如何在 WCF 中同时实现会话和事务流

本文关键字：会话 实现 事务 WCF | 更新日期: 2023-09-27 18:35:14

在尝试回答问题时，很明显，我和 OP 都无法同时构建一个既Session又TransactionFlow启用的 WCF 服务 - 我能提供的唯一解决方案是删除TransactionFlow以使 WCF 会话实例化正常工作。

尽管从逻辑上讲，会话持续时间可以想象超过事务（请记住，TransactionFlow可能意味着事务持有宝贵的服务器资源，如数据库锁、消息队列和事务文件系统），但我找不到明确的参考来确认或拒绝同时实现这两个功能的可能性。

所以我的问题是：如何让InstanceContextMode=InstanceContextMode.PerSession和TransactionFlow在 WCF 中同时工作？

尝试了什么：

ITransactionService.cs 

[ServiceContract(SessionMode = SessionMode.Required)]
public interface ITransactionService
{
    [OperationContract(IsInitiating = true, IsTerminating = false)]
    [TransactionFlow(TransactionFlowOption.Mandatory)]
    int Start(int userId);
    [OperationContract(IsInitiating = false, IsTerminating = true)]
    [TransactionFlow(TransactionFlowOption.Mandatory)]
    int Finish(int userId);
}

TransactionService.svc.cs

[ServiceBehavior(InstanceContextMode=InstanceContextMode.PerSession)]
public class TransactionService : ITransactionService
{
    public int count = 0;
    [OperationBehavior(TransactionScopeRequired = true)]
    public int Start(int userId)
    {
        Debug.Assert(Transaction.Current != null, "No Transaction!");
        count = count + 1;
        return count;
    }
    [OperationBehavior(TransactionScopeRequired = true)]
    public int Finish(int userId)
    {
        Debug.Assert(Transaction.Current != null, "No Transaction!");
        Debug.Assert(count > 0, "No Session!");
        return count;
    }

客户端.cs

  using (var ts = new TransactionScope())
  using (var svc = new TransactionServiceClient())
  {
      svc.Start(0);
      svc.Finish(0);
      ts.Complete();
  }

Service web.config

  <services>
      <service name="WcfLibrary1.TransactionService">
          <endpoint address="" binding="wsHttpBinding"
          contract="WcfLibrary1.ITransactionService">
              <identity>
                  <dns value="localhost" />
              </identity>
          </endpoint>
      </service>
  </services>
   <bindings>
       <wsHttpBinding>
           <binding transactionFlow="true"/>
       </wsHttpBinding>
   </bindings>
   <protocolMapping>
       <remove scheme="http" />
       <add scheme="http" binding="wsHttpBinding" bindingConfiguration="transactionFlowEnabled"/>
   </protocolMapping>

客户端网络.config

<bindings>
    <wsHttpBinding>
        <binding name="WSHttpBinding_ITransactionService" transactionFlow="true" />
    </wsHttpBinding>
</bindings>
<client>
    <endpoint address="http://localhost:65171/TransactionService.svc"
        binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_ITransactionService"
        contract="TransactionService.ITransactionService" name="WSHttpBinding_ITransactionService">
        <identity>
            <dns value="localhost" />
        </identity>
    </endpoint>
</client>

如何在 WCF 中同时实现会话和事务流

经过一些试验和错误，这似乎是可能的。问题似乎是TransactionFlow的默认行为应用以下默认设置：

  • 在类的服务行为属性上 - ReleaseServiceInstanceOnTransactionComplete = true
  • 在方法的操作协定属性上 - TransactionAutoComplete = true

当它们相互结合使用时，将导致释放服务的实例，从而破坏现有会话中保留的任何状态。

禁用以下任一选项将使服务实例在会话期间保持活动状态，从而允许同时使用TransactionFlow和Session：

即在ServiceContract：

[ServiceContract(SessionMode = SessionMode.Required)]
public interface ITransactionService
{
    [OperationContract(IsInitiating = true, IsTerminating = false)]
    [TransactionFlow(TransactionFlowOption.Mandatory)]
    int Start(int userId);
    [OperationContract(IsInitiating = false, IsTerminating = true)]
    [TransactionFlow(TransactionFlowOption.Mandatory)]
    int Finish(int userId);
}

在服务类上更改此项：

[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession,
                 ReleaseServiceInstanceOnTransactionComplete = false)]
public class TransactionService : ITransactionService
{

或者，在操作上：

    [OperationBehavior(TransactionScopeRequired = true, 
                       TransactionAutoComplete = false)]
    public int Start(int userId)
    {
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