set; }

    [XmlElement("owner")]
    public long Owner { get; set; }

    [XmlElement("name")]
    public string AlbumName { get; set; }

    [XmlIgnore]
    public DateTime CreateDate { get; set; }

    [XmlElement("created"), Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public long CreateDateInt64 {
        get {return SerializeDateTime(CreateDate);}
        set {CreateDate = DeserializeDateTime(value);}
    }

    [XmlIgnore]
    public DateTime LastModifiedDate { get; set; }

    [XmlElement("modified"), Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public long LastModifiedDateInt64
    {
        get { return SerializeDateTime(LastModifiedDate); }
        set { LastModifiedDate = DeserializeDateTime(value); }
    }

    [XmlElement("description")]
    public string Description { get; set; }

    [XmlElement("location")]
    public string Location { get; set; }

    [XmlElement("link")]
    public string Link { get; set; }

    [XmlElement("size")]
    public int Size { get; set; }

    [XmlElement("visible")]
    public AlbumVisibility Visibility { get; set; }
}

Answer 5

Well,

there is a link from Microsoft targeting your problem

Answer 6

The Xml that would work for your current code is something like this:

<Album><photos_GetAlbums_response>
<Album>
   <photos_GetAlbums_response>
      <Album>
         <photos_GetAlbums_response> ....

A response, which has an array of Albums, where each Album has a response which is an Array of Albums...etc.

Anyway, I already helped you in your other question, and even went to the trouble of creating a full working code sample. Why did you create another question for the same problem ?