How to develop apps for Win phone 7?

BANGALORE, INDIA: There are a ton of new mobile platforms out there iPhone, Android, Symbian and a few more. The first two have really taken off due to the availability of lots of apps in their respective App Stores. Microsoft's own mobile phone OS "Windows Mobile" has been stagnating for a while now, even though it had a great development platform. However, Microsoft has not really given up the race. Its upcoming Windows Phone 7 platform and the 'Metro' UI based on the Zune HD interface has been getting mostly rave reviews from whoever has played with the devices and software till now. Not only does it bring a completely new paradigm to the interface over the much-used icon based format, it also doubles up as a great development platform that can be used quite easily.

This article series will delve into the world of Windows Phone 7 (WP7, in short) development. We'll try to develop a real-world application over the coming months in this article that will explore all the different new features that are available in the platform. This part of the series starts off with an introduction to the platform itself and the setting up of the development environment.

Windows Phone 7 Development Platform
The Windows Phone 7 platform allows developers to create applications in two different ways:

Using Silverlight: This is the primary way that apps will be developed for WP7 and consists of the application written in ?Silverlight ? Microsoft's XAML based application development platform. The Silverlight available in WP7 is a special version built upon the Silverlight 3 with some phone specific additions made available. The developer will also get access to a large number of phone SDK calls that will let him perform some common tasks quite easily.

Using XNA: This is meant primarily for developers who are creating games for the WP7 platform. Not only will it allow more direct access to the graphics and sound hardware in the phone, it also has the ability to access the Games Hub (more about this a ?little later) and be able to synchronize the same game across the phone, PC and Xbox 360. In this series we will be looking only at the Silverlight apps development for the phone.

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Development Tools
Developing for WP7 is quite easy. The tools are currently in Beta state and freely available. The good thing is that even when the final release is done, it will also be made available completely for free. So you can start coding in the beta ?release secure in the knowledge that when the RTM hits, you can simply upgrade the install bits and it will start working. You can get the tools from http:// developer.windowsphone.com/. So what all does this have? Here's a list of what you get when you install the tools:

Visual Studio 2010 Express for Windows Phone: A special version of VS2010 for WP7 development

Expression Blend for Windows Phone: Another special version of Blend for WP7 UI designing

Windows Phone 7 Emulator: This is a full working image of an unlocked WP7 device that you can use to test and debug your apps till you get a real device

XNA Studio for Windows Phone: This is the XNA Game Development studio for WP7

Developer Registration Utility: Used to unlock your device for development

XAP Deployment Tool: For transferring XAP files directly to your phone

So, let's get started with a simple application first for this series. We'll starting looking into the different 'features' of the WP7 platform and how to develop for it in later parts. So go ahead and install the tools first.

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Your First WP7 App
To start off, open up Visual Studio 2010 Express for Windows Phone ? or if you already had a version of VS2010 installed, fire it up and go to the New Project window. Here select Visual C# | Silverlight for Windows Phone | Windows Phone Application. Give it a name like WP7HelloWorld and create it.

When the project is loaded, you will by default see the Windows Phone 7 designer on the left pane and the Silverlight XAML on the right. XAML and Silverlight is out of scope of this article but PCQuest has carried detailed articles on developing Silverlight applications earlier. You can also find a number of Silverlight tutorials on the Web.

For this sample, let's first do something very simple. Select the TextBlock that says 'MY APPLICATION'. You can change this over in the property window on the right to say 'MY FIRST WP7 APP'. Now select the 'page name' text block and find the TextBlock element in the XAML pane whose name is 'PageTitle'. Change the Text value to 'first page'. You will immediately see the changes reflect in the designer window. Now open the toolbox and drop in a TextBox, a button and a WebBrowser control. Change the first two controls' texts to ' and 'View'. Double click the button to enter its click event handler and enter the following code.

private void button1_Click(object sender, RoutedEventArgs e)
{
webBrowser1.Navigate(new
Uri(string.Format("http://twitter.com/{0}", textBox1.Text)));
}
Save both the files and press F5 to compile and debug the application. By default, the app will be deployed to the WP7 Emulator. So wait while the emulator boots up and the Silverlight .XAP file is deployed to the emulator. Once ready , the application is launched automatically. You can now start using it. For entering text into the textbox you can either use the on screen keyboard that automatically appears or press ?Pause/Break? on your keyboard and then simply type as you would normally. Press the 'View' button to load the Twitter account into the Web control. In a single line of code and 2 minutes of time, you've actually built a small Twitter client for WP7! Also remember that since this is running in 'Debug' mode in VS2010, you can use breakpoints, watches and all the other development tools built into VS to work with your application. You can also open the app in Blend to make its interface much more dynamic. But we'll take a look at all of this in the coming months.

For now, WP7 is still in the hands of only a few. But with the WP7 developer tools, you can get a taste of the platform as well as start developing applications for it right now so that a completely new market is available to your app as soon as the devices arrive by the end of this year.