参考：

http://www.foxtable.com/help/topics/0151.htm

自定义函数

Addtree1

Dim nd As WinForm.TreeNode = args(0)

Dim dt As DataTable = args(1)

Dim drs As  List(of DataRow)

drs = dt.Select("[上级代码] = \'" & nd.name & "\'","功能分类_代码")

For Each dr As DataRow In drs

    Dim cd As Winform.TreeNode = nd.Nodes.Add(dr("功能分类_代码"),dr("功能分类_代码") &":"& dr("功能分类_科目名称"))

    Functions.Execute("Addtree1",cd,dt)

Next

功能分类窗口_AfterLoad

Dim tr As WinForm.TreeView = e.Form.Controls("TreeView1")

Dim nd As WinForm.TreeNode

Dim dt As DataTable = DataTables("功能分类")

tr.StopRedraw()

tr.Nodes.Clear

nd =tr.Nodes.Add("1","显示全部")

For Each dr As DataRow In dt.Select("","功能分类_代码")    \'按功能分类代码排序

    If dr.IsNull("上级代码") Then

        nd = tr.Nodes.Add(dr("功能分类_代码"),dr("功能分类_代码") & ":" & dr("功能分类_科目名称"))

        Functions.Execute("Addtree1",nd,dt)

    End If

Next

tr.ResumeRedraw()

复制二段重要代码  自己去看一下就明了