Summary

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Firewall feature. If you still cannot connect to the emulator for testing, try the usual new-technology problem-solving tactics: Search Google Groups or MSDN, post a message on .NET user groups, or throw up your hands.

This chapter begins by exploring the limitations you'll face when writing programs for mobile devices—primarily PDAs and cell phones today, but who knows what tomorrow has to offer? The .NET Compact Framework is a condensed, stripped-down version of the familiar .NET Framework you're used to. You'll face memory and processor speed restrictions that you don't face when writing VB.NET applications for full-size desktops and portables.

But the most severe challenge is I/O. The keyboard on portable devices (if any) is pretty difficult to type on (so you'll want to help your users by avoiding typed input whenever possible). And the screen is very, very small. It may not even have color. How do you handle the screen compatibility problem? Programs are designed differently for black and white screens versus color.

You also saw that quite a few control properties aren't available in the Compact .NET Framework. Microsoft isn't, however, blind to these problems. For one thing, they've designed libraries specific to individual brands, and even individual models of mobile devices.

The solutions to the connectivity problem (should the connection persist throughout the session?) and security issues were discussed. Then you saw how to use the built-in mobile device simulator, how to navigate between forms, and some new features on the Toolbox when you're working with the .NET IDE within the template that Microsoft has named the ASP.NET Mobile Web Application.

You saw how to write source code for a mobile application, how to display lists in various ways, how to employ tracing during debugging, how to intercept error messages and replace them with your own, user-friendly versions, and how to use emulators so you don't have to go to the trouble of connecting to an actual mobile device during program development.

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