请教老师，下面代码是写在Afteropenproject, 但是没有在“个人主表.个人副表”的因子名称列生成下拉目录树，也没有小三角下拉标志，是否还要在对应的TABLE表属性中写什么代码？

Dim cmd As New SQLCommand
Dim dt As DataTable
cmd.C onnectionName =
cmd.C ommandText = "SELECT DISTINCT 因子专业,因子名称 F  rom {因子库主表}"
dt = cmd.ExecuteReader()
\'生成目录树
Dim tb As New DropTreeBuilder
tb.SourceTable = dt
tb.TreeCols = "因子专业|因子名称"
tb.SourceCols = "因子专业|因子名称"
tb.ReceiveCols = "因子专业|因子名称"
Tables("个人主表.个人副表").Cols("因子名称").DropTree = tb.Build()