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A Solution for the Wireless Muddle
ASP.NET Mobile Controls provide a solution for the "wireless muddle" that caused so many problems for the developer in the preceding scenario. Wireless developers have to cope with a confusing variety of different devices—small or large devices with different-size screens, in color or monochrome, and that require one of the HTML, cHTML, WML, or XHTML markup languages, and quite often a specific "dialect" of one of those. Since the first edition of this book came out early in 2002, the situation has gotten more confusing! At that time, WAP/WML 1.1 browsers were commonplace in Europe, cHTML 1.0 browsers were predominant in Japan, and Pocket PCs and Palm devices using an HTML 3.2 browser were the favored handheld devices for businesses. A year later, you can walk into a shop of any of the major mobile network operators and be faced with mobile phones with WML 1.1 or WML 1.3 browsers, Pocket PC Phone Edition and Microsoft Smartphone devices with HTML browsers, and smartphones with WAP 2.0 browsers that require XHTML Mobile Profile (XHTML-MP) markup, which is the successor to WML. Japanese i-mode technology, already a huge success in Japan, is now being offered by operators in Europe and North America. PDAs and higher-end Smartphones usually have HTML 3.2 browsers, although the version of Pocket Internet Explorer included in the latest release of Microsoft's operating system for handheld devices, Microsoft Windows CE .NET, accepts HTML 4.0 markup.How then do you create an application that works with a significant number of these devices? If you're lucky and you can control which devices are issued to your users, you can standardize on one device and one technology. Few of us will have that luxury, however. Even if you build an application for one specific device, the speed of technological change in this industry means that you will quite likely be looking at a major rewrite a year down the line, when you want to take advantage of a new generation of handheld devices.The answer is to make the technology on the client device an irrelevance—or to put it another way, to use middleware on the Web server that takes care of worrying about the specific requirements of a particular client device on your behalf. You develop a single application using ASP.NET Mobile Controls, deploy it to a Windows Web server running Internet Information Services (IIS) and the Microsoft .NET Framework, and that application works with over 200 different kinds of mobile devices from many different vendors, each with its own specific requirements of markup language and screen size, as illustrated in Figure 1-2. Microsoft regularly releases Device Update packs for ASP.NET Mobile Controls that add support for still more handheld devices.
Figure 1-2: The ASP.NET Mobile Controls use adaptive rendering to support over 200 different handheld devices from a single application.
