Hi,

Marking this as Declined due to inactivity and no further reports or reproducible projects available. If there are any future incidents, feel free to reply here and we will be notified to investigate further.

Regards,
Lance | Technical Support Engineer, Principal
Progress Telerik

Hi Nik,

Thank you for the additional information. It does help me narrow down the problem, but without seeing your code I'm only able to take random educated guesses at what it might be..

The only think I can think of is one edge case in which the model that was used for the DataForm had a base class in which properties were marked with the [Ignore] attribute.  The solution for that issue was to set the property access modifier to internal.

For example, the edge case was the DataForm was used to edit the entities of an Azure Mobile Services item. Those entity classes have a base class with properties used by the database, but are never needed in the UI (and should never be changed by the user).

So the fix was to mark anything with the Ignore attribute to internal. Here's a screenshot of that very code change:




If you still get the crashes, please share both the DataForm and model classes code so that I can investigate directly.

Hopefully this help. 

Regards,
Lance | Technical Support Engineer, Principal
Progress Telerik

Hello Nik,

This may be due to missing dependencies (particularly SkiaSharp) or code stripped out by the Linker. However, I am unable to give you a specific cause without a test project that replicates the crash. 

I have done some preliminary tests and do not observe the problem on my side. My test project is attached so that you can observe this as well.


Xamarin.Forms 4.0

We do not yet officially support Xamarin.Forms 4.x yet. Although we did recently release a fix for other unrelated XF 4.x problems in the 2019.2.603 release, there may be other unknown issues. You can update to the latest release of  XF v.3.6 to ensure 100% compatibility. 

That being said, I did perform my tests using both XF 3.6 and 4.0. In both scenarios, I did not experience any errors or crashes.

Note: It could still be that you're using a different configuration of editors and attributes. If you can replicate the error with my attached demo, please send the updated code back to me. See the "Further Investigation" section below.


SkiaSharp

When the DataForm first renders, it is using display elements to show the values (e.g. Label). However, when you edit a field, it switches over to the Editor for that field. Some editors, and many other UI for Xamarin controls, require SkiaSharp to render.

First, double check that you've got all the required dependencies for the DataForm, then make sure that you have installed the following NuGet packages to the solution's projects:

- SkiaSharp (install to all projects)
- SkiaSharp.Views (install to all projects, except class library)
- SkiaSharp.Views.Forms (install to all projects)


Linker Settings

It is also possible that the iOS Linker behavior is stripping out the DataForm's components. Here are two things you can do to ensure it's not being stripped out:

1. Make sure you have Xamarin XAML Compilation enabled in the class library project. It can be done in App.xaml.cs, but is usually set in a separate class like this:



2. In the iOS project properties, make sure the iOS Linker Behavior is not set to Link All




Further Investigation

Since there are a lot of moving parts to this setup (e.g. target SDK, dependencies, deployment target, etc), the fastest route to a solution is if you could update the attached demo so that the crash occurs. With this I can escalate to the development team for further investigation.

I look forward to your reply.

Regards,
Lance | Technical Support Engineer, Principal
Progress Telerik