ServiceBehaviorAttribute.TransactionIsolationLevel 属性

定义

命名空间:

System.ServiceModel

程序集:

System.ServiceModel.dll

指定服务中新创建的事务和客户端传入的流事务的事务隔离级别。

public:
 property System::Transactions::IsolationLevel TransactionIsolationLevel { System::Transactions::IsolationLevel get(); void set(System::Transactions::IsolationLevel value); };

public System.Transactions.IsolationLevel TransactionIsolationLevel { get; set; }

member this.TransactionIsolationLevel : System.Transactions.IsolationLevel with get, set

Public Property TransactionIsolationLevel As IsolationLevel

属性值

IsolationLevel

一个 IsolationLevel 值，指定事务的隔离级别。 默认值为 Unspecified。

例外

ArgumentOutOfRangeException

该值不是 IsolationLevel 值之一。

示例

下面的代码示例将事务隔离级别设置为 ReadCommitted，不支持并发事务，并要求调用方法来进行流事务。如果未发生未经处理的异常则自动提交事务。

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
   *   -- Does not release the service object when the transaction commits
   *   -- The isolation level is read committed.
   */
  [ServiceBehavior(
    ConcurrencyMode=ConcurrencyMode.Single,
    InstanceContextMode=InstanceContextMode.PerSession,
    ReleaseServiceInstanceOnTransactionComplete=false,
    TransactionIsolationLevel=System.Transactions.IsolationLevel.ReadCommitted
  )]
  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:
     *   -- Always executes under a transaction scope.
     *   -- The transaction scope is completed when the operation terminates
     *       without an unhandled exception.
     */
    [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
'   *   -- Does not release the service object when the transaction commits
'   *   -- The isolation level is read committed.
'   
    <ServiceBehavior(ConcurrencyMode:=ConcurrencyMode.Single, InstanceContextMode:=InstanceContextMode.PerSession, _
      ReleaseServiceInstanceOnTransactionComplete:=False, TransactionIsolationLevel:=System.Transactions.IsolationLevel.ReadCommitted)> _
    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:
        '     *   -- Always executes under a transaction scope.
        '     *   -- The transaction scope is completed when the operation terminates
        '     *       without an unhandled exception.
        '     
        <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

为了正确执行下面的代码示例，基础绑定必须支持流事务。 例如，若要使用 WSHttpBinding 支持流事务，请在代码或应用程序配置文件中将 TransactionFlow 属性设置为 true。 下面的代码示例演示上述示例的配置文件。

<configuration>
  <system.serviceModel>
    <services>
      <service  
        name="Microsoft.WCF.Documentation.BehaviorService" 
        behaviorConfiguration="mex"
        >
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8080/BehaviorService"/>
            <add baseAddress="net.tcp://localhost:8081/BehaviorService"/>
          </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"
          />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="mex">
          <serviceMetadata httpGetEnabled="true"/>
        </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>

注解

运行事务时所采用的隔离级别可确定在其他事务中进行更改时处理数据的方式，以及事务必须保持锁定以保护数据不被更改的时间长度。 例如，默认值 Unspecified 指定在事务完成之前不允许进行更新或插入。

此属性也可以用于限制客户端传入的流事务的隔离级别。