MSDN Magazine - January 2008 - (Page 27)

Accessing Data from a Mobile App John PAPA D ata access is an important aspect of developing applications with the Microsoft® .NET Compact Framework for Windows Mobile® devices. By using the existing architecture to send and receive data between your mobile application and your application server, you can pass data with either DataSets, custom objects, or scalar values. In this installment of DataPoints, I want to discuss best practices for data access strategies when developing mobile applications for Smartphones. I will demonstrate how to design a data-driven Smartphone application that can display and save data over the Internet. I will show you how to communicate with a server application that exposes methods to get data using a DataSet, custom objects, and a generic List of entities. Figure 1 Windows Mobile SDKs Target Device Smartphone Pocket PC Pocket PC Phone Required Windows Mobile 5.0 SDK Windows Mobile 5.0 SDK for Smartphone Windows Mobile 5.0 SDK for Pocket PC Windows Mobile 5.0 SDK for Pocket PC Required Windows Mobile 6 SDK Windows Mobile 6 Standard SDK Windows Mobile 6 Professional SDK Windows Mobile 6 Professional SDK Mobile Development To develop mobile applications, you must first install the .NET Compact Framework (and its latest service pack). The latest update is the .NET Compact Framework 2.0 with SP2. Before diving in, you must make some decisions about the platform (Windows Mobile 5.0 or Windows Mobile 6) and the device (or devices) you are going to target for your application. These decisions will affect Getting Started which SDKs you must install. I highly recommend testing on both the emulator and the deThe Windows Mobile 5.0 SDK is available in different versions, depending on whether you are targeting a Smartphone, a Pocket vice itself to avoid those situations when the application works PC, or a Pocket PC Phone. The Windows Mobile 6 SDK is also fine on the emulator but not on the device. My approach is to use available in different versions for different target platforms, but the the emulator throughout the process of developing a mobile apnaming conventions have changed and are now a bit less intuitive. plication, then deploy the application to a real mobile device at Figure 1 lists the various SDK versions and which devices they can certain checkpoints. Before debugging, make sure you run the Device Emulator from target. It goes without saying that if you want to target each type the Tools menu in Visual Studio®. Once you choose the emulator of device, you should install each of the SDKs. For this discussion, I am using Windows Mobile 5 for the Smart- you want, right-click on it and select Connect. The emulator will phone. The version is not critical, though, as the data-access con- then begin to boot the Smartphone. Once the Smartphone is running in the emulator, right-click the item in the Device Manager cepts presented remain the same regardless of version. again and select Cradle. Cradling allows After installing the .NET Compact the emulator to communicate with the Framework 2.0 with SP2 and the appronetwork. Finally, in Visual Studio, select priate Windows Mobile SDK, you must an emulator from the dropdown list in also install ActiveSync (for Windows® the Device toolbar (see Figure 2). XP) or Windows Mobile Device Center To get data, my sample application (for Windows Vista®). These are needcommunicates with a Web service on an ed for the mobile device emulator to IIS Web server. The Web service works communicate with your network or well for mobile applications, as it can the Internet. Figure 2 Selecting a Target Emulator january2008 27 You should also download and install an emulator that closely resembles the device you are targeting. For this column, I have opted for a landscape 320x240 screen. If your target devices have different screen sizes, you should test your app for each using all of the appropriate emulators. If you are using Windows Vista or the Windows Mobile 6 SDK, you need to install the Device Emulator 2.0. I know that this sounds like a lot of prerequisites to put in place, so I’ve included a list of links with this column in the download and on the MSDN Magazine Web site at msdn.microsoft.com/msdnmag/issues/08/01/datapoints. http://msdn.microsoft.com/msdnmag/issues/08/01/datapoints

Table of Contents Feed for the Digital Edition of MSDN Magazine - January 2008

MSDN Magazine - January 2008 Contents Toolbox CLR Inside Out Data Points Advanced Basics Cutting Edge IIS 7.0 - Enhance Your Apps with the Integrated ASP.NET Pipeline World Ready - Around the World with ASP.NET AJAX Applications WCF Syndication - HTTP Programming with WCF and the .NET Framework 3.5 Wicked Code Foundations Extreme ASP.NET {End Bracket}

MSDN Magazine - January 2008

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