在 System.Web.UI.Page.HandleError(Exception e)
   在 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   在 System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   在 System.Web.UI.Page.ProcessRequest()
   在 System.Web.UI.Page.ProcessRequest(HttpContext context)
   在 ASP.index_aspx.ProcessRequest(HttpContext context)
   在 System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   在 System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
   在 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

System.Reflection.TargetInvocationException: 调用的目标发生了异常。 ---> System.Data.SqlClient.SqlException: 在与 SQL Server 建立连接时出现与网络相关的或特定于实例的错误。未找到或无法访问服务器。请验证实例名称是否正确并且 SQL Server 已配置为允许远程连接。 (provider: Named Pipes Provider, error: 40 - 无法打开到 SQL Server 的连接) ---> System.ComponentModel.Win32Exception: 找不到网络路径。
   --- 内部异常堆栈跟踪的结尾 ---
   在 System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   在 System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   在 System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   在 System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   在 System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   在 System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   在 System.Data.SqlClient.SqlConnection.Open()
   在 Kesion.DataBase.DBHelper.ExecuteDataset(String connectionString, CommandType commandType, String commandText, DbParameter[] commandParameters)
   在 Kesion.SqlDAL.DataFactory.GetDataTable(String sqlstr)
   在 Kesion.Cache.MyCache.GetAllNavigationLabelCache()
   在 Kesion.HtmlTags.Primary.Navigation.Run(String& F_C)
   在 Kesion.Controllers.courseController.DoTCListSearch(String& F_C, Boolean isMobileDevice, Boolean isSchool)
   在 Kesion.Controllers.courseController.TeacherList(Boolean isMobileDevice, Boolean isSchool)
   在 Kesion.Controllers.courseController.doRun(String a, Boolean isMobileDevice, Boolean isSchool)
   --- 内部异常堆栈跟踪的结尾 ---
   在 System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   在 System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   在 System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   在 Kesion.NET.WebSite.Index.Page_Load(Object sender, EventArgs e)
   在 System.Web.UI.Control.OnLoad(EventArgs e)
   在 System.Web.UI.Control.LoadRecursive()
   在 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)