MessageQuery.Evaluate 方法

參考

定義

命名空間:: System.ServiceModel.Dispatcher

組件:: System.ServiceModel.dll

重要

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在衍生類別中覆寫時，針對訊息執行查詢並且傳回符合查詢的值。

多載

Evaluate<TResult>(Message)	在衍生類別中覆寫時，針對訊息執行查詢並且傳回結果。本文無法進行查詢。
Evaluate<TResult>(MessageBuffer)	在衍生類別中覆寫時，針對訊息執行查詢並且傳回結果。

備註

這兩個多載之間的差異在於，其中一個會採用 Message 參數，但是不允許檢查本文；另一個則採用 MessageBuffer 參數，而且可以檢查訊息的任何部分。訊息標頭會自動進行緩衝，並且可以進行查詢，而不會被取用。不過，如果會查詢本文，則必須緩衝處理整個訊息，因為查詢可能取用未緩衝處理的訊息本文。

Evaluate<TResult>(Message)

在衍生類別中覆寫時，針對訊息執行查詢並且傳回結果。本文無法進行查詢。

public:
generic <typename TResult>
 abstract TResult Evaluate(System::ServiceModel::Channels::Message ^ message);

public abstract TResult Evaluate<TResult> (System.ServiceModel.Channels.Message message);

abstract member Evaluate : System.ServiceModel.Channels.Message -> 'Result

Public MustOverride Function Evaluate(Of TResult) (message As Message) As TResult

類型參數

TResult

要傳回的值型別。

參數

message: Message

要查詢的訊息。

傳回

TResult

MessageQueryCollection

符合查詢的可列舉結果集合。

適用於

Evaluate<TResult>(MessageBuffer)

在衍生類別中覆寫時，針對訊息執行查詢並且傳回結果。

public:
generic <typename TResult>
 abstract TResult Evaluate(System::ServiceModel::Channels::MessageBuffer ^ buffer);

public abstract TResult Evaluate<TResult> (System.ServiceModel.Channels.MessageBuffer buffer);

abstract member Evaluate : System.ServiceModel.Channels.MessageBuffer -> 'Result

Public MustOverride Function Evaluate(Of TResult) (buffer As MessageBuffer) As TResult

類型參數

TResult

要傳回的物件型別。

參數

buffer: MessageBuffer

要查詢的訊息。

傳回

TResult

MessageQueryCollection

符合查詢的可列舉結果集合。

範例

下列範例會建立訊息和 XPath 訊息查詢。查詢會由包含在 XPathMessageQuery 物件內的 XPathMessageQueryCollection 物件評估。每一個查詢的結果都會使用 ResultType 類別的 XPathResult 屬性測試。

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;
        }
    }
}

Imports System.IO
Imports System.Xml
Imports System.ServiceModel.Dispatcher
Imports System.ServiceModel
Imports System.ServiceModel.Channels
Imports System.Xml.XPath

Namespace MessageQueryExamples


    Public Class Program

        Public Shared Sub Main(ByVal args As String())

            ' The XPathMessageQueryCollection inherits from MessageQueryCollection.
            Dim queryCollection As XPathMessageQueryCollection = MessageHelper.SetupQueryCollection()


            ' Create a message and a copy of the message. You must create a buffered copy to access the message body.
            Dim mess As Message = MessageHelper.CreateMessage()
            Dim mb As MessageBuffer = mess.CreateBufferedCopy(Integer.MaxValue)


            ' Evaluate every query in the collection. 
            Dim q As XPathMessageQuery
            For Each q In queryCollection

                ' Evaluate the query. Note the result type is an XPathResult.
                Dim qPathResult As XPathResult = q.Evaluate(Of 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 Then
                    Console.WriteLine("{0} = {1}", q.Expression, qPathResult.GetResultAsString())
                End If
                If (qPathResult.ResultType = XPathResultType.NodeSet) Then

                    ' Iterate through the node set.
                    Dim ns As XPathNodeIterator = qPathResult.GetResultAsNodeset()
                    Dim n As XPathNavigator
                    For Each n In ns
                        Console.WriteLine("     {0} = {1}", q.Expression, n.Value)
                    Next
                End If
                If qPathResult.ResultType = XPathResultType.Number Then
                    Console.WriteLine("    {0} = {1}", q.Expression, qPathResult.GetResultAsNumber())
                End If
                If qPathResult.ResultType = XPathResultType.Boolean Then
                    Console.WriteLine("    {0} ={1}", q.Expression, qPathResult.GetResultAsBoolean())
                End If

                If qPathResult.ResultType = XPathResultType.Error Then
                    Console.WriteLine("    Error!")
                End If

            Next

            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.           

            'Dim mq As MessageQueryTable(Of String) = MessageHelper.SetupTable()
            'Dim kv As KeyValuePair(Of MessageQuery, String)
            'For Each kv In mq
            '    '
            '    Dim xp As XPathMessageQuery = CType(kv.Key, XPathMessageQuery)
            '    Console.WriteLine("Value = {0}", kv.Value)
            '    Console.WriteLine("{0} = {1}", xp.Expression, xp.Evaluate(Of String)(mb))
            'Next

            Console.ReadLine()
        End Sub
        Private Shared Sub Evaluate(ByVal p1 As Object)
            Throw New NotImplementedException
        End Sub
    End Class

    Public Class MessageHelper

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

        ' Invoke the correlation data function.


        Public Shared xpath9 As String = "sm:correlation-data('CorrelationData1')"
        Public Shared xpath10 As String = "sm:correlation-data('CorrelationData2')"

        Public Shared xpath11 As String = "/s12:Envelope/s12:Body/PurchaseOrder/Items/Item[@quantity = 2]"


        Public Shared Function CreateMessage() As Message

            Dim stringReader As New StringReader(messageBody)
            Dim xmlReader As New XmlTextReader(stringReader)
            Dim message As 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.
            Dim data As New CorrelationDataMessageProperty()

            data.Add("CorrelationData1", Function() "value1")
            data.Add("CorrelationData2", Function() "value2")
            message.Properties(CorrelationDataMessageProperty.Name) = data


            Return message
        End Function


        Public Shared Function SetupQueryCollection() As XPathMessageQueryCollection

            ' Create the query collection and add the XPath queries to it. To create
            ' the query, you must also use a new XPathMessageContext.

            Dim queryCollection As New XPathMessageQueryCollection()

            Dim context As XPathMessageContext = 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
        End Function

        Public Shared Function SetupTable() As MessageQueryTable(Of String)

            ' This is optional code to demonstrate using a MessageQueryTable.
            ' Compare this to the MessageQueryCollection.
            Dim table As MessageQueryTable(Of String) = New MessageQueryTable(Of String)()
            Dim context As XPathMessageContext = 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
        End Function
    End Class
End Namespace

適用於

共用方式為

MessageQuery.Evaluate 方法

定義

多載

備註

Evaluate<TResult>(Message)

類型參數

參數

傳回

適用於

Evaluate<TResult>(MessageBuffer)

類型參數

參數

傳回

範例

適用於

其他資源