无法在服务解析源生成器中使用 MSBuild 属性

Question

I use Injectio and I'm having issue resolving the MSBuild properties. These are also documented in the source generator cookbook .

I made a simple Console application as a minimal reproducible example and initially added Injectio as a NuGet package which I then replaced with local Injectio project reference, so that it helps me debug the MSBuild properties and see what's wrong, more specifically this line of code :

    public void Initialize(IncrementalGeneratorInitializationContext context)
    {
        if (!Debugger.IsAttached)
        {
            Debugger.Launch();
        }

        ...

It ignores the property group below in my .csproj file. Why? Do I have to do CompilerVisibleProperty or something? This was also documented in the Injectio README , scroll down to the bottom.

    <PropertyGroup>
        <InjectioName>Library</InjectioName>
    </PropertyGroup>

All this property is supposed to do is let me use custom name for the registrator instead of services.AddTest() , eg in this case it should be services.AddLibrary() .

    .ConfigureServices(services =>
    {
        services.AddTest(); // Expected: => services.AddLibrary()
    })

Test.csproj

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net7.0</TargetFramework>
        <ImplicitUsings>enable</ImplicitUsings>
        <Nullable>enable</Nullable>
    </PropertyGroup>

    <PropertyGroup>
        <InjectioName>Library</InjectioName>
    </PropertyGroup>
    
    <ItemGroup>
        <PackageReference Include="Injectio" Version="1.0.33" />
        <PackageReference Include="Microsoft.Extensions.Hosting" Version="7.0.0" />
    </ItemGroup>
    
</Project>

Program.cs

using Injectio.Attributes;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

var host = new HostBuilder()
    .ConfigureServices(services =>
    {
        services.AddTest();
    })
    .ConfigureLogging(x => x.AddConsole())
    .UseConsoleLifetime()
    .Build();

await host.RunAsync();

[RegisterSingleton(ServiceType = typeof(IHostedService))]
internal sealed class Worker : BackgroundService
{
    private readonly ILogger<Worker> _logger;
    private readonly PeriodicTimer _timer = new(TimeSpan.FromSeconds(10));

    public Worker(ILogger<Worker> logger)
    {
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (await _timer.WaitForNextTickAsync(stoppingToken))
        {
            try
            {
                _logger.LogInformation("Worker running at: {Time}", DateTimeOffset.Now);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Oh, no! Something bad happened");
            }
        }
    }
}

Answer 1

It seems like I had to add CompilerVisibleProperty to the .csproj file, so it recognizes the MSBuild property.

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net7.0</TargetFramework>
        <ImplicitUsings>enable</ImplicitUsings>
        <Nullable>enable</Nullable>
        <IsPackable>false</IsPackable>
        <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
    </PropertyGroup>

    <PropertyGroup>
        <InjectioName>Library</InjectioName>
    </PropertyGroup>

    <ItemGroup>
        <CompilerVisibleProperty Include="InjectioName" />
    </ItemGroup>
    
    <ItemGroup>
        <PackageReference Include="Injectio" Version="1.0.33" />
        <PackageReference Include="Microsoft.Extensions.Hosting" Version="7.0.0" />
    </ItemGroup>
    
</Project>