在页面加载时，将您的Querystring值存储到HiddenFieldValue中，并使用该值继续进行操作.

一些代码将有助于理解您的关注.

On page load store your Querystring value into an HiddenFieldValue and use this value to proceed further.

Some code would be beneficial to understand ur concern.

有关我的问题的一些代码:
我在表格中创建了一个链接以打开弹出窗口:AddCell(A href = javascript:ShowModalDialog()，reservationDetailsId = + reserDetail.ReservationDetailsId + Visitor</A，tr);
在旁边的链接中，在ReservationDetailId参数中传递数据，并在弹出窗口中加载它
尝试过此方法但不起作用:
if(Request.QueryString [& quot; reservationDetailsId& quot;]！= null)
{
Label7.Text = Request.QueryString [& quot; reservationDetailsId& quot;].ToString();
}
无法将qwerystring值存储到HiddenFieldvalue中，因为加载弹出窗口不适用于Request.QweryString.

some code about my question:
I make a link in table for open my popup: AddCell(A href=javascript:ShowModalDialog(),reservationDetailsId= + reserDetail.ReservationDetailsId + Visitor&lt;/A, tr);
in side a link a pass data in reservationDetailId parameter and get it in popup load
tried this but doesn''t work:
if (Request.QueryString[&quot;reservationDetailsId&quot;] != null)
{
Label7.Text = Request.QueryString[&quot;reservationDetailsId&quot;].ToString();
}
to store a qwerystring value into HiddenFieldvalue is not possible because is load popup which is not work with Request.QweryString.