1、窗口的AfterLoad事件代码改为：

Dim cmd As New S
Dim dt As DataTable
cmd.CommandText = "SEL  ECT DIST  INCT Year(日期) As 年, Month(日期) As 月, 产品 From {订单}"
dt = cmd.ExecuteReader()
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree(dt, "年|月|产品")

2、目录树的NodeMouseDoubleClick事件代码改为：

Dim dr As DataRow = e.Node.DataRow \'获取生成此节点的行
Dim Filter As String
Dim Year As Integer = dr("年")
Dim Month As Integer = dr("月")
Dim Product As String = dr("产品")
Select Case e.Node.Level
    Case 0
        Filter ="Year(日期) = " & Year
    Case 1
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month
    Case 2
        Filter ="Year(日期) = " & Year & " And Month(日期) = " & Month & " And 产品 = \'" & Product & "\'"
End Select
DataTables("订单").LoadFilter = Filter
DataTables("订单").Load()

以上是实现  年|月|产品的加载树。

如何实现，   年|月|周