c# - How to create XmlElement attributes with prefix?

Question

I need to be able to define an attribute with a prefix in a xml element.

For instance...

<nc:Person s:id="ID_Person_01"></nc:Person>

In order to do this I though that the following would have worked.

XmlElement TempElement = XmlDocToRef.CreateElement("nc:Person", "http://niem.gov/niem/niem-core/2.0");
TempElement.SetAttribute("s:id", "http://niem.gov/niem/structures/2.0", "ID_Person_01");

Unfortunately, XmlElement.SetAttribute(string, string, string) does not seem to support parsing the prefix as I receive the error below.

The ':' character, hexadecimal value 0x3A, cannot be included in a name.

How would I define an attribute with prefix?

Answer 1

If you've already declared your namespace in the root node, you just need to change the SetAttribute call to use the unprefixed attribute name. So if your root node defines a namespace like this:

<People xmlns:s='http://niem.gov/niem/structures/2.0'>

You can do this and the attribute will pick up the prefix you've already established:

// no prefix on the first argument - it will be rendered as
// s:id='ID_Person_01'
TempElement.SetAttribute("id", "http://niem.gov/niem/structures/2.0", "ID_Person_01");

If you have not yet declared the namespace (and its prefix), the three-string XmlDocument.CreateAttribute overload will do it for you:

// Adds the declaration to your root node
var attribute = xmlDocToRef.CreateAttribute("s", "id", "http://niem.gov/niem/structures/2.0");
attribute.InnerText = "ID_Person_01"
TempElement.SetAttributeNode(attribute);