We are having some issues with a drop down list when it is populated with a large amount of items (1800).
We have the drop down list containing vendors sitting on a master page and a couple of telerik RadHtmlCharts on a child page that show the sales for the selected vendor. On first load there is a default selected vendor and the graphs display that vendor's sales. The user can then change the vendor in the drop down list and the graphs will change to show that vendor's sales. Pretty basic stuff.
When the page is first loaded it renders quickly and without issue, but if the user changes the selected vendor the page takes a good 15 seconds to load. It loads partially, but then takes extra time to load the charts. The browser locks up while it's doing it. In some cases it will crash the browser.
We have tried replacing the drop down list with a rad combo box and the issue remains. If we change the rad drop down list to the standard ASP.NET drop down list the issue goes away.
The issue only seem to occur in Chrome. In Firefox the page loads quickly.
Attached is the Timeline from Chrome dev tools. I'm wondering if this is an issue with Layout and Recalculate Style? This happens a lot when the user changes the selected vendor, but you don't see it happening when the page first loads.
The data for the drop down list is loaded during Page_Load like so:
DataTable dtVendors = dbMain.get_VendorList_by_AccountID_ForMenu((
(dtVendors.Rows.Count > 0)
(dtVendors.Rows.Count > 1)
rddlVendors.DataSource = dtVendors;
rddlVendors.SelectedValue = Session[
Let me know if you require any more information.