用连接数据库的方式读取excel

之前喜欢用 hssfworkbook直接将excel读取到workbook中，这样直接对sheet进行解析。可是当数据量很大，数据文件到5M以后c#的内存占用很大，就会很卡了。所以改用这种方法读取到dataset中，再对数据进行解析。直接上代码：

public static DataSet GetExcelTableByOleDB(string strExcelPath)
        {
            try
            {
                DataTable dtExcel = new DataTable();
                string strExtension = Path.GetExtension(strExcelPath);
                OleDbConnection objConn = null;
                switch (strExtension)
                {
                    case ".xls":
                        objConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strExcelPath + ";" + "Extended Properties=\"Excel 8.0;HDR=NO;IMEX=1;\"");
                        break;
                    case ".xlsx":
                        objConn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strExcelPath + ";" + "Extended Properties=\"Excel 12.0;HDR=NO;IMEX=1;\"");
                        break;
                    default:
                        objConn = null;
                        break;
                }
                if (objConn == null)
                {
                    return null;
                }
                objConn.Open();
                DataTable sheetNames = objConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                DataSet ds = new DataSet();
                if (sheetNames == null)
                    return null;
                foreach (DataRow dr in sheetNames.Rows)
                {
                    string strSql = "select * from [" + dr[2] + "]";
                    OleDbDataAdapter myData = new OleDbDataAdapter(strSql, objConn);
                    myData.Fill(ds, dr[2].ToString());
                }
                objConn.Close();
                return ds;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }