Dim dr As DataRow = e.DataRow
If e.DataCol.Name = "开始日期" orelse e.DataCol.Name = "截止日期"
if dr.IsNull("开始日期") = False andalso dr.IsNull("截止日期") = False andalso dr.IsNull("编号") = False Then
dr("月数") = DataTables("登记表").Compute("count(月份)","编号 = '" & dr("编号") & "' And [开始日期] = '" & dr("开始日期") & "' And [截止日期] = '" & dr("截止日期") & "'")
else
dr("月数") = nothing
endif
End If