XQuery.Evaluate Method (XPathItem)XQuery.Evaluate Method (XPathItem)XQuery::Evaluate Method (XPathItem^)

Returns an IEnumerable<T>IEnumerable(Of T)IEnumerable<T> representing the result of evaluating the XQuery program.

Syntax

Public Function Evaluate( _
    contextItem As System.Xml.XPath.XPathItem _
) As IEnumerable(Of System.Xml.XPath.XPathItem)

public IEnumerable<System.Xml.XPath.XPathItem> Evaluate(
    System.Xml.XPath.XPathItem contextItem
)

public:
IEnumerable<System.Xml.XPath::XPathItem^>^ Evaluate(
    System.Xml.XPath::XPathItem^ contextItem
)

contextItem

The initial context item for the query.

An IEnumerable<T>IEnumerable(Of T)IEnumerable<T> representing the result of evaluating the XQuery program.

Exception	Condition
ArgumentNullException ArgumentNullException ArgumentNullException	contextItem is `null` a null reference (`Nothing` in Visual Basic) `nullptr`.
InvalidOperationException InvalidOperationException InvalidOperationException	The query is an updating expression.
XdmException XdmException XdmException	An error occurred evaluating the query.

The results of the query are only evaluated whilst they are enumerated. Any errors encountered during evaluation may be thrown from the MoveNext MoveNext MoveNext method and Current Current Current property of the enumerator over the IEnumerable<T>IEnumerable(Of T)IEnumerable<T>.

The items in the returned IEnumerable<T>IEnumerable(Of T)IEnumerable<T> will all be instances of XPathNavigator XPathNavigator XPathNavigator (if the expression returns a node), XPathAtomicValue XPathAtomicValue XPathAtomicValue (if the expression returns an atomic value) or XPathFunctionItem XPathFunctionItem XPathFunctionItem (if the expression returns a function item).