主题：取得父节点编号以及节点路径全名

很简单，你删除totalcpno和FindFather两列的内容，然后在命令窗口执行下面的代码看看：

For Each dr1 As DataRow  In DataTables("data").Select("","sortkey")
    Dim idx As Integer = dr1("sortkey").LastIndexof("\")
    If idx < 0 Then
        dr1("totalcpno") = dr1("cpno")
        dr1("FindFather") = Nothing
    Else
        Dim pkey As String = dr1("sortkey").Substring(0,idx)
        dr1("FindFather") = pkey
        Dim dr2 As DataRow = DataTables("data").Find("sortkey = '" & pkey & "'")
        If dr2 IsNot Nothing
            dr1("totalcpno") = dr2("totalcpno") & "\" & dr1("cpno")
        Else
            dr1("totalcpno") = "输入错误"
        End If
    End If
Next

如果你要自动，在DatacolChanged事件设置代码：

Select Case e.DataCol.name
    Case "cpno","sortkey"
        Dim dr1 As DataRow = e.DataRow
        Dim idx As Integer = dr1("sortkey").LastIndexof("\")
        If idx < 0 Then
            dr1("totalcpno") = dr1("cpno")
            dr1("FindFather") = Nothing
        Else
            Dim pkey As String = dr1("sortkey").Substring(0,idx)
            dr1("FindFather") = pkey
            Dim dr2 As DataRow = DataTables("data").Find("sortkey = '" & pkey & "'")
            If dr2 IsNot Nothing
                dr1("totalcpno") = dr2("totalcpno") & "\" & dr1("cpno")
            Else
                dr1("totalcpno") = "输入错误"
            End If
        End If
End Select