打开项目加载treeview出现“未将对象引用设置到对象的实例” - 专家坐堂 - Foxtable(狐表) - 新一代数据库软件，完美融合Access、Foxpro、Excel、vb.net之优势，人人都能掌握的快速软件开发工具!

把treeview的代码写进窗口的afterload里

应用窗口不会报错

但是重新打开项目，就出现了

"未将对象引用设置到对象的实例”

需要另外设置一个加载的按钮才行。

Dim dt As DataTable

Dim b As New GroupTableBuilder("统计表1",DataTables("RMT收据"))

b.Groups.AddDef("da",DateGroupEnum.Year,"年")

b.Groups.AddDef("da",DateGroupEnum.Month,"月")

b.Groups.AddDef("da",DateGroupEnum.Day,"日")

b.Totals.AddDef("hr",AggregateEnum.Sum,"hour") '根据客户列来统计记录数,也就是订单数

dt = b.Build(True) '参数设置为True,生成一个临时表,不在主界面显示

'然后根据统计表生成目录树

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

trv.BuildTree(dt, "年|月|日")

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 Day As Integer = nd.DataRow("日")

Select Case nd.Level

Case 0

nd.Text = nd.text & "年(" & dt.Compute("Sum(hour)","年 = " & Year) & "hr)"

Case 1

nd.Text = nd.text & "月(" & dt.Compute("Sum(hour)","年 = " & Year & " And 月 = " & Month) & "hr)"

Case 2

nd.Text = nd.text & "日(" & dt.Compute("Sum(hour)","年 = " & Year & " And 月 = " & Month & " And 日 = " & Day) & "hr)"

End Select

trv.Nodes.Insert("显示所有行","显示所有行",0)

trv.ResumeRedraw

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