XPathDocument Constructor (XmlReader)
Assembly: System.Xml (in System.Xml.dll)
An XmlReader object can be used to load a whole XML document or part of an XML document into an XPathDocument. To load part of an XML document into an XPathDocument, position the XmlReader object on the top XML node to load data from. When you create an XPathDocument by using the XPathDocument constructor, data is loaded from the current top node through all its siblings. Afterwards, the XmlReader is positioned on the outer scope of the top XML node. Alternatively, you can use the XmlReader.ReadSubtree method to load the XPathDocument into a particular element in the XML document.
The following are important notes to consider when you use the XPathDocument constructor.
If the XmlReader object is positioned on a leaf node that is not valid for the root level of a document—for example, a white space or attribute node—the XmlReader object continues to read until it is positioned on a node that can be used for the root. The XPathDocument begins loading at this point.