XRTableCell of XRTable format change : string to datetime

OS : Windows 7
IDE : Microsoft Visual Studio Professional 2012
Microsoft .NET Framework 4.5.51209
DeploymentTool : DevExpress 14.1
Form : XtraReport

Date	Time
20150223	114322
20150211	212907
20150212	202059

I want to change column format string to datetime.
then, What should I do?

Ok, change cloumn's diplay format.
wasting my time...
Ok, reading devexpress doc.
wasting my time...
Ok, google serching.

I finally got it.
 

        private void xrTblCellDate_BeforePrint(object sender, System.Drawing.Printing.PrintEventArgs e)
        {
            var varDate = GetCurrentColumnValue((sender as XRTableCell).Tag.ToString());
            if (varDate != null && varDate.ToString() != "")
            {
                string strPattern = "yyyyMMdd";
                DateTime dtDate;
                if (DateTime.TryParseExact(varDate.ToString(), strPattern, null, System.Globalization.DateTimeStyles.None, out dtDate))
                    (sender as XRTableCell).Text = string.Format("{0:yyyy-MM-dd}", dtDate);
            }
        }

        private void xrTblCellTime_BeforePrint(object sender, System.Drawing.Printing.PrintEventArgs e)
        {
            var varTime = GetCurrentColumnValue((sender as XRTableCell).Tag.ToString());
            if (varTime != null && varTime.ToString() != "")
            {
                string strPattern = "hhmmss";
                TimeSpan dtTime;
                if (TimeSpan.TryParseExact(varTime.ToString(), strPattern, null, System.Globalization.TimeSpanStyles.None, out dtTime))
                    (sender as XRTableCell).Text = string.Format("{0}", dtTime);
            }
        }

Date	Time
2015-02-23	11:43:22
2015-02-11	21:29:07
2015-02-12	20:20:59