WebService连接Access数据库的问题.急~~~~~~~~~~~~~~

Question

报错:没有可用的错误消息，结果代码: E_NOINTERFACE(0x80004002)。

Answer 1

捕捉到 System.Data.OleDb.OleDbException
  Message="没有可用的错误消息，结果代码: E_NOINTERFACE(0x80004002)。"
  Source="System.Data"
  ErrorCode=-2147467262
  StackTrace:
       在 System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
       在 System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup)
       在 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
       在 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
       在 System.Data.OleDb.OleDbConnection.Open()
       在 Service.ReadNum(String oid, String pass) 位置 d:\Backup\我的文档\Visual Studio 2005\WebSites\Verification\App_Code\Service.cs:行号 117

Answer 2

不会是没加名称空间吧
using System.Data.OledbClient;

Answer 3

加了using System.Data.OleDb