主题：求一种提取的解决方案

可以了，谢谢红袍老师，其实只是我没有寻求到导入显示BOM的好方法，才有这么个奇怪的想法，真的非常谢谢了

红色代码注释掉

Select Case e.DataCol.name
    Case "二级编码","初始数据"
        If e.DataRow.IsNull("二级编码") = False Then
            Dim drs As List(Of DataRow) = DataTables("BOM").Select("子件 = '" & e.DataRow("二级编码") & "'")
            If drs.count = 0 Then
                e.DataRow("库存数量") = e.DataRow("初始数据") + DataTables("商品入库").Compute("sum(入库数量)", "二级编码 = '" &e.DataRow("二级编码") & "'") - DataTables("商品出库").Compute("sum(商品数量)", "二级编码 = '" &e.DataRow("二级编码") & "'")
            Else
                Dim sum As Double = 0
                For Each dr As DataRow In drs
                    sum += DataTables("商品出库").Compute("sum(商品数量)", "二级编码 = '" & dr("二级编码") & "'") * dr("系数")
                Next
                'sum += DataTables("商品出库").Compute("sum(商品数量)", "二级编码 = '" &e.DataRow("二级编码") & "'")
                e.DataRow("库存数量") = e.DataRow("初始数据") + DataTables("商品入库").Compute("sum(入库数量)", "二级编码 = '" &e.DataRow("二级编码") & "'") - sum
            End If
        Else
            e.DataRow("库存数量") = e.DataRow("初始数据")
        End If
End Select