Question

我有一个简单的C＃程序，应该读取XLS文件并将其作为DataTable对象返回。除非在MS Excel中打开相同的文件，否则它无法获取数据 - 同时，在启动程序时。该程序使用Microsoft.Jet.OLEDB.4.0提供程序以及OleDbConnection和OleDbDataAdapter类实例来访问数据：

public class ExcelImport
{
    static public DataTable GetDataTable(string excelFileName, string sqlSelect)
    {
        string tpl = @"Provider=Microsoft.Jet.OLEDB.4.0;Data source={0};Extended Properties=""Excel 8.0;HDR=Yes;""";
        string excelConnectionString = string.Format(tpl, excelFileName);
        using (OleDbConnection connection = new OleDbConnection(excelConnectionString))
        {
            connection.Open();        // <---- here it fails
            using (OleDbDataAdapter adapter = new OleDbDataAdapter(sqlSelect, connection))
            {
                DataTable table = new DataTable();
                adapter.Fill(table);
                return table;
            }
        }
    }
}

电话看起来像这样：

        string fname = @"d:\directory\the_file.xls";
        string sqlcmd = @"
            SELECT
                [Code],
                [Name]
            FROM [Sheet1$]";
        DataTable dt = ExcelImport.GetDataTable(fname, sqlcmd);

当MS Excel（版本2016，如果重要）正在运行时，程序正常工作，并且确切的文件是打开的。否则，connection.Open();将失败，并显示以下消息：

System.Data.OleDb.OleDbException occurred
  HResult=0x80004005
  Message=Neočekávaná chyba z externího ovladače databáze (1).
  Source=Microsoft JET Database Engine
  StackTrace:
   at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
   at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionInternal.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.OleDb.OleDbConnection.Open()
   at ExcelImport.GetDataTable(String excelFileName, String sqlSelect) in D:\__XXXX_webapp\WEBAPP\WEBAPP\App_Code\ExcelImport.cs:line 20
   at cz.company.mylogin.DataPump.DataPumpTheFileXLS() in D:\__XXXX_webapp\DataPump\Program.cs:line 249
   at cz.company.mylogin.DataPump.Main() in D:\__XXXX_webapp\DataPump\Program.cs:line 308

根据报告的HRESULT错误，我找到了相关原因https://support.microsoft.com/en-us/help/295297/prb-error-message-0x80004005-general-error-unable-to-open-registry-key

我不知道对HRESULT的解释是否具有误导性或是否真的是这个原因。

问题是：为什么在MS Excel中打开同一个文件时它会起作用？如何在不运行Excel的情况下获取数据还需要做什么？

Excel未运行时，Microsoft.Jet.OLEDB.4.0失败。怎么解决？

0 个答案: