[BUG] Toolkit warning when targeting net9.0 - Analyzers issue

[IeuanWalker]

Is there an existing issue for this?

• I have searched the existing issues

Did you read the "Reporting a bug" section on Contributing file?

• I have read the "Reporting a bug" section on Contributing file: https://github.com/CommunityToolkit/Maui/blob/main/CONTRIBUTING.md#reporting-a-bug

Current Behavior

Getting a warning when setting up the MAUI project to work with a unit test project -

Followed MS docs for adding a unit test project - https://learn.microsoft.com/en-us/dotnet/maui/deployment/unit-testing?view=net-maui-9.0
When i updated the TargetFrameworks i get the warning -

<TargetFrameworks>net9.0;net9.0-android;net9.0-ios</TargetFrameworks>

Tried using a preprocessor directives, but then get an error -

Expected Behavior

No warning for the base .net target framework

Steps To Reproduce

Update target frameworks of the app project -

 <TargetFrameworks>net9.0;net9.0-android;net9.0-ios</TargetFrameworks>

Link to public reproduction project repository

https://github.com/IeuanWalker/ToolkitAnalyzers

Environment

- .NET MAUI CommunityToolkit:11.1.0
- OS: Windows
- .NET MAUI: 9.0.30

Anything else?

No response

[ne0rrmatrix]

If you have toolkit nuget package in your csproj this is working as intended. We added the analyzer to force developers to add the toolkit to builder. If you do not add it to builder it will not work.

Please read out getting started guide here: https://learn.microsoft.com/en-us/dotnet/communitytoolkit/maui/get-started?tabs=CommunityToolkitMaui

var builder = MauiApp.CreateBuilder();
builder
    .UseMauiApp<App>()
    .UseMauiCommunityToolkit()

The above code is the absolute minimum required for your project not to have warnings/errors when loading maui toolkit even if you do absolutely nothing but add it to csproj file.

[bijington]

Have you tested this in an application targeting net9.0 as Leuan has reported?

[IeuanWalker]

@ne0rrmatrix .UseMauiCommunityToolkit() is added to the builder.

The issue is if you add .net9.0 as a target framework in your .csproj -

<TargetFrameworks>net9.0;net9.0-android;net9.0-ios</TargetFrameworks>

You then get this warning -

If you then wrap .UseMauiCommunityToolkit() in a preprocessor directives to fix the above warning, you then get the toolkit throwing the following analyser error -

[IeuanWalker]

So ideally, the toolkit analyser needs to be updated to handle .UseMauiCommunityToolkit() being wrapped in a preprocessor directives as I personally don't like suppressing warnings like the one above.