如何:创建要求会话的服务How to: Create a Service That Requires Sessions

会话在两个或更多终结点之间创建一个共享状态,从而启用一些有用的功能,例如回调、多跳安全性以及客户端和服务实例之间的关联。Sessions create a shared state between two or more endpoints that enables useful features such as callbacks, multi-hop security, and associations between clients and service instances. 有关在 Windows Communication Foundation (WCF) 应用程序中的会话的详细信息,请参阅使用会话的For more information about sessions in Windows Communication Foundation (WCF) applications, see Using Sessions.

指定协定需要其绑定来支持会话To specify that a contract require its binding to support sessions

  1. 创建至少包含一个操作的服务协定。Create a service contract with at least one operation. 有关如何创建服务协定的示例,请参阅如何:定义服务协定For an example of how to create a service contract, see How to: Define a Service Contract.

  2. 修改声明协定的 System.ServiceModel.ServiceContractAttribute,将 ServiceContractAttribute.SessionMode 属性设置为:Modify the System.ServiceModel.ServiceContractAttribute that declares the contract by setting the ServiceContractAttribute.SessionMode property to either:

  3. 配置服务终结点以使用支持会话的绑定。Configure your service endpoint to use a binding that supports sessions. 下面的配置示例演示了支持 WSSystem.ServiceModel.WSDualHttpBindingReliableMessaging 会话的 - 的用法。The following configuration example shows the use of the System.ServiceModel.WSDualHttpBinding, which supports a WS-ReliableMessaging session.

    <appSettings>
      <!-- use appSetting to configure base address provided by host -->
      <add key="baseAddress" value="http://localhost:8080/ServiceMetadata" />
    </appSettings>
    <system.serviceModel>
      <services>
        <service 
          name="Microsoft.WCF.Documentation.DuplexHello"
          behaviorConfiguration="mex"
        >
          <endpoint
            address="/DuplexService"
            binding="wsDualHttpBinding"
            contract="Microsoft.WCF.Documentation.IDuplexHello"
           />
          <endpoint
            address=""
            binding="mexHttpBinding"
            contract="IMetadataExchange"
          />
        </service>
      </services>
      <behaviors>
        <serviceBehaviors>
          <behavior name="mex" >
            <serviceMetadata httpGetEnabled="true" />
          </behavior>
        </serviceBehaviors>
      </behaviors>
    </system.serviceModel>
    

示例Example

下面的示例代码演示如何指定协定级别会话需求并使用配置文件来支持 System.ServiceModel.WSDualHttpBinding 绑定的需求。The following example code shows how to specify a contract-level session requirement and use a configuration file to support that requirement with the System.ServiceModel.WSDualHttpBinding binding.

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);
  }

  [ServiceBehaviorAttribute(InstanceContextMode=InstanceContextMode.PerSession)]
  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);
    }
  }
}


Imports System.Collections.Generic
Imports System.ServiceModel
Imports System.Threading

Namespace Microsoft.WCF.Documentation
    <ServiceContract(Name:="SampleDuplexHello", Namespace:="http://microsoft.wcf.documentation", _
                     CallbackContract:=GetType(IHelloCallbackContract), SessionMode:=SessionMode.Required)> _
    Public Interface IDuplexHello
        <OperationContract(IsOneWay:=True)> _
        Sub Hello(ByVal greeting As String)
    End Interface

  Public Interface IHelloCallbackContract
    <OperationContract(IsOneWay := True)> _
    Sub Reply(ByVal responseToGreeting As String)
  End Interface

  <ServiceBehaviorAttribute(InstanceContextMode:=InstanceContextMode.PerSession)> _
  Public Class DuplexHello
      Implements IDuplexHello

    Public Sub New()
      Console.WriteLine("Service object created: " & Me.GetHashCode().ToString())
    End Sub

    Protected Overrides Sub Finalize()
      Console.WriteLine("Service object destroyed: " & Me.GetHashCode().ToString())
    End Sub

    Public Sub Hello(ByVal greeting As String) Implements IDuplexHello.Hello
      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)
      Dim callerProxy As IHelloCallbackContract = OperationContext.Current.GetCallbackChannel(Of IHelloCallbackContract)()
            Dim response = "Service object " & Me.GetHashCode().ToString() & " received: " & greeting
      Console.WriteLine("Sending back: " & response)
      callerProxy.Reply(response)
    End Sub
  End Class
End Namespace
<appSettings>
  <!-- use appSetting to configure base address provided by host -->
  <add key="baseAddress" value="http://localhost:8080/ServiceMetadata" />
</appSettings>
<system.serviceModel>
  <services>
    <service 
      name="Microsoft.WCF.Documentation.DuplexHello"
      behaviorConfiguration="mex"
    >
      <endpoint
        address="/DuplexService"
        binding="wsDualHttpBinding"
        contract="Microsoft.WCF.Documentation.IDuplexHello"
       />
      <endpoint
        address=""
        binding="mexHttpBinding"
        contract="IMetadataExchange"
      />
    </service>
  </services>
  <behaviors>
    <serviceBehaviors>
      <behavior name="mex" >
        <serviceMetadata httpGetEnabled="true" />
      </behavior>
    </serviceBehaviors>
  </behaviors>
</system.serviceModel>

请参阅See also