Trying to deserialize xml array into C# classes with subclasses

Question

I've got a simple example that I've boiled down from my real code. The problem is that I can create a C# class below as long as I'm able to explicitly assign the type in the class hierarchy. But, my array of Panels doesn't create a subclassed TwoColumnPanel. Instead, I only get one panel in the list of Panels.

[TestMethod]
    public void XmlRepoCreatesTestRepo()
    {
        object obj;
        using (XmlReader reader = XmlReader.Create(new StringReader(TestXml)))
        {
            reader.MoveToContent();
            switch (reader.Name)
            {
                case "TestRepo":
                    obj = new XmlSerializer(typeof(TestRepo)).Deserialize(reader);
                    break;
                default:
                    throw new NotSupportedException("Unexpected: " + reader.Name);
            }
        }
    }

    public string TestXml = @"<TestRepo>
                                <Name>Wandercoder Was Here</Name>
                                <Page>
                                    <Panel>
                                        <ColumnAttribute>1</ColumnAttribute>
                                    </Panel>
                                    <TwoColumnPanel>
                                        <ColumnAttribute>2</ColumnAttribute>
                                    </TwoColumnPanel>
                                    <Panels>
                                        <Panel>
                                            <ColumnAttribute>1</ColumnAttribute>
                                        </Panel>
                                        <TwoColumnPanel>
                                            <ColumnAttribute>2</ColumnAttribute>
                                        </TwoColumnPanel>
                                    </Panels>
                                </Page>
                            </TestRepo>";
}

[DataContract]
[Serializable]
public class TestRepo
{
    [DataMember]
    public string Name { get; set; }
    [DataMember]
    public Page Page { get; set; }
}
[DataContract]
[Serializable]
public class Page
{
    //This works.
    [DataMember]
    public Panel Panel { get; set; }
    //This works, too.
    [DataMember]
    public TwoColumnPanel TwoColumnPanel { get; set; }
    //For this one, however, I only get the one Panel when I deserialize.
    //Why doesn't it properly deserialize the TwoColumnPanel specified in the xml above.
    [DataMember]
    public List<Panel> Panels { get; set; }
}
[DataContract]
[Serializable]
public class Panel
{
    [DataMember]
    public int ColumnAttribute { get; set; }
}
[DataContract]
[Serializable]
[XmlRoot("Panel")]
public class TwoColumnPanel : Panel
{
    public TwoColumnPanel()
    {
        ColumnAttribute = 2;
    }
}

score 3 · Accepted Answer · answered Mar 07 '16 at 23:27

[DataContract]
[Serializable]
public class Page
{
    //This works.
    [DataMember]
    public Panel Panel { get; set; }
    //This works, too.
    [DataMember]
    public TwoColumnPanel TwoColumnPanel { get; set; }
    //For this one, however, I only get the one Panel when I deserialize.
    //Why doesn't it properly deserialize the TwoColumnPanel specified in the xml above.
    [DataMember]
    [XmlArray("Panels")]
    [XmlArrayItem("TwoColumnPanel", typeof(TwoColumnPanel))]
    [XmlArrayItem("Panel", typeof(Panel))]
    public List<Panel> Panels { get; set; }
}

score 2 · Answer 2 · answered Mar 07 '16 at 23:25

2

Try using the XmlArrayItem attribute:

[DataMember]
[XmlArrayItem("Panel", typeof(Panel))]
[XmlArrayItem("TwoColumnPanel", typeof(TwoColumnPanel))]
public List<Panel> Panels { get; set; }

answered Mar 07 '16 at 23:25

vesan

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Trying to deserialize xml array into C# classes with subclasses

2 Answers2