WCF 分散式開發常見錯誤 (14)：InvalidOperationException —— TransactionFlow Mandatory 需 Binding 支援 TransactionFlowBindingElement

服務合約標記 [TransactionFlow(TransactionFlowOption.Mandatory)]，但端點繫結未啟用交易流，拋出：「At least one operation... Mandatory but the channel's binding 'NetTcpBinding' is not configured with a TransactionFlowBindingElement」。

設定檔修正

<bindings>
  <netTcpBinding>
    <binding name="netTcpBindingTcp" transactionFlow="true" transactionProtocol="WSAtomicTransactionOctober2004">
      <security mode="None" />
    </binding>
  </netTcpBinding>
</bindings>

<endpoint address="net.tcp://localhost:9002/WCFServiceTransaction2"
          binding="netTcpBinding"
          bindingConfiguration="netTcpBindingTcp"
          contract="WCFService.IWCFServiceTransaction2" />

關鍵：transactionFlow="true" 啟用 TransactionFlowBindingElement，transactionProtocol 指定協定版本。程式碼建立繫結同樣需設定 TransactionFlowBindingElement。