OperationContextScope 类

public ref class OperationContextScope sealed : IDisposable

public sealed class OperationContextScope : IDisposable

type OperationContextScope = class
    interface IDisposable

Public NotInheritable Class OperationContextScope
Implements IDisposable

继承

Object

OperationContextScope

实现

IDisposable

下面的示例演示如何使用 OperationContextScope 在客户端应用程序中创建新的上下文以向传出消息添加自定义标头。

using System;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Threading;

public class Client : ISampleServiceCallback
{
  ManualResetEvent wait = null;

  Client()
  {
    this.wait = new ManualResetEvent(false);
  }

  public static void Main()
  {
    Client client = new Client();
    client.Run();
  }

  void Run()
  {
    // Picks up configuration from the config file.
    SampleServiceClient wcfClient = new SampleServiceClient(new InstanceContext(this));
    try
    {
      using (OperationContextScope scope = new OperationContextScope(wcfClient.InnerChannel))
      {
        MessageHeader header
          = MessageHeader.CreateHeader(
          "Service-Bound-CustomHeader",
          "http://Microsoft.WCF.Documentation",
          "Custom Happy Value."
          );
        OperationContext.Current.OutgoingMessageHeaders.Add(header);

        // Making calls.
        Console.WriteLine("Enter the greeting to send: ");
        string greeting = Console.ReadLine();

        //Console.ReadLine();
        header = MessageHeader.CreateHeader(
            "Service-Bound-OneWayHeader",
            "http://Microsoft.WCF.Documentation",
            "Different Happy Value."
          );
        OperationContext.Current.OutgoingMessageHeaders.Add(header);

        // One-way
        wcfClient.Push(greeting);
        this.wait.WaitOne();

        // Done with service.
        wcfClient.Close();
        Console.WriteLine("Done!");
        Console.ReadLine();
      }
    }
    catch (TimeoutException timeProblem)
    {
      Console.WriteLine("The service operation timed out. " + timeProblem.Message);
      Console.ReadLine();
      wcfClient.Abort();
    }
    catch (CommunicationException commProblem)
    {
      Console.WriteLine("There was a communication problem. " + commProblem.Message);
      Console.ReadLine();
      wcfClient.Abort();
    }
  }


  #region ISampleServiceCallback Members

  public void PushBack(string msg)
  {
    Console.WriteLine("Service said: " + msg);
    this.WriteHeaders(OperationContext.Current.IncomingMessageHeaders);
    this.wait.Set();
  }

  void WriteHeaders(MessageHeaders headers)
  {
    Console.ForegroundColor = ConsoleColor.Red;
    Console.WriteLine("IncomingHeader:");
    Console.ForegroundColor = ConsoleColor.Blue;
    foreach (MessageHeaderInfo h in headers)
    {
      if (!h.Actor.Equals(String.Empty))
        Console.WriteLine("\t" + h.Actor);
      Console.ForegroundColor = ConsoleColor.White;
      Console.WriteLine("\t" + h.Name);
      Console.ForegroundColor = ConsoleColor.Blue;
      Console.WriteLine("\t" + h.Namespace);
      Console.WriteLine("\t" + h.Relay);
      if (h.IsReferenceParameter)
      {
        Console.WriteLine("IsReferenceParameter header detected: " + h.ToString());
      }
    }
    Console.ResetColor();
  }
  #endregion
}

Imports System.ServiceModel
Imports System.ServiceModel.Channels
Imports System.Threading

Public Class Client
    Implements ISampleServiceCallback
  Private wait As ManualResetEvent = Nothing

  Private Sub New()
    Me.wait = New ManualResetEvent(False)
  End Sub

  Public Shared Sub Main()
    Dim client As New Client()
    client.Run()
  End Sub

  Private Sub Run()
    ' Picks up configuration from the config file.
    Dim wcfClient As New SampleServiceClient(New InstanceContext(Me))
    Try
      Using scope As New OperationContextScope(wcfClient.InnerChannel)
                Dim header As MessageHeader = MessageHeader.CreateHeader("Service-Bound-CustomHeader", _
                                    "http://Microsoft.WCF.Documentation", "Custom Happy Value.")
        OperationContext.Current.OutgoingMessageHeaders.Add(header)

        ' Making calls.
        Console.WriteLine("Enter the greeting to send: ")
        Dim greeting As String = Console.ReadLine()

        'Console.ReadLine();
                header = MessageHeader.CreateHeader("Service-Bound-OneWayHeader", _
                                                    "http://Microsoft.WCF.Documentation", "Different Happy Value.")
        OperationContext.Current.OutgoingMessageHeaders.Add(header)

        ' One-way
        wcfClient.Push(greeting)
        Me.wait.WaitOne()

        ' Done with service. 
        wcfClient.Close()
        Console.WriteLine("Done!")
        Console.ReadLine()
      End Using
    Catch timeProblem As TimeoutException
      Console.WriteLine("The service operation timed out. " & timeProblem.Message)
      Console.ReadLine()
      wcfClient.Abort()
    Catch commProblem As CommunicationException
      Console.WriteLine("There was a communication problem. " & commProblem.Message)
      Console.ReadLine()
      wcfClient.Abort()
    End Try
  End Sub


  #Region "ISampleServiceCallback Members"

  Public Sub PushBack(ByVal msg As String) Implements ISampleServiceCallback.PushBack
    Console.WriteLine("Service said: " & msg)
    Me.WriteHeaders(OperationContext.Current.IncomingMessageHeaders)
    Me.wait.Set()
  End Sub

  Private Sub WriteHeaders(ByVal headers As MessageHeaders)
    Console.ForegroundColor = ConsoleColor.Red
    Console.WriteLine("IncomingHeader:")
    Console.ForegroundColor = ConsoleColor.Blue
    For Each h As MessageHeaderInfo In headers
      If Not h.Actor.Equals(String.Empty) Then
        Console.WriteLine(vbTab & h.Actor)
      End If
      Console.ForegroundColor = ConsoleColor.White
      Console.WriteLine(vbTab & h.Name)
      Console.ForegroundColor = ConsoleColor.Blue
      Console.WriteLine(vbTab & h.Namespace)
      Console.WriteLine(vbTab & h.Relay)
      If h.IsReferenceParameter = True Then
        Console.WriteLine("IsReferenceParameter header detected: " & h.ToString())
      End If
    Next h
    Console.ResetColor()
  End Sub
  #End Region

End Class

通过使用指定的 OperationContextScope 对象，使用 OperationContext 类创建特定 OperationContext 对象的范围或新的 IContextChannel 对象的范围。 OperationContextScope可以在 Windows Communication Foundation (WCF) 服务或 WCF 客户端应用程序中使用。

OperationContextScope 对象建立了当前操作上下文之后，可以使用 OperationContext 执行以下操作：

• 访问和修改传入和传出消息头和其他属性。

• 访问运行库，包括调度程序、主机、信道和扩展。

• 访问其他类型的上下文，如安全、实例和请求上下文。

• 访问与 OperationContext 对象关联的信道，或（如果信道实现 System.ServiceModel.Channels.ISession）访问关联信道的会话标识符。

创建了 OperationContextScope 后，将存储当前的 OperationContext，并且新的 OperationContext 由 Current 属性所返回。 释放 OperationContextScope 后，将还原原始 OperationContext。