主题：会计科目，一般不用3开头的科目；怎么处理？应该怎么写好？

我测试没问题，请用实例说明。

Dim tr As WinForm.TreeView = e.Form.Controls("TreeView1")
Dim rts() As String = {"全部","资产","负债", "权益", "成本","损益"}
Dim nd As WinForm.TreeNode
Dim dt As DataTable = DataTables("会计科目")
tr.StopRedraw()
tr.Nodes.Clear
For Each rt As String In rts
    tr.Nodes.Add(rt)
Next
For Each dr As DataRow In dt.Select("", "科目代码")
    If dr.IsNull("科目代码") = False AndAlso dr("科目代码").Length = 4 Then
        Dim i As Integer = CInt(dr("科目代码").Substring(0,1))
        If i <> 3 Then
            nd = tr.Nodes(i).Nodes.Add(dr("科目代码"),dr("科目代码") & " " & dr("科目名称"))
            Functions.Execute("AddChildren",nd,dt)
        End If
    End If
Next
tr.Nodes(3).Delete
tr.ResumeRedraw()