类似
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree(dt, "产品|年|月")
trv.StopRedraw
For Each nd As WinForm.TreeNode In trv.AllNodes
Dim Year As Integer = nd.DataRow("年")
Dim Month As Integer = nd.DataRow("月")
Dim Product As String = nd.DataRow("产品")
Select Case nd.Level
Case 1
nd.Text = nd.text & "年(" & dt.Compute("Sum(订单数)","年 = " & Year & " and 产品 = '" & Product & "'") & "条)"
Case 2
nd.Text = nd.text & "月(" & dt.Compute("Sum(订单数)","年 = " & Year & " And 月 = " & Month & " and 产品 = '" & Product & "'") & "条)"
Case 0
nd.Text = nd.text & "(" & nd.DataRow("订单数") & ")"
End Select
Next
trv.Nodes.Insert("加载所有行","加载所有行(" & dt.Compute("Sum(订单数)") & "条)",0)
trv.ResumeRedraw