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XPathResult Class

Contains the value returned by an XPath query.

System.Object
  System.ServiceModel.Dispatcher.XPathResult

Namespace:  System.ServiceModel.Dispatcher
Assembly:  System.ServiceModel (in System.ServiceModel.dll)

public sealed class XPathResult : IDisposable

The XPathResult type exposes the following members.

  NameDescription
Public propertyResultTypeReturns the type of the value returned by the XPath query.
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  NameDescription
Public methodDisposeReleases all resources owed by the object.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetResultAsBooleanReturns the result of the XPath query as a Boolean value.
Public methodGetResultAsNodesetReturns the result of the XPath query as an enumerable set of nodes.
Public methodGetResultAsNumberReturns the result of the XPath query as a number.
Public methodGetResultAsStringReturns the result of the XPath query as a string.
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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The following example creates a message and XPath message queries. The queries are evaluated by the XPathMessageQuery objects contained in an XPathMessageQueryCollection object. The results of each query are tested using the ResultType property of the XPathResult class.

using System;
using System.IO;
using System.Xml;
using System.ServiceModel.Dispatcher;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Xml.XPath;

namespace MessageQueryExamples
{

    class Program
    {
        static void Main(string[] args)
        {
            // The XPathMessageQueryCollection inherits from MessageQueryCollection.
            XPathMessageQueryCollection queryCollection = MessageHelper.SetupQueryCollection();


            // Create a message and a copy of the message. You must create a buffered copy to access the message body.
            Message mess = MessageHelper.CreateMessage();
            MessageBuffer mb = mess.CreateBufferedCopy(int.MaxValue);


            // Evaluate every query in the collection.  
            foreach (XPathMessageQuery q in queryCollection)
            {
                // Evaluate the query. Note the result type is an XPathResult.
                XPathResult qPathResult = q.Evaluate<XPathResult>(mb);

                // Use the XPathResult to determine the result type.
                Console.WriteLine("Result type: {0}", qPathResult.ResultType);

                // The following code prints the result according to the result type. 

                if (qPathResult.ResultType == XPathResultType.String)
                    Console.WriteLine("{0} = {1}", q.Expression, qPathResult.GetResultAsString());

                if (qPathResult.ResultType == XPathResultType.NodeSet)
                {
                    // Iterate through the node set.
                    XPathNodeIterator ns = qPathResult.GetResultAsNodeset();
                    foreach (XPathNavigator n in ns)
                        Console.WriteLine("\t{0} = {1}", q.Expression, n.Value);
                }
                if (qPathResult.ResultType == XPathResultType.Number)
                    Console.WriteLine("\t{0} = {1}", q.Expression, qPathResult.GetResultAsNumber());

                if (qPathResult.ResultType == XPathResultType.Boolean)
                    Console.WriteLine("\t{0} ={1}", q.Expression, qPathResult.GetResultAsBoolean());

                if (qPathResult.ResultType == XPathResultType.Error)
                    Console.WriteLine("\tError!");
            }

            Console.WriteLine();

            // The alternate code below demonstrates similar funcionality using a MessageQueryTable. 
            // The difference is the KeyValuePair that requires a key to index each value. 
            // The code uses the expression as the key, and an arbitrary value for the value.            

            //MessageQueryTable<string> mq = MessageHelper.SetupTable(); 
            //foreach (KeyValuePair<MessageQuery, string> kv in mq) 
            //{ 
            //    XPathMessageQuery xp = (XPathMessageQuery)kv.Key; 
            //    Console.WriteLine("Value = {0}", kv.Value);
            //    Console.WriteLine("{0} = {1}", xp.Expression, xp.Evaluate<string>(mb));
            //}

            Console.ReadLine();
        }
    }

    public class MessageHelper
    {
        static string messageBody =
              "<PurchaseOrder date='today'>" +
                  "<Number>ABC-2009-XYZ</Number>" +
                  "<Department>OnlineSales</Department>" +
                  "<Items>" +
                      "<Item product='nail' quantity='1'>item1</Item>" +
                      "<Item product='screw' quantity='2'>item2</Item>" +
                      "<Item product='brad' quantity='3'>" +
                          "<SpecialOffer/>" +
                          "Special item4" +
                      "</Item>" +
                      "<Item product='SpecialNails' quantity='9'>item5</Item>" +
                      "<Item product='SpecialBrads' quantity='11'>" +
                          "<SpecialOffer/>" +
                          "Special item6" +
                      "</Item>" +
                      "<Item product='hammer' quantity='1'>item7</Item>" +
                      "<Item product='wrench' quantity='2'>item8</Item>" +
                  "</Items>" +
                "<Comments>" +
                "Rush order" +
                "</Comments>" +
              "</PurchaseOrder>";

