News

Xamarin.Forms 4.2 Boosts Shell, But Devs Clamor for UWP Support

• By David Ramel
• 08/23/2019

Microsoft just shipped Xamarin.Forms 4.2 with enhanced Shell functionality to provide basic features required in iOS and Android apps, but many mobile developers are clamoring for Universal Windows Platform (UWP) support to be added.

Shell, which debuted in v4.0 in May, automatically provides fundamental features that most mobile applications require, thus reducing the complexity of mobile application development. These features include:

• A single place to describe the visual hierarchy of an application.
• A common navigation user experience.
• A URI-based navigation scheme that permits navigation to any page in the application.
• An integrated search handler.

In announcing the general availability of Xamarin.Forms 4.2 on Wednesday (Aug. 21), the dev team's Paul DiPietro noted enhancements to the popular feature. "Since its launch in Xamarin.Forms 4.0.0, Shell has been a huge hit with developers," DiPietro said. "Shell gives you a way to simplify their application structure and navigation from a streamlined API. Xamarin.Forms 4.2.0 introduces new APIs to give you more control over the lifecycle of the pages in your app. This includes some brand-new events implemented on the BaseShellItem for Appearing and Disappearing along with new methods for OnAppearing and OnDisappearing."

However, at the bottom of the post, several developers asked for UWP support also. Even though Microsoft's Windows Phone initiative has died as a mobile alternative to iOS and Android, UWP apps are still used on Windows 10 devices, such as tablets.

UWP support was requested in a March GitHub issue titled "Uwp Xamarin.Forms.Shell #5593" that stated: "Uwp Xamarin.Forms.Shell does not work correctly in uwp, the same way it works on android and ios." That issue has garnered 41 comments and spawned the pull request "Adds UWP support to Shell #6015."

Even though some developers are working on the issue, comments on DiPietro's blog post show it's still top-of-mind for several coders, who said things like:

• "Still waiting on Shell support on Windows. Sigh."
• "Yep it's the one thing stopping me from using Shell. And CollectionView. Shame as they both look great."
• "A statement from Microsoft, if and when Shell will be available for UWP would be helpful. Currently I cannot use Schell because a UWP version is required."
• "exactly!"
• "Shell for UWP + Xaml hot reload of xamarin forms pages in UWP"

Neither DiPietro nor anyone else from Microsoft responded to those comments. One thing DiPietro did mention in his post, though, was the delayed general availability debut of the new CollectionView that was originally intended for Xamarin.Forms 4.2.

"Our roadmap listed the new CollectionView for official release in Xamarin.Forms 4.2.0," he said. "Your feedback during the CollectionView Challenge was important in highlighting the features you need most. This included pull-to-refresh functionality, header/footer templates, and several others.

"Development has come a long way, but we want to make sure you have the best possible experience when using CollectionView. So at this time we are going to keep CollectionView under the Experimental flag in this release."

More information on Xamarin.Forms 4.2 is available in the release notes.