DataGridView过滤功能

http://www.codeproject.com/Articles/33786/DataGridView-Filter-Popup

http://www.cnblogs.com/jaxu/archive/2011/08/04/2127365.html

http://www.360doc.com/content/12/1219/23/10939365_255194838.shtml

http://www.pin5i.com/showtopic-23492.html