public DataSet TransExcelToDataSet(string fileName, List<string> sheetNames)
    {
        OleDbConnection objConn =null;
        DataSet data =new DataSet();

        //创建读取excel连接
        string strConn ="Provider=Microsoft.Jet.OleDb.4.0;"+"data source="+ fileName
            +";Extended Properties='Excel 8.0;HDR=YES;IMEX=1'";
        try
        {

            objConn =new OleDbConnection(strConn);
            using (objConn)
            {
                OleDbDataAdapter sqlada =null;
                //遍历从配置文件中读取的sheet名称
                foreach (string sheetName in sheetNames)
                {
                    if (!string.IsNullOrEmpty(sheetName))
                    {
                        string strSql ="select \* From \["+ sheetName.Trim() +"$\]";
                        sqlada =new OleDbDataAdapter(strSql, objConn);
                        //填充dataset
                        sqlada.Fill(data, sheetName);
                    }
                }
            }
        }
        catch (Exception e)
        {
            thrownew Exception("将excel中指定sheet内容读入dataset出错！"+ e.Message +" strConn: "+ strConn +" ; fileName:"+ fileName);
            //throw e;
        }
        finally
        {
            if (objConn !=null)
            {
                objConn.Dispose();
                objConn.Close();
            }

            GC.Collect();
        }
        return data;
    }