C# NET5.0源生成器基本示例不生成输出

Question

我正在尽可能地从Microsoft网站示例复制所有的东西，但是没有任何东西是生成的。我创建了一个MCVE，试图找出为什么会发生以下错误：

Warning CS8034  
Unable to load Analyzer assembly C:\Users\me\source\repos\SourceGenTest\SourceGenerators\bin\Debug\netstandard2.0\SourceGenerators.dll: 
Could not find file 'C:\Users\me\source\repos\SourceGenTest\SourceGenerators\bin\Debug\netstandard2.0\SourceGenerators.dll'.
SourceGenLibrary        1   Active

我已经检查了提供的路径，并且SourceGenerators.dll存在。这个错误对我来说毫无意义。

注意:我提供的MCVE中的，显然没有构建警告。不知道为什么，但仍然没有来自源生成器的输出。

我的目标是拥有这样的工作流：

SourceGenerators (class library)
    is consumed by
        SourceGenLibrary (class library)
            is consumed by
                SourceGenConsole (Console project)

因此，我希望分析器在类库中生成定义，这些定义将在许多项目之间共享。上面的工作流将其简化为一个依赖于一个库的项目，该库依赖于源生成器，以尽可能保持MCVE。

因为复制所有这些东西很烦人，所以如果你懒惰的话，这里有一个上传链接：下载链接MCVE (据推测在发布一周后到期，但源代码在下面)。

相关信息：

$ dotnet --version
5.0.201

$ dotnet --list-sdks
5.0.103 [C:\Program Files\dotnet\sdk]
5.0.201 [C:\Program Files\dotnet\sdk]

这些是源文件和它们包含的内容。

/SourceGenTest.sln

Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio Version 16
VisualStudioVersion = 16.0.31112.23
MinimumVisualStudioVersion = 10.0.40219.1
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SourceGenLibrary", "SourceGenLibrary\SourceGenLibrary.csproj", "{8702B80A-ACA3-4546-BBE8-A9FEE686A758}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SourceGenerators", "SourceGenerators\SourceGenerators.csproj", "{D693D3B2-F981-4D6D-AC97-B8C636E8C5C0}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SourceGenConsole", "SourceGenConsole\SourceGenConsole.csproj", "{3730848C-847C-4DF9-A0B3-5ADB5FE9D1E0}"
EndProject
Global
    GlobalSection(SolutionConfigurationPlatforms) = preSolution
        Debug|Any CPU = Debug|Any CPU
        Release|Any CPU = Release|Any CPU
    EndGlobalSection
    GlobalSection(ProjectConfigurationPlatforms) = postSolution
        {8702B80A-ACA3-4546-BBE8-A9FEE686A758}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {8702B80A-ACA3-4546-BBE8-A9FEE686A758}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {8702B80A-ACA3-4546-BBE8-A9FEE686A758}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {8702B80A-ACA3-4546-BBE8-A9FEE686A758}.Release|Any CPU.Build.0 = Release|Any CPU
        {D693D3B2-F981-4D6D-AC97-B8C636E8C5C0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {D693D3B2-F981-4D6D-AC97-B8C636E8C5C0}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {D693D3B2-F981-4D6D-AC97-B8C636E8C5C0}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {D693D3B2-F981-4D6D-AC97-B8C636E8C5C0}.Release|Any CPU.Build.0 = Release|Any CPU
        {3730848C-847C-4DF9-A0B3-5ADB5FE9D1E0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {3730848C-847C-4DF9-A0B3-5ADB5FE9D1E0}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {3730848C-847C-4DF9-A0B3-5ADB5FE9D1E0}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {3730848C-847C-4DF9-A0B3-5ADB5FE9D1E0}.Release|Any CPU.Build.0 = Release|Any CPU
    EndGlobalSection
    GlobalSection(SolutionProperties) = preSolution
        HideSolutionNode = FALSE
    EndGlobalSection
    GlobalSection(ExtensibilityGlobals) = postSolution
        SolutionGuid = {A3752997-47E1-4086-87C8-1583B5E0EDF1}
    EndGlobalSection
EndGlobal

/SourceGenerators/SourceGenerators.csproj

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

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <LangVersion>preview</LangVersion>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.2" />
    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.9.0" />
  </ItemGroup>

</Project>

/SourceGenerators/Class1.cs

using System.Text;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Text;

namespace SourceGeneratorSamples
{
    [Generator]
    public class HelloWorldGenerator : ISourceGenerator
    {
        public void Execute(GeneratorExecutionContext context)
        {
            // begin creating the source we'll inject into the users compilation
            var sourceBuilder = new StringBuilder(@"
            using System;
            namespace HelloWorldGenerated
            {
                public static class HelloWorld
                {
                    public static void SayHello() 
                    {
                        Console.WriteLine(""Hello from generated code!"");
                        Console.WriteLine(""The following syntax trees existed in the compilation that created this program:"");
            ");

            // using the context, get a list of syntax trees in the users compilation
            var syntaxTrees = context.Compilation.SyntaxTrees;

            // add the filepath of each tree to the class we're building
            foreach (SyntaxTree tree in syntaxTrees)
            {
                sourceBuilder.AppendLine($@"Console.WriteLine(@"" - {tree.FilePath}"");");
            }

            // finish creating the source to inject
            sourceBuilder.Append(@"
                    }
                }
            }");

            // inject the created source into the users compilation
            context.AddSource("helloWorldGenerator", SourceText.From(sourceBuilder.ToString(), Encoding.UTF8));
        }

        public void Initialize(GeneratorInitializationContext context)
        {
        }
    }
}

/SourceGenLibrary/SourceGenLibrary.csproj

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

  <PropertyGroup>
    <TargetFramework>net5.0</TargetFramework>
    <LangVersion>preview</LangVersion>
    <AssemblyName>SourceGenLibrary</AssemblyName>
  </PropertyGroup>

  <ItemGroup>
    <ProjectReference Include="..\SourceGenerators\SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
  </ItemGroup>

</Project>

/SourceGenLibrary/Class1.cs

using System;

namespace SourceGenTest
{
    public class Class1
    {
        public static void Func()
        {
            //HelloWorldGenerator.HelloWorld.SayHello();
        }
    }
}

/SourceGenConsole/SourceGenConsole.csproj

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net5.0</TargetFramework>
    <LangVersion>preview</LangVersion>
  </PropertyGroup>

  <ItemGroup>
    <ProjectReference Include="..\SourceGenLibrary\SourceGenLibrary.csproj" />
  </ItemGroup>

</Project>

/SourceGenConsole/Program.cs

using System;

namespace SourceGenConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
        }
    }
}

Answer 1

对不起，之前的回答完全错了。此外，我的代表太低，不能发表评论，所以我提交这个。

我试图对3个项目做一些类似的事情，并得到一个类似的错误(尽管我还有很多其他问题)。我必须在底层项目中添加对源生成器的引用(在您的例子中是控制台)。此外，我还添加了一个Debugger.Launch()，它有助于深入研究具体问题。