XPath.Evaluate Method (XPathItem, long, long)XPath.Evaluate Method (XPathItem, Long, Long)XPath::Evaluate Method (XPathItem^, long, long)

Returns an IEnumerable<T>IEnumerable(Of T)IEnumerable<T> representing the result of evaluating the XPath expression.

Namespace: XmlPrime XmlPrime XmlPrime
Assembly: XmlPrime (in XmlPrime.dll)

Syntax

Public Function Evaluate( _
    contextItem As System.Xml.XPath.XPathItem, _
    contextPosition As Long, _
    contextSize As Long _
) As IEnumerable(Of System.Xml.XPath.XPathItem)

public IEnumerable<System.Xml.XPath.XPathItem> Evaluate(
    System.Xml.XPath.XPathItem contextItem,
    long contextPosition,
    long contextSize
)

public:
IEnumerable<System.Xml.XPath::XPathItem^>^ Evaluate(
    System.Xml.XPath::XPathItem^ contextItem, 
    long contextPosition, 
    long contextSize
)

Parameters

contextItem

Type: System.Xml.XPath.XPathItemSystem.Xml.XPath.XPathItemSystem.Xml.XPath::XPathItem^

The initial context item for the expression.

contextPosition

Type: System.Int64 System.Int64 System::Int64

The initial context position for the expression.

contextSize

Type: System.Int64 System.Int64 System::Int64

The initial context size for the expression.

Return Value

Type: System.Collections.Generic.IEnumerable<T>System.Collections.Generic.IEnumerable(Of T)System.Collections.Generic::IEnumerable<T>^

An IEnumerable<T>IEnumerable(Of T)IEnumerable<T> representing the result of evaluating the XPath expression.

Exceptions

Exception	Condition
ArgumentNullException ArgumentNullException ArgumentNullException	contextItem is `null` a null reference (`Nothing` in Visual Basic) `nullptr`.
ArgumentOutOfRangeException ArgumentOutOfRangeException ArgumentOutOfRangeException	contextSize is outside of the range 1 to MaxValue MaxValue MaxValue, or contextPosition is outside of the range 1 to contextSize.
XdmException XdmException XdmException	An error occurred evaluating the expression.

Remarks

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).

The results of the expression 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>.