主题：[求助]怎么有条件计算子表金额。

If e.DataCol.Name = "工程名称" Then
    Dim dr As DataRow = e.DataRow
    Dim dr1 As DataRow = DataTables("应交税金计算表").Find("工程名称 = '" & dr("工程名称") & "'")
    Dim dr2 As DataRow = DataTables("已交税金统计表").Find("工程名称 = '" & dr("工程名称") & "'")
    Dim nms() As String = {"企业所得税","营业税","城建税","教育费附加","地方教育费附加","防洪保安费","印花税"}
    If dr1 isnot Nothing AndAlso dr2 isnot Nothing Then
        For Each nm As String In nms
            If dr1(nm) <> dr2(nm) Then
                dr(nm) = dr1(nm) - dr2(nm)
            Else
                dr(nm) = Nothing
            End If
        Next
    End If
End If