The ASP.NET AJAX UpdatePanel provides a quick and easy way to implement a snappier, AJAX-based user interface in an ASP.NET WebForm. In a nutshell, UpdatePanels allow page developers to refresh selected parts of the page (instead of refreshing the entire page). Typically, an UpdatePanel contains user interface elements that would normally trigger a full page postback–controls like Buttons or DropDownLists that have their AutoPostBack property set to True. Such controls, when placed inside an UpdatePanel, cause a partial page postback to occur. On a partial page postback only the contents of the UpdatePanel are refreshed, avoiding the “flash” of having the entire page reloaded.(For a more in-depth look at the UpdatePanel control, refer back to the Using the UpdatePanel installment in this article series.)
the UpdatePanel. Unfortunately, no such function exists. Instead, you have to write script that triggers a partial page postback for the UpdatePanel you want to refresh. This article looks at how to accomplish this using just a single line of markup/script and includes a working demo you can download and try out for yourself. Click here to read more!