主题：[求助]循环次数太多，怎么处理？

    For Each danwei As String In danwei_list

        For Each bubie As String In DataTables("成绩库").GetValues("部别", "")

            If e.Form.Controls("年级").value Is Nothing Then

                MessageBox.Show("请选择或输入统计年级后再执行此操作","中止操作",MessageBoxButtons.YesNo, MessageBoxIcon.Question)

            Else

                Functions.Execute("筛选记录",dt)

                Dim nianji As String = e.Form.Controls("年级").text

                For Each ban As String In DataTables("成绩库").GetValues("班","[单位]= '" & danwei & "'And [年级]= '" & nianji & "'And [部别]= '" & bubie  & "'")

                    zdr = DataTables(  Km & "分数段" ).datarows.addnew()

                    zdr("单位") = danwei

                    zdr("部别") = bubie

                    zdr("年级") = nianji

                    zdr("班") = ban

                Next

            End If

        Next

    Next