// -------- Service1 ----------------- [ServiceContract] public interface IService1 {   [OperationContract]   [TransactionFlow(TransactionFlowOption.Allowed)]   void Test(); } public class MyService1 : IService1 {   [OperationBehavior(TransactionScopeRequired=true)]   public void Test()   {     string connStr = "server=(local);uid=sa;pwd=sa;database=temp";     using (SqlConnection conn = new SqlConnection(connStr))     {       conn.Open();       SqlCommand cmd = new SqlCommand("insert into [User] ([name]) values (@name)",         conn);       cmd.Parameters.Add(new SqlParameter("@name", "ZhangSan"));       cmd.ExecuteNonQuery();     }   } } // -------- Service2 ----------------- [ServiceContract] public interface IService2 {   [OperationContract]   [TransactionFlow(TransactionFlowOption.Allowed)]   void Test(); } public class MyService2 : IService2 {   [OperationBehavior(TransactionScopeRequired = true)]   public void Test()   {     string connStr = "server=(local);uid=sa;pwd=sa;database=temp";     using (SqlConnection conn = new SqlConnection(connStr))     {       conn.Open();       SqlCommand cmd = new SqlCommand("insert into Account ([user], [money]) values (@user, @money)",         conn);       cmd.Parameters.Add(new SqlParameter("@user", "ZhangSan"));       cmd.Parameters.Add(new SqlParameter("@money", 100));       cmd.ExecuteNonQuery();     }   } } public class WcfTest {   public static void Test()   {     // -------- Host -----------------     AppDomain.CreateDomain("Server").DoCallBack(delegate     {       NetTcpBinding bindingServer = new NetTcpBinding();       bindingServer.TransactionFlow = true;       ServiceHost host1 = new ServiceHost(typeof(MyService1), new Uri("net.tcp://localhost:8080"));       host1.AddServiceEndpoint(typeof(IService1), bindingServer, "");       host1.Open();       ServiceHost host2 = new ServiceHost(typeof(MyService2), new Uri("net.tcp://localhost:8081"));       host2.AddServiceEndpoint(typeof(IService2), bindingServer, "");       host2.Open();     });     // -------- Client -----------------     NetTcpBinding bindingClient = new NetTcpBinding();     bindingClient.TransactionFlow = true;     IService1 client1 = ChannelFactory<IService1>.CreateChannel(bindingClient,       new EndpointAddress("net.tcp://localhost:8080"));     IService2 client2 = ChannelFactory<IService2>.CreateChannel(bindingClient,       new EndpointAddress("net.tcp://localhost:8081"));     using (TransactionScope scope = new TransactionScope())     {       try       {         client1.Test();         client2.Test();         scope.Complete();       }       finally       {         (client1 as IDisposable).Dispose();         (client2 as IDisposable).Dispose();       }     }   } }