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OperationContext Class

Provides access to the execution context of a service method.

Namespace: System.ServiceModel
Assembly: System.ServiceModel (in system.servicemodel.dll)

public sealed class OperationContext : IExtensibleObject<OperationContext>
public final class OperationContext implements IExtensibleObject<OperationContext>
public final class OperationContext implements IExtensibleObject<OperationContext>
Not applicable.

Use the OperationContext from within a service operation to access the current operation execution environment. In particular, the operation context is used to access callback channels in duplex services, to store extra state data across portions of the operations, and to access incoming message headers and properties as well as add outgoing message headers and properties.

For more information about using extensions to store state data, see Extensible Objects.

The OperationContext has the following properties and methods.

The following code example uses the Current property and GetCallbackChannel method to obtain the channel back to the caller from within a method. All methods in this example are one-way methods, enabling the service and the client to communicate in both directions independently. In this case, the example client application expects only one return call before it exits, but another client, for example a Windows Forms client, can receive any number of calls from the service.

using System;
using System.Collections.Generic;
using System.ServiceModel;
using System.Threading;

namespace Microsoft.WCF.Documentation
{
  [ServiceContract(
    Name = "SampleDuplexHello",
    Namespace = "http://microsoft.wcf.documentation",
    CallbackContract = typeof(IHelloCallbackContract),
    SessionMode = SessionMode.Required
  )]
  public interface IDuplexHello
  {
    [OperationContract(IsOneWay = true)]
    void Hello(string greeting);
  }

  public interface IHelloCallbackContract
  {
    [OperationContract(IsOneWay = true)]
    void Reply(string responseToGreeting);
  }

  public class DuplexHello : IDuplexHello
  {
    public DuplexHello()
    {
      Console.WriteLine("Service object created: " + this.GetHashCode().ToString());
    }

    ~DuplexHello()
    {
      Console.WriteLine("Service object destroyed: " + this.GetHashCode().ToString());
    }

    public void Hello(string greeting)
    {
      Console.WriteLine("Caller sent: " + greeting);
      Console.WriteLine("Session ID: " + OperationContext.Current.SessionId);
      Console.WriteLine("Waiting two seconds before returning call.");
      // Put a slight delay to demonstrate asynchronous behavior on client.
      Thread.Sleep(2000);
      IHelloCallbackContract callerProxy
        = OperationContext.Current.GetCallbackChannel<IHelloCallbackContract>();
      string response = "Service object " + this.GetHashCode().ToString() + " received: " + greeting;
      Console.WriteLine("Sending back: " + response);
      callerProxy.Reply(response);
    }
  }
}

The following client implements the SampleDuplexHelloCallback to receive the callback message. The imported callback contract is not the same name as the one in the service, due to the use of the Name property in the preceding example. Note that the client makes no assumptions about whether or when it might receive a callback; the server callback is entirely independent of the client's outbound call.

NoteNote:

For an example that uses the OperationContext class in a client scenario, see OperationContextScope.

System.Object
  System.ServiceModel.OperationContext

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

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0

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