直接用find方法。如
Dim fdr As DataRow = DataTables("价格").Find("阶梯 = 'Y' and 产品 = 'B' and _Identify < " & e.datarow("_Identify"), "_Identify desc")
msgbox(fdr("最大值"))
http://www.foxtable.com/webhelp/scr/2237.htm