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,我的服务是否可以加载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.为了获得正确的权限,我在服务中模仿如下:

码

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

组态

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

当我尝试连接并运行我的查询时,我得到以下内容:

Exception - System.IO.FileLoadException: Could not load file or
assembly 'System.Transactions, Version=2.0.0.0, Culture=neutral,
PublicKeyToken=b77a5c561934e089' or one of its dependencies. Either a
required impersonation level was not provided, or the provided
impersonation 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>

默认情况下,如果未明确指定,则将其设置为" 标识".查看此博客文章了解更多信息.

Answer 2

如果您希望以模拟身份执行 SQL 查询，您实际上可能需要启用对 SQL 服务器的委派。查看这篇文章以获取更多信息：

http://msdn.microsoft.com/en-us/library/ms730088.aspx