ASP.NET 3.5: A Beginner's Guide - www.mustafaof.com

422ASP.NET 3.5: A Beginner’s GuideFigure 17-1 Sending a message back to the pagethe delay bumps as everything is hauled back and forth over the Internet. (Actually, it’sjust going to the Visual Studio 2008 server on your machine, so it’s not even subject toInternet traffic!)Ajax and ASP.NET 3.5ASP.NET 3.5 Ajax is easy to use and is efficient. Using Visual Studio 2008, you cancreate an Ajax web site using only two Ajax controls. The main Ajax control is what iscalled the UpdatePanel, where all of the elements in your Ajax application can be placed.The other control is the ScriptManager. The ScriptManager control is required to accessthe Ajax Library and partial page rendering without post-back.TIPThe property contains all of the content of an UpdatePanelcontrol. If you drag an UpdatePanel using Visual Studio 2008 into the editor andthen add a standard control inside the UpdatePanel from the Design mode, the property is added automatically. However, if you dothe same thing from the Source mode, no propertyis added automatically, and you have to add the tags by typing them. So, to get started in this next andsubsequent examples in this chapter, start off using the Design mode, and once youhave placed the Ajax and Standard controls inside the UpdatePanel, you can switchover to the Source mode if you wish.