Analyzer reports unused constructor for MEF components.

This issue has been moved from a ticket on Developer Community.

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Create a class with an Export attribute and a private constructor with an ImportingConstructor attribute on it. This denotes a MEF component that will invoke the private ctor instead of the default (parameterless) one. However, the VS code analyzer still “dims” the ctor and reports it as unused.

    [Export(ExportContractNames.ProjectTreeProviders.PhysicalViewRootGraft, typeof(IProjectTreeProvider))]
    internal class GlobalDesignerProjectTreeProvider : ProjectTreeProviderBase
    {
        [ImportingConstructor]
        private GlobalDesignerProjectTreeProvider(
            IProjectThreadingService threadingService,
            UnconfiguredProject project)
            : base(threadingService, project, configuredProjectExportsRequired: true)
        {
        }

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Original Comments

Mila Zhou [MSFT] on 8/13/2020, 11:06 PM:

Could you please tell me what type of project you are? Web or others? Some screenshots will be better.

Feedback Bot on 8/17/2020, 02:55 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

Feedback Bot on 8/17/2020, 09:33 AM:

Thank you for sharing your feedback! Our teams prioritize action on product issues with broad customer impact. See details at: https://docs.microsoft.com/en-us/visualstudio/ide/report-a-problem?view=vs-2019#faq. In case you need answers to common questions or need assisted support, be sure to use https://visualstudio.microsoft.com/vs/support/. We’ll keep you posted on any updates to this feedback.

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Original Solutions

kirk solved on 8/14/2020, 06:48 AM, 0 votes:

It probably happens in any C# scenario, but the one above is a C# class library project targeting .NET 4.7.

[mavasani]

Yes, I would be fine with modifying the analyzer here to ignore MEF import/export member symbols from analysis.

[sharwell]

@jmarolf there are a wide variety of reflection-based cases where that sentiment holds. Given the accessibility change has proven reliable as a design improvement to avoid this warning, I don’t see a lot of value in implementing this special case knowing there is no way we can cover so many others.