Can I have null attribute and other attribute at the same tag in XML created by XSD C# generated class?

Question

I have a bunch of C# classes, which are auto generated from an XSD. Then I generate XML files based on those C# classes. Nothing existing so far.

The proble

Answer 1

As expected there is no solution for that case out of the box, so I improvise a bit and achieved my goal in a post processing logic.

I am parsing the generated XML and if I am looking for a node with xsi:nil attribute, but without NV attribute - I add NV attribute with default value. Same for the nodes with NV attribute, but no xsi:nil.

Here is the code:

        XmlDocument doc = new XmlDocument();// instantiate XmlDocument and load XML from file
        doc.Load("somepath.xml");

        //Get the nodes with NV attribute(using XPath) and add xsi:nill to that nodes
        XmlNodeList nodes = doc.SelectNodes("//*[@NV]");

        foreach (XmlNode node in nodes)
        {
            XmlAttribute nilAttr = doc.CreateAttribute("nil", "http://www.w3.org/2001/XMLSchema-instance");
            nilAttr.Value = "true";
            node.Attributes.Append(nilAttr);
        }

        //Get the nodes with xsi:nill attribute(using XPath) and add NV with default value to that nodes
        XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);
        nsManager.AddNamespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
        XmlNodeList nilNodes = doc.SelectNodes("//*[@xsi:nil]", nsManager);

        foreach (XmlNode node in nilNodes)
        {
            XmlAttribute nvAttr = doc.CreateAttribute("NV");
            nvAttr.Value = "7701003";
            node.Attributes.Append(nvAttr);
        }

        doc.Save("somepath.xml");

The upper answer makes totally sense, but since these classes are auto-generated I will do it my way with the post processing, cause if the provider changes the XSD schema, my solution doesn't need any extra work. Thanks anyway.