Visual Studio 2022 v17.12 breaks binding to [ObservableProperty]

[bjorn-malmo]

Version Used:

Building the application using Visual Studio 2022 v17.12.x breaks Binding to [ObservableProperty]
Building the application using Visual Studio 2022 v17.10.6 works perfectly

Please see original issue:
CommunityToolkit/dotnet#1011

Steps to Reproduce:

1. Project PropertyBindingTest.sln in repo https://github.com/bjorn-malmo/bug-free-happiness/.
2. Build and run on Visual Studio 2022 v17.12.x
3. Note that the Binding to ObservableProperty on object deriving from Control is not updated
4. However, running the same application in Visual Studio 2022 v17.10.6 works

A minimal repro, with source-code provided, is ideal. Most compiler/language issues can be distilled into a snippet that can be pasted into sharplab.

Diagnostic Id:

If this is a report about a bug in an analyzer, please include the diagnostic ID and message if possible (e.g. "IDE0030: Use coalesce expression").

Expected Behavior:
Binding updating value in UI

Actual Behavior:
Binding not updating UI value for property

[CyrusNajmabadi]

What do you mean by "breaks binding"?

[bjorn-malmo]

The binding will not update as a result of a PropertyChanged event notification. The issue has been reproduced by CommunityToolkit (see linked issue above), but closed as it is not deemed a problem in CommunityToolkit, but probably something with code generation, as the UI will update if the program is run in older Visual Studio 2022, but not in the latest version.

[CyrusNajmabadi]

Again, I don't know what "breaks binding" means.

[CyrusNajmabadi]

The binding will not update as a result of a PropertyChanged event notification

I don't know what this means. What event notification are you referring to? What is a "binding" here?

but probably something with code generation,

What code generation?

if the program is run in older Visual Studio 2022, but not in the latest version.

What code was generated in older versions of visual studio, and what code is now generated in the latest version?

[bjorn-malmo]

OK, I'll try to explain in a different way:

1. Create a WinUI 3 Custom Control
2. Using CommunityToolkit, attribute the class [ObservableObject]
3. Create a field and attribute it [ObservableProperty]
4. In the control's template, bind to the property. Text="{Binding MyValue, RelativeSource={RelativeSource TemplatedParent}}" (In this situation, x:Bind cannot be used, right?)
5. Update the value of the MyValue property. In the sample I use a RelayCommand

Sample application found here: Project PropertyBindingTest.sln in repo https://github.com/bjorn-malmo/bug-free-happiness/

Now, compile the application using Visual Studio 2022 v17.10

Run the application, update the value of the MyValue property and watch the UI display the new value in the text property.

In this situation, I consider the "Binding" to be working!

Update Visual Studio 2022 to v17.12

Run the same application again, update the value of the MyValue property, and watch the UI not responding to the update. The PropertyChanged event is raised however.

In this situation, I consider the "Binding" to be broken! I don't know what is broken, but it doesn't work. No update. No change.

Screenshot from application run in older version:

Screenshot from application run in new version:

Note the text block on top clearly saying Initial value in the bottom most image!

[CyrusNajmabadi]

Why do you think this is Roslyn? We are the c# to IL compiler. What is different between the two compiled programs that is causing the issue here?

[CyrusNajmabadi]

In the control's template, bind to the property. Text="{Binding MyValue, RelativeSource={RelativeSource TemplatedParent}}" (In this situation, x:Bind cannot be used, right?)

This appears to be some different language, unrelated to c#/vb. Perhaps an issue with that language, or whatever ui toolkit you are using?

[huoyaoyuan]

This is WinUI xaml compiler and belongs to https://github.com/microsoft/microsoft-ui-xaml

[CyrusNajmabadi]

Closing as this is external. I can't move issues from dotnet to Microsoft, so you'll have to create a new issue there