OperationContextScope Class

Definition

Namespace:

System.ServiceModel

Assembly:

System.ServiceModel.Primitives.dll

Package:

System.ServiceModel.Primitives v8.0.0

Source:

OperationContextScope.cs

Creates a block within which an OperationContext object is in scope.

public ref class OperationContextScope sealed : IDisposable

public sealed class OperationContextScope : IDisposable

type OperationContextScope = class
    interface IDisposable

Public NotInheritable Class OperationContextScope
Implements IDisposable

Inheritance

Object

OperationContextScope

Implements

IDisposable

Examples

The following example shows how to use the OperationContextScope to create a new context in a client application to add a custom header to the outgoing message.

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 == true)
      {
        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

Remarks

Use the OperationContextScope class to create a scope for a specific OperationContext object or a scope for a new OperationContext object using a specified IContextChannel object. An OperationContextScope can be used in a Windows Communication Foundation (WCF) service or WCF client application.

Once the OperationContextScope object has established the current operation context, you can use the OperationContext to:

• Access and modify incoming and outgoing message headers and other properties.

• Access the runtime, including dispatchers, the host, channel, and extensions.

• Access other types of contexts, such as security, instance, and request contexts.

• Access the channel associated with the OperationContext object or (if the channel implements System.ServiceModel.Channels.ISession) the associated channel's session identifier.

When an OperationContextScope is created, the current OperationContext is stored and the new OperationContext becomes the one returned by the Current property. When the OperationContextScope is disposed, the original OperationContext is restored.

Warning

Do not use the asynchronous "await" pattern within a OperationContextScope block. When the continuation occurs, it may run on a different thread and OperationContextScope is thread specific. If you need to call "await" for an async call, use it outside of the OperationContextScope block.

Constructors

OperationContextScope(IContextChannel)	Initializes a new instance of the OperationContextScope class that uses the specified IContextChannel to create a new OperationContext for the scope.
OperationContextScope(OperationContext)	Initializes a new instance of the OperationContextScope class to create a scope for the specified OperationContext object.

Methods

Dispose()	Restores the original OperationContext to the active context and recycles the OperationContextScope object.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)