<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<asp:UpdateProgress ID="UpdateProgress1" runat="server" AssociatedUpdatePanelID="UpdatePanel1" DisplayAfter="0">
<!--- your content here --->
background: url(/images/ajax-loader.gif) top left no-repeat;
by John Avis | February 20, 2019
I was recently doing some work on a website which has a mixture of older Classic ASP pages and ASP.NET Web Forms pages and ran into problems with custom error pages.
by John Avis | July 6, 2017
There are a few methods for hiding and showing Bootstrap 3.x and 4.x modals in an ASP.NET Web Forms application. This technique is pure ASP.NET (requires no client script) and allows you to show and hide modals by changing the Visible property of a containing PlaceHolder or Panel.
by John Avis | April 12, 2017
If you have an ASP.NET Web Forms page with multiple UpdatePanels and multiple UpdateProgress controls, sometimes you may want one or more UpdateProgress controls associated with a specific UpdatePanel, and one or more UpdateProgress controls that have no association with an UpdatePanel so are shown when any UpdatePanel is updated.