如何从xmldocument中选择特定级别的节点

Question

XmlDocument is looks as below, want to select the one node that is under <soap:Body>

so, any first node under path: soap:Envelope/soap:Body/ so, at below example, need to select "DynamicNode" element (But, It should not be through "DynamicNode" as it can be any name under soap:Envelope/soap:Body/

 <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    <soap:Header>
    </soap:Header>
    <soap:Body>
        <DynamicNode> ....</DynamicNode>
    </soap:Body>
</soap:Envelope>

Tried with, doc.DocumentElement.SelectSingleNode("soap:Envelope/soap:Body/") but it did not work and throw exception.

Note: can not use Linq.Xml

Answer 1

Because xml contains namespaces, you must use the XmlNamespaceManager.

XmlDocument doc = new XmlDocument();
doc.Load("test.xml");

XmlNamespaceManager manager = new XmlNamespaceManager(doc.NameTable);
manager.AddNamespace("soap", "http://schemas.xmlsoap.org/soap/envelope/");

XmlNode body = doc.SelectSingleNode("//soap:Body", manager);
XmlNode first = body.FirstChild; // DynamicNode

---

If xml has the xml:space="preserve" attribute, the above code can return a whitespace node.

I can offer the following:

XmlNode first = doc.SelectSingleNode("//soap:Body/*[text()]", manager);

This will return the first non-empty element.

Answer 2

XmlDocument doc = new XmlDocument();
doc.LoadXml(...);

XmlNode target;
XmlNode root = doc.FirstChild;
for (int i = 0; i < root.ChildNodes.Count; i++)
{
    if (root.ChildNodes[i].Name == "soap:Body")
    {
         target = root.ChildNodes[i].ChildNodes[0];
    }

}

Not elegant, but target will contain the first child node of "soap:Body"