        public static string xpath = "/s12:Envelope/s12:Body/PurchaseOrder/Items/Item[@quantity = 1]";
        public static string xpath2 = "/s12:Envelope/s12:Body/PurchaseOrder/Items/Item[@product = 'nail']";
        public static string xpath3 = "/s12:Envelope/s12:Body/PurchaseOrder/Comments";
        public static string xpath4 = "count(/s12:Envelope/s12:Body/PurchaseOrder/Items/Item)";
        public static string xpath5 = "substring(string(/s12:Envelope/s12:Body/PurchaseOrder/Number),5,4)";
        public static string xpath6 = "/s12:Envelope/s12:Body/PurchaseOrder/Department='OnlineSales'";
        public static string xpath7 = "//PurchaseOrder/@date";
        public static string xpath8 = "//SpecialOffer/ancestor::Item[@product = 'brad']";

        // Invoke the correlation data function. 


        public static string xpath9 = "sm:correlation-data('CorrelationData1')";
        public static string xpath10 = "sm:correlation-data('CorrelationData2')";

        public static string xpath11 = "/s12:Envelope/s12:Body/PurchaseOrder/Items/Item[@quantity = 2]";


        public static Message CreateMessage()
        {
            StringReader stringReader = new StringReader(messageBody);
            XmlTextReader xmlReader = new XmlTextReader(stringReader);
            Message message = Message.CreateMessage(MessageVersion.Soap12WSAddressing10, "http://purchaseorder", xmlReader);

            // Add two correlation properties using lambda expressions. The property names are 
            // CorrelationData1 and CorrelationData2. The first goes to "value1" and the
            // second to "value2". You can use your own property names and values.
            CorrelationDataMessageProperty data = new CorrelationDataMessageProperty();

            data.Add("CorrelationData1", () => "value1");
            data.Add("CorrelationData2", () => "value2");
            message.Properties[CorrelationDataMessageProperty.Name] = data;

            return message;
        }



        public static XPathMessageQueryCollection SetupQueryCollection()
        {
            // Create the query collection and add the XPath queries to it. To create 
            // the query, you must also use a new XPathMessageContext.

            XPathMessageQueryCollection queryCollection = new XPathMessageQueryCollection();

            XPathMessageContext context = new XPathMessageContext();
            queryCollection.Add(new XPathMessageQuery(xpath, context));
            queryCollection.Add(new XPathMessageQuery(xpath2, context));
            queryCollection.Add(new XPathMessageQuery(xpath3, context));
            queryCollection.Add(new XPathMessageQuery(xpath4, context));
            queryCollection.Add(new XPathMessageQuery(xpath5, context));
            queryCollection.Add(new XPathMessageQuery(xpath6, context));
            queryCollection.Add(new XPathMessageQuery(xpath7, context));
            queryCollection.Add(new XPathMessageQuery(xpath8, context));
            queryCollection.Add(new XPathMessageQuery(xpath9, context));
            queryCollection.Add(new XPathMessageQuery(xpath10, context));
            queryCollection.Add(new XPathMessageQuery(xpath11, context));

            return queryCollection;
        }

        public static MessageQueryTable<string> SetupTable()
        {
            // This is optional code to demonstrate using a MessageQueryTable. 
            // Compare this to the MessageQueryCollection.
            MessageQueryTable<string> table = new MessageQueryTable<string>();
            XPathMessageContext context = new XPathMessageContext();


            // The code adds a KeyValuePair to the table. Each pair requires 
            // a query used as the Key, and a value that is paired to the key.
            table.Add(new XPathMessageQuery(xpath, context), "value10");
            table.Add(new XPathMessageQuery(xpath2, context), "value20");
            table.Add(new XPathMessageQuery(xpath3, context), "value30");
            table.Add(new XPathMessageQuery(xpath4, context), "value40");
            table.Add(new XPathMessageQuery(xpath5, context), "value50");
            table.Add(new XPathMessageQuery(xpath6, context), "value60");
            table.Add(new XPathMessageQuery(xpath7, context), "value70");
            table.Add(new XPathMessageQuery(xpath8, context), "value80");
            table.Add(new XPathMessageQuery(xpath9, context), "value90");
            table.Add(new XPathMessageQuery(xpath10, context), "value100");
            table.Add(new XPathMessageQuery(xpath11, context), "value110");
            return table;
        }
    }    
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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