.net - 为什么当我在 WCF 服务中模拟时，当我尝试运行 LINQ to SQL 查询时，我的服务无法加载 System.Transactions？

Question

我有一个 WCF 服务，托管在 IIS 7.0 中，需要运行数据库查询。为了获得执行此操作的正确权限，我在服务中模拟如下:

代码

[OperationBehavior(Impersonation = ImpersonationOption.Allowed)]
public void MyOperation(int arg)

配置

<behavior name="ReceivingServiceBehavior">
    <!-- Other behaviors -->
    <serviceAuthorization impersonateCallerForAllOperations="true" />
</behavior>

当我尝试连接并运行查询时，我得到以下信息:

Exception - System.IO.FileLoadException: Could not load file orassembly 'System.Transactions, Version=2.0.0.0, Culture=neutral,PublicKeyToken=b77a5c561934e089' or one of its dependencies. Either arequired impersonation level was not provided, or the providedimpersonation level is invalid. (Exception from HRESULT: 0x80070542)File name: 'System.Transactions, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' ---> System.Runtime.InteropServices.COMException (0x80070542): Either a required impersonation level was not provided, or the provided impersonation level is invalid. (Exception from HRESULT: 0x80070542)   at System.Data.Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user)   at System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe()   at System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode()   at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)   at System.Data.Linq.DataQuery`1.System.Collections.Generic.IEnumerable.GetEnumerator()   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)   at Fourth.GHS.MessageRelay.RegistrationDBStorage.FindRegistration(SystemKey key)

Answer 1

您的 WCF 客户端是否设置了所需的“允许的模拟级别”:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.serviceModel>

        <!-- .... -->

        <behaviors>
           <endpointBehaviors>
              <behavior name="ImpersonationBehavior">
                 <clientCredentials>
                      <windows allowedImpersonationLevel="Impersonation" />
                 </clientCredentials>
              </behavior>
           </endpointBehaviors>
        </behaviors>
    </system.serviceModel>
</configuration>

如果没有明确指定，则默认设置为识别。查看this blog post了解更多信息。