主题：请教狐狸爸爸，开发中遇到菜鸟级问题了（问题已解决）

Dim md As New SQLCommand
Dim dp As DataTable
md.CommandText = "SELECT DISTINCT 咨询作业_作业日期,咨询项目_委托人,咨询项目_一级名称 From {咨询项目登记表}"
dp = md.ExecuteReader()
Dim tv As WinForm.TreeView = e.Form.Controls("TreeView3")
tv.BuildTree(dp,"","咨询作业_作业日期","咨询项目_委托人","咨询项目_一级名称")
tv.Nodes.Insert("加载全部数据",0)

Dim Filter As String
If e.Node.Text = "加载所有数据" Then
    Filter = ""
Else
    Dim Value() As String
    Value = e.Node.FullPath.Split("\")
    Select Case e.Node.Level
        Case 0
            Filter ="[咨询作业_作业日期] = '" & Value(0) & "'"
        Case 1
            Filter ="[咨询作业_作业日期] = '" & Value(0) & "' And [咨询项目_一级名称] = '" & Value(1) & "'"
        Case 2
            Filter ="[咨询作业_作业日期] = '" & Value(0) & "' And [咨询项目_一级名称] = '" & Value(1) & "' And [咨询项目_委托人] = '" & Value(2) & "'"
    End Select
End If
DataTables("咨询项目登记表").LoadFilter = Filter
DataTables("咨询项目登记表").Load()