C# 建立…时发生与网络相关或特定于实例的错误。。。。错误：26

我在我的asp.net项目中工作；当我运行我的程序时，它停止运行并向我发送以下消息：

建立与SQL Server的连接时发生与网络相关或特定于实例的错误。找不到服务器或无法访问服务器。验证实例名称是否正确，以及SQL Server是否配置为允许远程连接。（提供程序：SQL网络接口，错误：26-定位指定的服务器/实例时出错）

“/Test2”应用程序中出现服务器错误。

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

Source Error:


Line 27:         string cmdString = "Delete from tblSessionCart";
Line 28:         SqlCommand cmd = new SqlCommand(cmdString, conn);
Line 29:         conn.Open();
Line 30:         try
Line 31:         {


Source File: c:\Users\mousa\Desktop\Test2\App_Code\clsSessionCart.cs    Line: 29

Stack Trace:

[SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)]
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4876455
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194
   System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) +354
   System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +90
   System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +401
   System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +225
   System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +189
   System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +4889331
   System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +31
   System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +431
   System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
   System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +499
   System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +65
   System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +117
   System.Data.SqlClient.SqlConnection.Open() +122
   clsSessionCart.DeleteCart() in c:\Users\mousa\Desktop\Test2\App_Code\clsSessionCart.cs:29
   ASP.global_asax.Session_Start(Object sender, EventArgs e) in c:\Users\mousa\Desktop\Test2\Global.asax:27
   System.Web.SessionState.SessionStateModule.RaiseOnStart(EventArgs e) +8878884
   System.Web.SessionState.SessionStateModule.CompleteAcquireState() +237
   System.Web.SessionState.SessionStateModule.BeginAcquireState(Object source, EventArgs e, AsyncCallback cb, Object extraData) +504
   System.Web.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +66
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155


Version Information: Microsoft .NET Framework Version:2.0.50727.5477; ASP.NET Version:2.0.50727.5479 

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此问题与连接字符串有关

检查实例服务器

检查用户和密码

连接字符串：

如果您有实例，请确保在服务器中指定了实例，例如：

---

Server=。\SQL2008

当sqlServer服务停止或TCP端口更改时，会引发此异常，请检查该异常。

我们将端口信息添加到连接字符串中，从而缓解了此错误。例如：

---

服务器=服务器名，端口#；数据库=数据库名称

我得到错误是因为我的

数据源

被命名为

（localdb）\v11.0

在C#中，反斜杠被解释为一个特殊字符，因此需要按如下方式进行转义：下面几行就可以了！但是单个“\”失败了

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我得到了相同的错误，我的连接字符串是正确的。我尝试使用SQL Server的ip地址而不是服务器名称。最后，这个错误消失了

我使用这个连接字符串

 <add name="YourEntitiesName" connectionString="metadata=res://*/Model.SampleDatabaseModel.csdl|res://*/Model.SampleDatabaseModel.ssdl|res://*/Model.SampleDatabaseModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=10.123.60.12\SQLServerName;initial catalog=SampleDB;user id=sa;password=123456;MultipleActiveResultSets=True;Pooling=False;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

而不是

<add name="YourEntitiesName" connectionString="metadata=res://*/Model.SampleDatabaseModel.csdl|res://*/Model.SampleDatabaseModel.ssdl|res://*/Model.SampleDatabaseModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=SERVER01\SQLServerName;initial catalog=SampleDB;user id=sa;password=123456;MultipleActiveResultSets=True;Pooling=False;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

您的SQL Server未设置为接受远程连接。看到了吗？你能显示你的连接字符串吗？此问题与您的连接字符串有关。我收到相同的错误，但会间歇性发生。有什么想法吗？可能是重复的

 <add name="YourEntitiesName" connectionString="metadata=res://*/Model.SampleDatabaseModel.csdl|res://*/Model.SampleDatabaseModel.ssdl|res://*/Model.SampleDatabaseModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=10.123.60.12\SQLServerName;initial catalog=SampleDB;user id=sa;password=123456;MultipleActiveResultSets=True;Pooling=False;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

<add name="YourEntitiesName" connectionString="metadata=res://*/Model.SampleDatabaseModel.csdl|res://*/Model.SampleDatabaseModel.ssdl|res://*/Model.SampleDatabaseModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=SERVER01\SQLServerName;initial catalog=SampleDB;user id=sa;password=123456;MultipleActiveResultSets=True;Pooling=False;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />