Question

I’ve the problem:

I have to serialize class to XML file. But two properties must be named with the same name:

Desired xml:

<?xml version="1.0"?>
<Test>
  <HeaderText>
    <Tag1>AAA</Tag1>
  </HeaderText>
  <HeaderText>
    <Tag2>BBB</Tag2>
  </HeaderText>
</Test>

I don’t need to deserialize it back to object.

Code:

public class Header1
{
    [XmlElement("Tag1")]
    public String Tag1 { get; set; }
}

public class Header2
{
    [XmlElement("Tag2")]
    public String Tag2 { get; set; }
}

public class Test
{
    [XmlElement("HeaderText")]
    public Header1 Header1 { get; set; }

    [XmlElement("HeaderText")]
    public Header2 Header2 { get; set; }
}

var doc = new Test
{
    Header1 = new Header1 { Tag1 = "AAA" },
    Header2 = new Header2 { Tag2 = "BBB" }
};

var xml = new XmlSerializer(typeof(Test));
using (var fs = new FileStream("test.xml", FileMode.Create))
{
    xml.Serialize(fs, doc);
}

This code doesn’t work.

The XML element ‘HeaderText’ from namespace ” is already present in the current scope. Use XML attributes to specify another XML name or namespace for the element.

What can I do?

Real-world example:

  <Product>
    <RecordReference>1-15991</RecordReference>
    <MainSubject>
      <MainSubjectSchemeIdentifier>66</MainSubjectSchemeIdentifier>
      <SubjectCode>2</SubjectCode>
    </MainSubject>
    <MainSubject>
      <MainSubjectSchemeIdentifier>20</MainSubjectSchemeIdentifier>
      <SubjectHeadingText>Venäläisiä kirjoja: uskonto, teosofia, mystiikka</SubjectHeadingText>
    </MainSubject>
</Product>

Answer 1

Use an array:

public class Test
{
    [XmlElement("HeaderText")]
    public string[] HeaderText { get; set; }
}

and then:

var doc = new Test
{
    HeaderText = new[] { "AAA", "BBB" }
};
var xml = new XmlSerializer(typeof(Test));
using (var fs = new FileStream("test.xml", FileMode.Create))
{
    xml.Serialize(fs, doc);
}

Also works with List<string>.

---

UPDATE:

With complex objects you define a model:

public class Header
{
    public string Tag { get; set; }
}

and then you have a collection of this model:

public class Test
{
    [XmlElement("HeaderText")]
    public Header[] HeaderText { get; set; }
}

and then you serialize:

var doc = new Test
{
    HeaderText = new[] 
    { 
        new Header { Tag = "AAA" }, 
        new Header { Tag = "BBB" }
    }
};
var xml = new XmlSerializer(typeof(Test));
using (var fs = new FileStream("test.xml", FileMode.Create))
{
    xml.Serialize(fs, doc);
}