问题：如何修改UpdateColumns()方法（如下）或OnTextChanged事件调用以仅使用触发事件的行？
现在，我正在通过UpdateColumns()使用事件调用方法来更新 GridView 单元格值，OnTextChanged如下所示：
<asp:TemplateField HeaderStyle-Width="35px">
<ItemTemplate>
<asp:TextBox OnTextChanged="UpdateColumns" ID="txtJan" CssClass="row"
runat="server" AutoPostBack="True" Text='<%# Eval("Jan","{0:#0}") %>'>
</asp:TextBox>
</ItemTemplate>
<HeaderTemplate>
Jan
</HeaderTemplate>
<FooterTemplate>
<asp:TextBox ID="txtJan" CssClass="row" runat="server"></asp:TextBox>
</FooterTemplate>
</asp:TemplateField>
下面是事件触发的UpdateColumns()方法。OnTextChanged它遍历表中的每一行并进行计算。我的 GridView 中有 15 列和 10 行，因此该操作需要大约 1 秒才能完成。如何修改我的方法以仅查看调用它的行？本质上，我只是想让操作执行得更快，而不是做无用的计算。
Protected Sub UpdateColumns(ByVal sender As Object, ByVal e As EventArgs)
Dim errors As New StringBuilder
Try
For Each row As GridViewRow In gvBuildingBlocks.Rows
_tjan = CType(row.FindControl("txtJan"), TextBox)
_tfeb = CType(row.FindControl("txtFeb"), TextBox)
_tmar = CType(row.FindControl("txtMar"), TextBox)
_tapr = CType(row.FindControl("txtApr"), TextBox)
_tmay = CType(row.FindControl("txtMay"), TextBox)
_tjun = CType(row.FindControl("txtJun"), TextBox)
_tjul = CType(row.FindControl("txtJul"), TextBox)
_taug = CType(row.FindControl("txtAug"), TextBox)
_tsep = CType(row.FindControl("txtSep"), TextBox)
_toct = CType(row.FindControl("txtOct"), TextBox)
_tnov = CType(row.FindControl("txtNov"), TextBox)
_tdec = CType(row.FindControl("txtDec"), TextBox)
_tq1 = CType(row.FindControl("txtQ1"), TextBox)
_tq2 = CType(row.FindControl("txtQ2"), TextBox)
_tq3 = CType(row.FindControl("txtQ3"), TextBox)
_tq4 = CType(row.FindControl("txtQ4"), TextBox)
_th1 = CType(row.FindControl("txtH1"), TextBox)
_th2 = CType(row.FindControl("txtH2"), TextBox)
_tt = CType(row.FindControl("txtYear"), TextBox)
If IsNumeric(_tjan.Text) And IsNumeric(_tfeb.Text) _
And IsNumeric(_tmar.Text) And IsNumeric(_tapr.Text) _
And IsNumeric(_tmay.Text) And IsNumeric(_tjun.Text) _
And IsNumeric(_tjul.Text) And IsNumeric(_taug.Text) _
And IsNumeric(_tsep.Text) And IsNumeric(_toct.Text) _
And IsNumeric(_tnov.Text) And IsNumeric(_tdec.Text) Then
_bbjan = Decimal.Parse(_tjan.Text)
_bbfeb = Decimal.Parse(_tfeb.Text)
_bbmar = Decimal.Parse(_tmar.Text)
_bbapr = Decimal.Parse(_tapr.Text)
_bbmay = Decimal.Parse(_tmay.Text)
_bbjun = Decimal.Parse(_tjun.Text)
_bbjul = Decimal.Parse(_tjul.Text)
_bbaug = Decimal.Parse(_taug.Text)
_bbsep = Decimal.Parse(_tsep.Text)
_bboct = Decimal.Parse(_toct.Text)
_bbnov = Decimal.Parse(_tnov.Text)
_bbdec = Decimal.Parse(_tdec.Text)
_bbq1 = _bbjan + _bbfeb + _bbmar
_bbq2 = _bbapr + _bbmay + _bbjun
_bbq3 = _bbjul + _bbaug + _bbsep
_bbq4 = _bboct + _bbnov + _bbdec
_bbh1 = _bbq1 + _bbq2
_bbh2 = _bbq3 + _bbq4
_bbtt = _bbh1 + _bbh2
_tq1.Text = _bbq1.ToString()
_tq2.Text = _bbq2.ToString()
_tq3.Text = _bbq3.ToString()
_tq4.Text = _bbq4.ToString()
_th1.Text = _bbh1.ToString()
_th2.Text = _bbh2.ToString()
_tt.Text = _bbtt.ToString()
_totalJan += _bbjan
_totalFeb += _bbfeb
_totalMar += _bbmar
_totalApr += _bbapr
_totalMay += _bbmay
_totalJun += _bbjun
_totalJul += _bbjul
_totalAug += _bbaug
_totalSep += _bbsep
_totalOct += _bboct
_totalNov += _bbnov
_totalDec += _bbdec
_totalQ1 += _bbq1
_totalQ2 += _bbq2
_totalQ3 += _bbq3
_totalQ4 += _bbq4
_totalH1 += _bbh1
_totalH2 += _bbh2
_totalT += _bbtt
Else
errors.Append("Error! Input string must be numeric. Please correct error(s).")
