How to set the gridview column as this format?

Hi, I want to set my gridview column as this format:

All I need is: If I have: 1334.234, 34566.1, 453443.0666, 3254

I want to show as: 1,334.23 ; 34,566.10  ; 453,443.07 ; 3,254.00 (see the separator "," and 2 decimals)

I have tried this: DataFormatString="{0:n}" HtmlEncode="False", but it does not work . any other format patten to achieve my request?

BTW, I am using VS2012, web form gridview.

Thanks a lot,