c#网站开发：提示用户 'sa' 登录失败。原因: 未与信任 SQL Server 连接相关联。 请教高手怎么解决？

应用程序中的服务器错误。
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用户 'sa' 登录失败。原因: 未与信任 SQL Server 连接相关联。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.Data.SqlClient.SqlException: 用户 'sa' 登录失败。原因: 未与信任 SQL Server 连接相关联。

源错误:


行 92:
行 93: if (con.State != ConnectionState.Open)
行 94: con.Open();
行 95: cmd.Connection = con;
行 96: cmd.CommandText = nText;


源文件: f:\WebSite7\App_Code\SqlHelper.cs 行: 94

堆栈跟踪:


[SqlException (0x80131904): 用户 'sa' 登录失败。原因: 未与信任 SQL Server 连接相关联。]
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +171
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +199
System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2406
System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) +34
System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +223
System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +371
System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +184
System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +193
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +502
System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +28
System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +429
System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +70
System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +510
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +85
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +89
System.Data.SqlClient.SqlConnection.Open() +160
SqlHelper.PrepareCommand(SqlConnection con, SqlCommand cmd, SqlTransaction trans, CommandType nType, String nText, SqlParameter[] paras) in f:\WebSite7\App_Code\SqlHelper.cs:94
SqlHelper.ExcuteRead(String nText, CommandType nType, SqlParameter[] paras) in f:\WebSite7\App_Code\SqlHelper.cs:33

[Exception: 用户 'sa' 登录失败。原因: 未与信任 SQL Server 连接相关联。]
SqlHelper.ExcuteRead(String nText, CommandType nType, SqlParameter[] paras) in f:\WebSite7\App_Code\SqlHelper.cs:41
_Default.BindProduct() in f:\WebSite7\Default.aspx.cs:31
_Default.Page_Load(Object sender, EventArgs e) in f:\WebSite7\Default.aspx.cs:20
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +13
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +45
System.Web.UI.Control.OnLoad(EventArgs e) +80
System.Web.UI.Control.LoadRecursive() +49
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3745