主题：请大神指教 计算优化

If DataTables("统计").HasChanges Then
    'DataTables("统计").save
End If

e.Form.Controls("Label1").Text = " 更新完毕."

e.Form.Controls("Label1").Text = "正在处理数据..."
Application.DoEvents()

Dim drs = DataTables("sum").Select("日期时间 <= #" & Date.Today.AddDays(1) & "# and 日期时间 > #" & Date.Today & "#  ", "物料编码,日期时间")
Dim p As WinForm.ProgressBar
p = e.Form.Controls("ProgressBar1")
p.Maximum = drs.Count  '设置最大值
p.Minimum = 0 '设置最小值
p.Value = 0 '设置当前值

DataTables("统计").ResumeRedraw
DataTables("统计").StopRedraw
Dim st As Date = Date.Now '将开始时间保存在变量st中
Dim pdr As DataRow = Nothing
Dim sum As Double = 0

For Each dr As DataRow In drs
    Dim dr1 As DataRow = DataTables("统计").AddNew()
   
    dr1("物料编码") = dr("物料编码")
    dr1("日期时间") = dr("日期时间")
   
    If pdr Is Nothing OrElse dr1("物料编码") <> pdr("物料编码") Then
        sum = 0
        For Each dr2 As DataRow In DataTables("sum").Select(" 物料编码= '" & dr("物料编码") & "' ","日期时间")
            If dr2("日期时间") <= dr1("日期时间") Then
                sum += dr2("需求数量")
            Else
                Exit For
            End If
        Next
    Else
        sum = pdr("在此之前的需求数量") + dr("需求数量")
    End If
    dr1("在此之前的需求数量") = sum
    pdr = dr1
    p.Value += 1 '当前值为已经完成的行数
    e.Form.Controls("Label1").Text = "..." & p.Value
    Application.DoEvents()
Next

DataTables("统计").ResumeRedraw

If DataTables("统计").HasChanges Then
    'DataTables("统计").save
End If

e.Form.Controls("Label1").Text = " 更新完毕."