IXPathEvaluator.Evaluate

IXPathEvaluator.Evaluate method

Evaluates an XPath expression String and returns a result of the specified type if possible.

public IXPathResult Evaluate(String expression, Node contextNode, IXPathNSResolver resolver, 
    XPathResultType type, object result)
ParameterTypeDescription
expressionStringThe XPath expression String to be parsed and evaluated.
contextNodeNodeThe context is context node for the evaluation of this XPath expression. If the IXPathEvaluator was obtained by casting the Document then this must be owned by the same document and must be a Document, Element, Attr, Text, CDATASection, Comment, ProcessingInstruction, or XPathNamespace node. If the context node is a Text or a CDATASection, then the context is interpreted as the whole logical text node as seen by XPath, unless the node is empty in which case it may not serve as the XPath context.
resolverIXPathNSResolverThe resolver permits translation of all prefixes, including the xml package prefix, within the XPath expression into appropriate package URIs. If this is specified as null, any package prefix within the expression will result in DOMException being thrown with the code NAMESPACE_ERR.
typeXPathResultTypeIf a specific type is specified, then the result will be returned as the corresponding type. For XPath 1.0 results, this must be one of the values of the XPathResultType enum.
resultObjectThe result specifies a specific result object which may be reused and returned by this method. If this is specified as null or the implementation does not reuse the specified result, a new result object will be constructed and returned. For XPath 1.0 results, this object will be of type IXPathResult.

Return Value

The result of the evaluation of the XPath expression. For XPath 1.0 results, this object will be of type IXPathResult.

Exceptions

exceptioncondition
dOMExceptionINVALID_EXPRESSION_ERR: Raised if the expression is not legal according to the rules of the IXPathEvaluator.
dOMExceptionTYPE_ERR: Raised if the result cannot be converted to return the specified type.
dOMExceptionNAMESPACE_ERR: Raised if the expression contains package prefixes which cannot be resolved by the specified IXPathNSResolver.
dOMExceptionWRONG_DOCUMENT_ERR: The Node is from a document that is not supported by this IXPathEvaluator.
dOMExceptionNOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath context node or the request type is not permitted by this IXPathEvaluator.

See Also