主题：删除行提示

http://www.foxtable.com/help/topics/0632.htm

=和like对于null无效。

你应该逐列合成表达式：

Dim nms() As String = {"一级类别","二级类别","三级类别","四级类别","五级类别","六级类别"}
Dim flt As String
Dim dr As DataRow  = e.DataRow
For Each nm As String In nms
    If flt > "" Then
        flt = flt & " And "
    End If
   If dr.IsNull(nm) Then
        flt = flt & nm & " Is Null"
    Else
       flt = flt & nm & "= '" & dr(nm) & "'"
   End If
Next
If e.DataTable.Select(flt).Count = 1 Then

End If