In what’s becoming a tradition, Microsoft has once again confused the version numbers of one of their key products. In brief what you need to target Windows Phone 7.5 is the Windows Phone 7.1 SDK and the August 2011 build of the Windows Phone Toolkit. Or you can give the PhoneGap beta a spin.
“Windows Phone 7.5” is the official name for the successor to Windows Phone 7. Originally called “Mango” or “Windows Phone 7.1”, it WP 7.5 is packed with features deemed necessary to compete with the iOS and Android-based devices. From a technological standpoint it seems to be a solid operating system with support for both Silverlight 4 and IE 9‘s variant of HTML 5. Native development is not possible at this time, that level of the operating system is essentially restricted to device drivers. Rumor has it that Adobe and possibly the actual device manufacturers have access to a native SDK, but nothing definitive is known at this time.
.NET Development
The preferred development environment for Windows Phone 7.5 is Silverlight 4. In the previous version developers had to choose between Silverlight 3 or XNA, but that dichotomy is no longer exists. Though the final version won’t be ready until September, developers can now use the release candidate of the matching SDK, confusingly named Windows Phone SDK 7.1.
Like the browser-based version of Silverlight, Microsoft has a separate project for experimental features. The full name of this is the Windows Phone Toolkit - August 2011 (7.1 SDK). Jeff Wilcox is highlighting these new features for this release.
- LongListSelector has been rebuilt and redesigned to take advantage of the new smooth scrolling and off-thread touch input support in ‘Mango’. This is a buttery-smooth control for showing lists, including grouping and jump list support.
- MultiselectList control enables multiple selection for easily working with lists of data, similar to the Mail app’s capability.
- LockablePivot adds a special mode to the Pivot control where only the current item is shown (often used with multiple selection).
- ExpanderView is a primitive items control that can be used for expanding and collapsing items (like the threaded views in the Mail app).
- HubTile lets you add beautiful, informative, animated tiles to your application, similar to the new People groups in ‘Mango’.
- ContextMenu control has been reworked: performance improvements and visual consistency fixes.
- ListPicker now supports multiple selection.
- RecurringDaysPicker lets your users select a day of the week.
- Date & Time Converters localized to 22 languages. The converters let developers easily display date and time in the user interface in one of the many styles found throughout the phone’s UI, from a short date like ‘7/19’ to relative times like ‘about a month ago’.
- Page Transitions have improved performance for a more responsive feel.
- PhoneTextBox is an early look at an enhanced text box with action icon support, watermarking, etc.
The toolkit is available as an open source project under the Microsoft Public License.
Web Development
The web browser included in WP 7.5 is Internet Explorer 9, which in theory means anything that works in IE 9 for the desktop will also work in the phone’s browser. There are numerous compatibility charts, one of the more useful one is found on CanIUse.com.
Native Feature Support with HTML/JavaScript Development
PhoneGap offers a way to access native features on the phone while still using HTML and JavaScript in a cross-platform setting. The PhoneGap runtime is essentially a dedicated web browser that is backed with the application it runs. AJAX calls to specially formed URLs are intercepted by this “browser” and rerouted to native calls on the device. Applications built this way need to be repackaged for each target operating system. Full support is offered for Android and newer iOS devices, with many other devices having partial support.
Matt Lacey is leading the effort to offer PhoneGap support for Windows Phone 7.5. It currently isn’t release quality, but for internal applications and demos it may be enough. There is also an ongoing project for PhoneGap on Blackberry.
Adobe Flash/AIR
Unfortunately it has been over a year since we heard anything definitive from Adobe. At this point our recommendation is to not bet on AIR to actually be available this year, but we cannot rule out a surprise announcement at the BUILD conference either.