主题：[求助]照着帮助写的代码报错

代码如下：

Dim dt As DataTable
Dim b As New GroupTableBuilder("统计表1",DataTables("经验教训"))
b.Groups.AddDef("编制日期",DateGroupEnum.Year,"年")
b.Groups.AddDef("编制日期",DateGroupEnum.Month,"月")
b.Groups.AddDef("问题分类")
b.Totals.AddDef("报告编号",AggregateEnum.Count,"记录数") '根据不重复值列来统计记录数,也就是记录数
dt = b.Build(False) '参数设置为False,生成一个临时表,不在主界面显示
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree(dt, "年|月|问题分类")
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("问题分类")
    Select Case nd.Level
        Case 0
            nd.Text = nd.text & "年(" & dt.Compute("Sum(记录数)","年 = " & Year) & "条)"
        Case 1
            nd.Text = nd.text & "月(" & dt.Compute("Sum(记录数)","年 = " & Year & " And 月 = " & Month) & "条)"
        Case 2
            nd.Text = nd.text & "(" & nd.DataRow("记录数") & "条)"
    End Select
Next
trv.Nodes.Insert("记录总数","记录总数: (" & dt.Compute("Sum(记录数)") & "条)",0)
trv.ResumeRedraw

错误如附件