Hello Folks,

I have spoken with the dev team and have some good news for you. The team is actually in the middle of working on this right now and are planning to have it in the next minor release.

You should be following the Provide Support for AndroidX Feature Request, that is where you will be alerted when the new release is available (this thread was for XF 4.5 support which was completed in R1 2020)

As I alluded to at the end of my last reply, you can target 29 but still have AndroidX and Xamarin.Android Support libraries, but this is not recommended. Instead, my guidance would be to keep developing as you are now (with 28 targeted). Then, when we release the updated assemblies, you can safely switch the target SDK to API 29 and migrate to AndroidX.

Regards,
Lance | Manager - Technical Support
Progress Telerik

Hi Francis and Marc,

Thank you for sharing, I have forwarded the article to the UI for Xamarin team. Either I, or someone from the team, will reply back to this thread once they've reviewed the situation.

In the meantime, to recap the issue, I believe it was only a problem with the AndroidX libraries, not that actual target SDK. In theory, I think you should be able to target 29, but keep using Xamarin.Android Support Library NuGet packages (instead of migrating to AndroidX libraries). However, I do not have solid proof on this yet and will need the dev team to weigh in.

Thank you for your patience while we work on making sure you will be able to publish by 8/3 (or update by 11/2).

Regards,
Lance | Manager - Technical Support
Progress Telerik

Hi Folks,

In the 2020.1.318 release (release notes), we implemented a change that will prevent an exception that was caused by a method missing in AndroidX.  This means you can now use Xamarin.Forms 4.5 for all the projects in the solution.

Target Android SDK Note

Although you can use XF 4.5, at this time we discourage targeting API 29. In your Android project setting, check the following values are set to Android 9 (API 28)

You can also use my attached project as a reference.

Regards,
Lance | Team Lead - US DevTools Support
Progress Telerik

Hello Marc,

Thank you for clarifying, that is indeed an important distinction. Just so that it's extra clear for anyone visiting this thread in the future, let me break it out visually

April 2020 Deadline

Any new app referencing UIWebView APIs will be declined.

December 2020 Deadline

Any app updates referencing UIWebView APIs will be declined.

Regards,
Lance | Team Lead - US DevTools Support
Progress Telerik

Hello Sadanan,

Telerik UI for Xamarin does not use UIWebView. It is actually a vestigial piece of code that was accidentally left in Xamarin.Forms. Microsoft removed it in XF 4.5.

Apple was going to stop accepting submissions in April 2020, but they moved that to December 2020. You can see this mentioned in an email screenshot here.

Regardless, we have been working hard to make sure everything works in our release so you can target Xamarin.Forms 4.5 and not be blocked by that issue. Make sure you're subscribed to this ticket to see when the status changes from In Development to Completed.

Regards,
Lance | Team Lead - US DevTools Support
Progress Telerik

Hi Ros,

That situation in unrelated to XamarinForms version or this feature request. I will provide an answer below. However, if you have any further questions, please open a new ticket so that we can better assist you.

Understanding Linker Behavior and LinkSkip

The reason you're seeing that problem is because when you set the linker to LinkAll, the compiler will strip out all the external code that you do not explicitly reference. This means any Telerik controls will also be stripped out, leading to what you see.

Full linking (LinkAll) is not supported in UI for Xamarin, as the compiler will remove all the external code that isn't directly referenced by your code. You can attempt to avoid this by instructing the linker to skip the external controls. See the Microsoft documentation here https://docs.microsoft.com/en-us/xamarin/ios/deploy-test/linker?tabs=windows#skipping-assemblies

Specifically, add a --linkskip argument for every Telerik assembly that your project is using. For example, if you're only using RadBorder, then you would have the following assembly references that need to be skipped

--Telerik.Xamarin.iOS --Telerik.XamarinForms.Primitives

You will need to add a linkskip argument for every assembly separately. The Microsoft documentation I linked to above explains in more detail.

Regards,
Lance | Team Lead - US DevTools Support
Progress Telerik