主题：[求助]目录树格式表达式

Dim cmd As New SQLCommand
Dim dt As DataTable
cmd.CommandText = "Select Distinct Year(日期) As 年, Month(日期) As 月, 产品 F rom {订单}"
dt = cmd.ExecuteReader()
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree(dt, "年|月|产品")
trv.Nodes.Insert("显示所有行",0)