ServiceBehaviorAttribute.InstanceContextMode 屬性

定義

命名空間:: System.ServiceModel

組件:: System.ServiceModel.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

取得或設定值，指示新服務物件何時建立。

public:
 property System::ServiceModel::InstanceContextMode InstanceContextMode { System::ServiceModel::InstanceContextMode get(); void set(System::ServiceModel::InstanceContextMode value); };

public System.ServiceModel.InstanceContextMode InstanceContextMode { get; set; }

member this.InstanceContextMode : System.ServiceModel.InstanceContextMode with get, set

Public Property InstanceContextMode As InstanceContextMode

屬性值

InstanceContextMode

其中一個 InstanceContextMode 值;預設值為 PerSession。

例外狀況

ArgumentOutOfRangeException

價值不是其中 InstanceContextMode 之一。

範例

以下程式碼範例展示了這些 ServiceBehaviorAttribute 特性。該 BehaviorService 類別使用屬性 ServiceBehaviorAttribute 來表示：

實作方法會在 UI 執行緒中被調用。
每個會話有一個服務物件。
該服務為單執行緒，不支援重入呼叫。

此外，在操作層級，這些 OperationBehaviorAttribute 值表示方法 TxWork 會自動登錄流交易或建立新交易來執行，且如果未發生未處理異常，交易會自動提交。

using System;
using System.ServiceModel;
using System.Transactions;

namespace Microsoft.WCF.Documentation
{
  [ServiceContract(
    Namespace="http://microsoft.wcf.documentation",
    SessionMode=SessionMode.Required
  )]
  public interface IBehaviorService
  {
    [OperationContract]
    string TxWork(string message);
  }

  // Note: To use the TransactionIsolationLevel property, you
  // must add a reference to the System.Transactions.dll assembly.
  /* The following service implementation:
   *   -- Processes messages on one thread at a time
   *   -- Creates one service object per session
   *   -- Releases the service object when the transaction commits
   */
  [ServiceBehavior(
    ConcurrencyMode=ConcurrencyMode.Single,
    InstanceContextMode=InstanceContextMode.PerSession,
    ReleaseServiceInstanceOnTransactionComplete=true
  )]
  public class BehaviorService : IBehaviorService, IDisposable
  {
    Guid myID;

    public BehaviorService()
    {
      myID = Guid.NewGuid();
      Console.WriteLine(
        "Object "
        + myID.ToString()
        + " created.");
    }

    /*
     * The following operation-level behaviors are specified:
     *   -- The executing transaction is committed when
     *        the operation completes without an
     *        unhandled exception
     *   -- Always executes under a flowed transaction.
     */
    [OperationBehavior(
      TransactionAutoComplete = true,
      TransactionScopeRequired = true
    )]
    [TransactionFlow(TransactionFlowOption.Mandatory)]
    public string TxWork(string message)
    {
      // Do some transactable work.
      Console.WriteLine("TxWork called with: " + message);
      // Display transaction information.

      TransactionInformation info = Transaction.Current.TransactionInformation;
      Console.WriteLine("The distributed tx ID: {0}.", info.DistributedIdentifier);
      Console.WriteLine("The tx status: {0}.", info.Status);
      return String.Format("Hello. This was object {0}.",myID.ToString()) ;
    }

    public void Dispose()
    {
      Console.WriteLine(
        "Service "
        + myID.ToString()
        + " is being recycled."
      );
    }
  }
}

Imports System.ServiceModel
Imports System.Transactions

Namespace Microsoft.WCF.Documentation
  <ServiceContract(Namespace:="http://microsoft.wcf.documentation", SessionMode:=SessionMode.Required)> _
  Public Interface IBehaviorService
    <OperationContract> _
    Function TxWork(ByVal message As String) As String
  End Interface

  ' Note: To use the TransactionIsolationLevel property, you 
  ' must add a reference to the System.Transactions.dll assembly.
'   The following service implementation:
'   *   -- Processes messages on one thread at a time
'   *   -- Creates one service object per session
'   *   -- Releases the service object when the transaction commits
'   
    <ServiceBehavior(ConcurrencyMode:=ConcurrencyMode.Single, InstanceContextMode:=InstanceContextMode.PerSession, _
                     ReleaseServiceInstanceOnTransactionComplete:=True)> _
    Public Class BehaviorService
        Implements IBehaviorService, IDisposable
        Private myID As Guid

        Public Sub New()
            myID = Guid.NewGuid()
            Console.WriteLine("Object " & myID.ToString() & " created.")
        End Sub

        '    
        '     * The following operation-level behaviors are specified:
        '     *   -- The executing transaction is committed when
        '     *        the operation completes without an 
        '     *        unhandled exception
        '     *   -- Always executes under a flowed transaction.
        '     
        <OperationBehavior(TransactionAutoComplete:=True, TransactionScopeRequired:=True), TransactionFlow(TransactionFlowOption.Mandatory)> _
        Public Function TxWork(ByVal message As String) As String Implements IBehaviorService.TxWork
            ' Do some transactable work.
            Console.WriteLine("TxWork called with: " & message)
            ' Display transaction information.

