主题：[求助]关于计算的问题

下拉窗口

If e.Selected Then '如果选择了值
    Dim tbl As Table = Tables("窗口3_Table1")
    If tbl.Current IsNot Nothing Then
        Dim idx As String = e.Form.DropDownBox.BindingField.Split(".")(1).replace("收费项目", "")
        Tables("处方").Current("收费项目" & idx) = tbl.Current("收费项目")
        Tables("处方").Current("项目规格" & idx) = tbl.Current("项目规格")
        Tables("处方").Current("单价" & idx) = tbl.Current("单价")
    End If
End If

datacolchanged事件

Dim dr As DataRow = e.DataRow
Select Case e.DataCol.Name
    Case "剂量1","单价1","单价2","剂量2","单价3","剂量3" ,"单价4","剂量4" ,"单价5","剂量5" ,"注射费"
       
        dr("药费") = dr("剂量1") * dr("单价1") + dr("剂量2") * dr("单价2") + dr("剂量3") * dr("单价3") + dr("剂量4") * dr("单价4") + dr("剂量5") * dr("单价5")
        dr("合计") = dr("剂量1") * dr("单价1") + dr("剂量2") * dr("单价2") + dr("剂量3") * dr("单价3") + dr("剂量4") * dr("单价4") + dr("剂量5") * dr("单价5") + dr("注射费")
    Case "收费项目1","收费项目2","收费项目3","收费项目4","收费项目5"
        Dim idx As String = right(e.DataCol.Name,1)
        If e.NewValue = Nothing
            e.DataRow("项目规格" & idx) = Nothing
            e.DataRow("单价" & idx) = Nothing
        Else
            Dim fdr As DataRow = DataTables("药品清单模板").find("收费项目 = '" & e.DataRow(e.DataCol.Name) & "'")
            If fdr IsNot Nothing Then
                e.DataRow("项目规格" & idx) = fdr("项目规格")
                e.DataRow("单价" & idx) = fdr("单价")
            Else
                e.DataRow("项目规格" & idx) = Nothing
                e.DataRow("单价" & idx) = Nothing
            End If
        End If
End Select