ServiceBehaviorAttribute.InstanceContextMode 屬性

參考

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，這個值會指出何時建立新的服務物件。

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

該值不是其中一個 InstanceContextMode 值。

範例

下列程式碼範例會示範 ServiceBehaviorAttribute 屬性。 BehaviorService 類別會使用 ServiceBehaviorAttribute 屬性指出：

實作方法會在 UI 執行緒上叫用。
每個工作階段都有一個服務物件。
該服務為單一執行緒服務，而且不支援可重新進入的呼叫。

此外，位於作業層級的 OperationBehaviorAttribute 值表示 TxWork 方法會自動登記在流動異動中或建立新異動來執行工作，並且表示如果沒有發生未處理的例外狀況，則會自動認可這項異動。

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

基礎繫結必須支援流動交易，才能讓下列程式碼範例正確執行。例如，若要使用 WSHttpBinding 支援流動的交易，請透過程式碼或應用程式組態檔，將 TransactionFlow 屬性設定為 true。下列程式碼範例會顯示先前範例的組態檔。

<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 InstanceContextMode 屬性，即可指定建立新服務物件的時機。由於服務物件不是直接連接至通訊通道，因此服務物件的存留期與用戶端和服務應用程式之間的通道的存留期無關。預設值 PerSession，會在用戶端和服務應用程式之間建立新通訊工作階段時，指示服務應用程式建立新的服務物件。在相同工作階段中的後續呼叫會由相同物件處理。

PerSession 表示每個服務物件都會處理來自一個用戶端通道的要求。

注意

InstanceContextMode 屬性會與其他設定互動。例如，如果 InstanceContextMode 值是設定為 Single，這時除非您也將 ConcurrencyMode 值設定為 Multiple，否則您的服務一次只能處理一個訊息。這個屬性也會產生與 ServiceContractAttribute.SessionMode 屬性一起使用的行為。如需詳細資訊，請參閱會話、實例和並行。

對於單一存留期行為 (例如，如果主應用程式呼叫 ServiceHost 建構函式，並傳遞物件做為服務使用)，服務類別必須將 InstanceContextMode 設定為 Single，否則會在執行階段擲回例外狀況。

適用於

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

其他資源