Deserialize XML with multiple elements into single C# object

Question

I need to deserialize an XML document that looks like this:

<Root>
  <Items>
    <Item>
      <ItemHeader Attr1="A" Attr2="B" Attr3="C" />
      <ItemDetails Attr4="D" Attr5="E" />
    </Item>
    ...
  </Items>
</Root>

Into a class that looks like this:

[Serializable, XmlRoot("Item")]
Public class MyItem
{
  [XmlAttribute("Attr1")]
  public string Attr1 { get; set; }
  [XmlAttribute("Attr5")]
  public string Attr5 { get; set; }
}

And I am using the following code to perform the deserialization:

XDocument doc;
XElement rootElem = doc.Element("Root");

foreach (XElement xe in rootElem.Descendants("Item"))
{
  MyItem item = new MyItem();
  XmlSerializer xmlSerializer = new XmlSerializer(typeof(MyItem));
  XmlReader xRdr = xe.CreateReader();
  item = (MyItem)xmlSerializer.Deserialize(xRdr);
}

However, none of the elements are copied into the object instance.

Is this doable? Do I need to deserialize each sub Element?

Thanks

steve16351 · Accepted Answer · 2014-11-07 16:43:04Z

1

I'm not sure there's a way to do that using the default XML serializer via attributes, without doing the whole class structure to match your XML - so ItemHeader and ItemDetails would need their own class.

You can implement the IXmlSerializable interface though, so you can completely customize - if you must keep the structure of MyItem as it is.

static void Main(string[] args)
{
    XmlSerializer myItemSerializer = new XmlSerializer(typeof(MyItem));

    var xmlDoc = XDocument.Parse(@"<Item>
                                <ItemHeader Attr1=""A"" Attr2=""B"" Attr3=""C"" />
                                <ItemDetails Attr4=""D"" Attr5=""E"" />
                            </Item>");

    using (var reader = xmlDoc.CreateReader())
    {
        MyItem myItem = (MyItem)myItemSerializer.Deserialize(reader);
    }


    Console.Read();
}

[Serializable, XmlRoot("Item")]
public class MyItem : IXmlSerializable
{
    [XmlAttribute("Attr1")]
    public string Attr1 { get; set; }
    [XmlAttribute("Attr5")]
    public string Attr5 { get; set; }

    public System.Xml.Schema.XmlSchema GetSchema()
    {
        return null;
    }

    public void ReadXml(System.Xml.XmlReader reader)
    {
        reader.ReadStartElement("Item");

        do
        {
            switch (reader.Name)
            {
                case "ItemHeader":
                    Attr1 = reader.GetAttribute("Attr1");
                    reader.Read();
                    break;
                case "ItemDetails":
                    Attr5 = reader.GetAttribute("Attr5");
                    reader.Read();
                    break;
                default:
                    throw new XmlException(String.Format("{0} was not expected", reader.Name));
            }
        } while (reader.Name != "Item");


        reader.ReadEndElement();
    }

    public void WriteXml(System.Xml.XmlWriter writer)
    {
        writer.WriteStartElement("ItemHeader");
        writer.WriteAttributeString("Attr1", Attr1);
        writer.WriteEndElement();
        writer.WriteStartElement("ItemDetails");
        writer.WriteAttributeString("Attr5", Attr5);
        writer.WriteEndElement();
    }
}

edited Nov 7, 2014 at 16:43

answered Nov 7, 2014 at 16:19

steve16351

5,8572 gold badges21 silver badges33 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Mike Fenske Over a year ago

An oddity here, I am seeing that Attr1 gets set correctly and is still there inside of Main but not Attr5. Debugging through, Attr5 is being read and set but doesn't retain its value outside of the MyItem class scope.

Mike Fenske Over a year ago

That above comment is not entirely true :) My real example is slightly more complex and it is that one that where attribute from the secondary element are not "sticking" though they are being read in.

steve16351 Over a year ago

Sorry, not something I've been able to reproduce with the original XML you posted or what I have above. Note GetAttribute won't fail if not found, it'll just return null - it's also case sensitive. If it's not that i'll need the XML you have.

Mike Fenske Over a year ago

Mystery solved. I had another Element nested inside of ItemDetails and apparently when the reader hit the closing of ItemDetails, the reader just saw it as ItemDetails and since there were no attributes attached to the close, those attributes were assigned null values.

steve16351 Over a year ago

Ah. I guess reader.ReadOuterXml() instead of reader.Read() might have been a better/safer choice to have avoided that.

|

andrei.ciprian · Accepted Answer · 2014-11-07 16:09:55Z

0

The issue is the xml data you are receiving does not match the serialization attributes of MyItem, schemas differ. There are multiple ways around this but I guess the quickest and dirtiest solution would be to extract the part that interests you:

  XDocument doc = XDocument.Load (@"Your.xml"); 
  XElement rootElem = doc.Element("Root");
  XElement itemsElem = rootElem.Element("Items");
  foreach (XElement xe in itemsElem.Elements("Item"))
  {
    MyItem item = new MyItem()
    {
      Attr1 = xe.Element("ItemHeader").Attribute("Attr1").Value,
      Attr5 = xe.Element("ItemDetails").Attribute("Attr5").Value
    }; 
  }

answered Nov 7, 2014 at 16:09

andrei.ciprian

3,0451 gold badge21 silver badges29 bronze badges

1 Comment

Mike Fenske Over a year ago

Thanks for the reply and though a possible solution I'm going with Steve's above as I can keep the internal knowledge of the class and attributes away from the processing code.

Collectives™ on Stack Overflow

Deserialize XML with multiple elements into single C# object

2 Answers 2

6 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related