C＃中的复杂Xml名称空间

Question

I am trying to create an xml with multiple namespaces in c#. I am using LINQ XDocument object to create xml. The multiple namespaces of xml are causing a lot of confusion. Can anyone help me out on right direction please.

<?xml version="1.0" encoding="UTF-8"?>
<n1:Form109495CTransmittalUpstream
xmlns="urn:us:gov:treasury:irs:ext:aca:air:6.2" xmlns:irs="urn:us:gov:treasury:irs:common"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:n1="urn:us:gov:treasury:irs:msg:form1094-1095Ctransmitterupstreammessage"
xsi:schemaLocation="urn:us:gov:treasury:irs:msg:form1094-1095Ctransmitterupstreammessage IRS-Form1094-1095CTransmitterUpstreamMessage.xsd">
<Form1094CUpstreamDetail recordType="String" lineNum="0">
    <SubmissionId>1</SubmissionId>
    <irs:TaxYr>1000</irs:TaxYr>
    <irs:CorrectedInd>true</irs:CorrectedInd>
 </Form1094CUpstreamDetail>
</n1:Form109495CTransmittalUpstream>

C# Code

            new XDocument(
            new XAttribute(XNamespace.Xmlns + "version", "1.0"),
            new XAttribute(XNamespace.Xmlns + "encoding", "UTF-8"),
                new XElement("n1:Form109495CTransmittalUpstream","")
            ).Save("sample.xml");

Answer 1

As you may be aware, a 'qualified name' in XML is made up of the namespace and the local name. To make this easier to deal with, you include namespace declarations that prefix these namespaces.

So, for example, where you see irs:TaxYr , the qualified name is actually made up of the urn:us:gov:treasury:irs:common namespace and the TaxYr local name.

The prefix values themselves are pretty unimportant - they're just a lookup mechanism. LINQ to XML will handle this for you automatically (by generating unique prefixes, usually p1 , p2 etc.), but you can include them as attributes yourself. To create such a declaration for the irs namespace you'd create the following attribute:

new XAttribute(XNamespace.Xmlns + "irs", "urn:us:gov:treasury:irs:common")

LINQ to XML also provides some nifty implicit conversions, allowing you to create an XNamespace and qualified XName implicitly from a string. So, to get your TaxYr name you'd do the following:

XNamespace irs = "urn:us:gov:treasury:irs:common";
XName taxYr = irs + "TaxYr";

Following this all the way through for each of your elements and attributes, your XML could be created declaratively like so:

XNamespace def = "urn:us:gov:treasury:irs:ext:aca:air:6.2";
XNamespace irs = "urn:us:gov:treasury:irs:common";
XNamespace n1 = "urn:us:gov:treasury:irs:msg:form1094-1095Ctransmitterupstreammessage";
XNamespace xsi = "http://www.w3.org/2001/XMLSchema-instance";
var schemaHint = "urn:us:gov:treasury:irs:msg:form1094-1095Ctransmitterupstreammessage IRS-Form1094-1095CTransmitterUpstreamMessage.xsd";

var doc = new XDocument(
    new XElement(n1 + "Form109495CTransmittalUpstream",
        new XAttribute("xmlns", def),
        new XAttribute(XNamespace.Xmlns + "irs", irs),
        new XAttribute(XNamespace.Xmlns + "xsi", xsi),
        new XAttribute(XNamespace.Xmlns + "n1", n1),
        new XAttribute(xsi + "schemaLocation", schemaHint),
        new XElement(def + "Form1094CUpstreamDetail",
            new XAttribute("recordType", "String"),
            new XAttribute("lineNum", 0),
            new XElement(def + "SubmissionId", 1),
            new XElement(irs + "TaxYr", 1000),
            new XElement(irs + "CorrectedInd", true)
            )
        )
    );

Answer 2

This is how I normally do it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Data;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string xml =
              "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
                "<n1:Form109495CTransmittalUpstream" +
                    " xmlns=\"urn:us:gov:treasury:irs:ext:aca:air:6.2\" xmlns:irs=\"urn:us:gov:treasury:irs:common\"" +
                    " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"" +
                    " xmlns:n1=\"urn:us:gov:treasury:irs:msg:form1094-1095Ctransmitterupstreammessage\"" +
                    " xsi:schemaLocation=\"urn:us:gov:treasury:irs:msg:form1094-1095Ctransmitterupstreammessage IRS-Form1094-1095CTransmitterUpstreamMessage.xsd\">" +
                "</n1:Form109495CTransmittalUpstream>";

            XDocument doc = XDocument.Parse(xml);
            XElement form109495CTransmittalUpstream = (XElement)doc.FirstNode;
            XNamespace  def = form109495CTransmittalUpstream.GetDefaultNamespace();
            XNamespace irs = form109495CTransmittalUpstream.GetNamespaceOfPrefix("irs");
            XNamespace n1 = form109495CTransmittalUpstream.GetNamespaceOfPrefix("n1");

            XElement form1094CUpstreamDetail = new XElement(def + "Form1094CUpstreamDetail", new XAttribute[] {
                new XAttribute("recordType", "String"), new XAttribute("lineNum", 0)
            });
            form109495CTransmittalUpstream.Add(form1094CUpstreamDetail);

            form109495CTransmittalUpstream.Add(new XElement("SubmissionId", 1));
            form109495CTransmittalUpstream.Add(new XElement(irs + "TaxYr", 1000));
            form109495CTransmittalUpstream.Add(new XElement(irs + "CorrectedInd", true));

        }
    }
}
​