End If
Next
If errors.Length > 0 Then
'gvBuildingBlocks.DataSource = CType(Session("buildingBlocks"), DataTable)
'gvBuildingBlocks.DataBind()
ShowMessage(errors.ToString)
End If
_tjan = CType(gvBuildingBlocks.FooterRow.FindControl("txtJan"), TextBox)
_tfeb = CType(gvBuildingBlocks.FooterRow.FindControl("txtFeb"), TextBox)
_tmar = CType(gvBuildingBlocks.FooterRow.FindControl("txtMar"), TextBox)
_tapr = CType(gvBuildingBlocks.FooterRow.FindControl("txtApr"), TextBox)
_tmay = CType(gvBuildingBlocks.FooterRow.FindControl("txtMay"), TextBox)
_tjun = CType(gvBuildingBlocks.FooterRow.FindControl("txtJun"), TextBox)
_tjul = CType(gvBuildingBlocks.FooterRow.FindControl("txtJul"), TextBox)
_taug = CType(gvBuildingBlocks.FooterRow.FindControl("txtAug"), TextBox)
_tsep = CType(gvBuildingBlocks.FooterRow.FindControl("txtSep"), TextBox)
_toct = CType(gvBuildingBlocks.FooterRow.FindControl("txtOct"), TextBox)
_tnov = CType(gvBuildingBlocks.FooterRow.FindControl("txtNov"), TextBox)
_tdec = CType(gvBuildingBlocks.FooterRow.FindControl("txtDec"), TextBox)
_tq1 = CType(gvBuildingBlocks.FooterRow.FindControl("txtQ1"), TextBox)
_tq2 = CType(gvBuildingBlocks.FooterRow.FindControl("txtQ2"), TextBox)
_tq3 = CType(gvBuildingBlocks.FooterRow.FindControl("txtQ3"), TextBox)
_tq4 = CType(gvBuildingBlocks.FooterRow.FindControl("txtQ4"), TextBox)
_th1 = CType(gvBuildingBlocks.FooterRow.FindControl("txtH1"), TextBox)
_th2 = CType(gvBuildingBlocks.FooterRow.FindControl("txtH2"), TextBox)
_tt = CType(gvBuildingBlocks.FooterRow.FindControl("txtYear"), TextBox)
_tjan.Text = _totalJan.ToString()
_tfeb.Text = _totalFeb.ToString()
_tmar.Text = _totalMar.ToString()
_tapr.Text = _totalApr.ToString()
_tmay.Text = _totalMay.ToString()
_tjun.Text = _totalJun.ToString()
_tjul.Text = _totalJul.ToString()
_taug.Text = _totalAug.ToString()
_tsep.Text = _totalSep.ToString()
_toct.Text = _totalOct.ToString()
_tnov.Text = _totalNov.ToString()
_tdec.Text = _totalDec.ToString()
_tq1.Text = _totalQ1.ToString()
_tq2.Text = _totalQ2.ToString()
_tq3.Text = _totalQ3.ToString()
_tq4.Text = _totalQ4.ToString()
_th1.Text = _totalH1.ToString()
_th2.Text = _totalH2.ToString()
_tt.Text = _totalT.ToString()
Catch ex As Exception
ShowError("Exception: ", ex.ToString())
End Try
End Sub