            Dim info As TransactionInformation = Transaction.Current.TransactionInformation
            Console.WriteLine("The distributed tx ID: {0}.", info.DistributedIdentifier)
            Console.WriteLine("The tx status: {0}.", info.Status)
            Return String.Format("Hello. This was object {0}.", myID.ToString())
        End Function

        Public Sub Dispose() Implements IDisposable.Dispose
            Console.WriteLine("Service " & myID.ToString() & " is being recycled.")
        End Sub
    End Class
End Namespace

底層綁定必須支援流式交易，才能讓以下程式碼範例正確執行。若要支援流式交易， WSHttpBinding例如，請將屬性設 TransactionFlow 為程式碼 true 中或應用程式設定檔中。以下程式碼範例展示了前述範例的設定檔。

<configuration>
  <system.serviceModel>
    <services>
      <service  
        name="Microsoft.WCF.Documentation.BehaviorService" 
        behaviorConfiguration="metadataAndDebugEnabled"
      >
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8080/SampleService"/>
          </baseAddresses>
        </host>
        <!--
          Note:
            This example code uses the WSHttpBinding to support transactions using the 
            WS-AtomicTransactions (WS-AT) protocol. WSHttpBinding is configured to use the  
            protocol, but the protocol is not enabled on some computers. Use the xws_reg -wsat+ 
            command to enable the WS-AtomicTransactions protocol in the MSDTC service.          
          -->
        <endpoint 
           contract="Microsoft.WCF.Documentation.IBehaviorService"
           binding="wsHttpBinding"
           bindingConfiguration="wsHttpBindingWithTXFlow"
           address="http://localhost:8080/BehaviorService"
          />
        <endpoint 
           contract="Microsoft.WCF.Documentation.IBehaviorService"
           binding="netTcpBinding"
           bindingConfiguration="netTcpBindingWithTXFlow"
           address="net.tcp://localhost:8081/BehaviorService"
          />
        <endpoint
          address="mex"
          binding="mexHttpBinding"
          contract="IMetadataExchange"
        />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="metadataAndDebugEnabled">
          <serviceDebug
            includeExceptionDetailInFaults="true"
          />
          <serviceMetadata
            httpGetEnabled="true"
            httpGetUrl=""
          />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <!-- binding configuration - configures a WSHttpBinding to require transaction flow -->
    <bindings>
      <wsHttpBinding>
        <binding name="wsHttpBindingWithTXFlow" transactionFlow="true" />
      </wsHttpBinding>
      <netTcpBinding>
        <binding name="netTcpBindingWithTXFlow" transactionFlow="true" />
      </netTcpBinding>
    </bindings>
  </system.serviceModel>
</configuration>

備註

使用該 InstanceContextMode 屬性來指定何時建立新的服務物件。由於服務物件並未直接連接到通訊通道，因此服務物件的壽命與用戶端與服務應用程式之間通道的壽命無關。預設值 PerSession，指示服務應用程式在用戶端與服務應用程式之間建立新的通訊會話時建立新的服務物件。同一會話中後續的呼叫由同一物件處理。

PerSession 表示每個服務物件處理來自一個用戶端通道的請求。

備註

該 InstanceContextMode 屬性會與其他設定互動。例如，若值 InstanceContextMode 設定為 Single 結果，則您的服務一次只能處理一則訊息，除非你也將值設 ConcurrencyMode 為 Multiple。此性質同時產生與該 ServiceContractAttribute.SessionMode 性質結合的行為。詳情請參見會話、實例化與並行。

對於單例壽命行為（例如，當主機應用程式呼叫 ServiceHost 建構子並傳遞物件作為服務時），服務類別必須設 InstanceContextMode 為 Single，否則執行時會拋出例外。

適用於

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共用方式為

ServiceBehaviorAttribute.InstanceContextMode 屬性

定義

屬性值

例外狀況

範例

備註

適用於

意見反應