专家坐堂-关于开流水账的问题Foxtable(狐表) - 新一代数据库软件，完美融合Access、Foxpro、Excel、vb.net之优势，人人都能掌握的快速软件开发工具!

Select Case e.DataCol.Name
    Case "产品","入库","出库"
        Dim drs As List(of DataRow)
        Dim Filter As String
        Filter = "[_SortKey] >= " & e.DataRow("_SortKey") & " And [产品] = \'" & e.DataRow("产品") & "\'"
        drs = e.DataTable.Select(Filter)
        For Each dr As DataRow In drs
            Filter = "[_SortKey] <= " & dr("_SortKey") & " And [产品] = \'" & dr("产品") & "\'"
            Dim Val1 As Double = e.DataTable.Compute("Sum(入库)",Filter)
            Dim Val2 As Double = e.DataTable.Compute("Sum(出库)",Filter)
            dr("库存") = Val1 - Val2
        Next
        If e.DataCol.Name = "产品" AndAlso e.OldValue IsNot Nothing AndAlso e.OldValue <> e.NewValue Then
            Filter = "[_SortKey] > " & e.DataRow("_SortKey") & " And [产品] = \'" & e.OldValue & "\'"
            drs = e.DataTable.Select(Filter)
            For Each dr As DataRow In drs
                Filter = "[_SortKey] <= " & dr("_SortKey") & " And [产品] = \'" & dr("产品") & "\'"
                Dim Val1 As Double = e.DataTable.Compute("Sum(入库)",Filter)
                Dim Val2 As Double = e.DataTable.Compute("Sum(出库)",Filter)
                dr("库存") = Val1 - Val2
            Next
        End If
End Select