c# - VS2017 MSBuildWorkspace fails opening with converted ASP.Net Core Web application 解决方案

Question

我已经使用 Microsoft.CodeAnalysis 包设置了一些解决方案健全性测试，一切都很顺利，因为我安装了 VS2017 并转换了我的 ASP.Net Core Web 应用程序。由于 csproj 文件简化 ( https://blogs.msdn.microsoft.com/dotnet/2016/12/12/updating-visual-studio-2017-rc-net-core-tooling-improvements/ )，似乎无法再打开该解决方案。我使用的代码如下:

var workspace = MSBuildWorkspace.Create();
var solution = workspace.OpenSolutionAsync(slnPath).Result;

这是我遇到的异常:

Microsoft.Build.Exceptions.InvalidProjectFileException
The default XML namespace of the project must be the MSBuild XML namespace. If the project is authored in the MSBuild 2003 format, please add xmlns="http://schemas.microsoft.com/developer/msbuild/2003" to the <Project> element. If the project has been authored in the old 1.0 or 1.2 format, please convert it to MSBuild 2003 format.
   at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args)
   at Microsoft.Build.Construction.ProjectParser.Parse()
   at Microsoft.Build.Construction.ProjectParser.Parse(XmlDocumentWithLocation document, ProjectRootElement projectRootElement)
   at Microsoft.Build.Construction.ProjectRootElement.Create(XmlReader xmlReader, ProjectCollection projectCollection)
   at Microsoft.CodeAnalysis.MSBuild.ProjectFileLoader.<LoadProjectAsync>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.ProjectFileLoader.<LoadProjectFileAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.<LoadProjectAsync>d__23.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.<GetOrLoadProjectAsync>d__22.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.<LoadSolutionInfoAsync>d__18.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildWorkspace.<OpenSolutionAsync>d__18.MoveNext()

在我看来，新的 csproj 结构并未得到完全支持。一个可能的解决方案可能是在没有转换项目的情况下创建一个单独的解决方案，但这确实是一种解决方法。有什么想法吗？

编辑:

我尝试按照错误消息中的建议进行操作，即像这样添加 xmlns 属性:

<Project Sdk="Microsoft.NET.Sdk.Web" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <TargetFramework>net452</TargetFramework>
    <RuntimeIdentifier>win7-x86</RuntimeIdentifier>
    <GenerateDocumentationFile>true</GenerateDocumentationFile>
    <PreserveCompilationContext>true</PreserveCompilationContext>
    <AssemblyName>Arcmedia.Esl.WebApp.Api</AssemblyName>
    <OutputType>Exe</OutputType>
    <PackageId>Arcmedia.Esl.WebApp.Api</PackageId>
  </PropertyGroup>
  <ItemGroup>
    <None Include="App.config" />
    <Content Update="wwwroot;web.config">
      <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
    </Content>
  </ItemGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.0" />
  </ItemGroup>
  <ItemGroup Condition=" '$(TargetFramework)' == 'net452' ">
    <Reference Include="System" />
    <Reference Include="Microsoft.CSharp" />
  </ItemGroup>
  <ItemGroup>
    <ProjectReference Include="..\xyz\abc.def.csproj" />
  </ItemGroup>
</Project>

但这并没有解决问题，因为现在我得到另一个异常:

Microsoft.Build.Exceptions.InvalidProjectFileException
The attribute "Update" in element <Content> is unrecognized.
   at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args)
   at Microsoft.Build.Internal.ProjectXmlUtilities.ThrowProjectInvalidAttribute(XmlAttributeWithLocation attribute)
   at Microsoft.Build.Internal.ProjectXmlUtilities.VerifyThrowProjectAttributes(XmlElementWithLocation element, String[] validAttributes)
   at Microsoft.Build.Construction.ProjectParser.ParseProjectItemElement(XmlElementWithLocation element, ProjectItemGroupElement parent)
   at Microsoft.Build.Construction.ProjectParser.ParseProjectItemGroupElement(XmlElementWithLocation element, ProjectElementContainer parent)
   at Microsoft.Build.Construction.ProjectParser.ParseProjectRootElementChildren(XmlElementWithLocation element)
   at Microsoft.Build.Construction.ProjectParser.Parse()
   at Microsoft.Build.Construction.ProjectParser.Parse(XmlDocumentWithLocation document, ProjectRootElement projectRootElement)
   at Microsoft.Build.Construction.ProjectRootElement.Create(XmlReader xmlReader, ProjectCollection projectCollection)
   at Microsoft.CodeAnalysis.MSBuild.ProjectFileLoader.<LoadProjectAsync>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.ProjectFileLoader.<LoadProjectFileAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.<LoadProjectAsync>d__23.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.<GetOrLoadProjectAsync>d__22.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.<LoadSolutionInfoAsync>d__18.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildWorkspace.<OpenSolutionAsync>d__18.MoveNext()

因此，回到我最初的结论，似乎在尝试使用 Microsoft.CodeAnalysis.MSBuild.MSBuildWorkspace.OpenSolutionAsync 时未正确支持新的简化 csproj 文件结构

Answer 1

出现此问题是因为项目文件正在使用 VS2017 csproj 的新架构格式，但 msbuild 是从您计算机上的旧安装(可能是 VS2015)运行的。发生这种情况是因为您拥有的 Roslyn MSBuildWorkspace 是针对不理解新格式的先前版本的 MSBuild API 构建的，并且在您的计算机上使用该版本而不是较新版本。如果计算机上没有旧版本，MSBuildWorkspace 会立即失败并出现类型加载异常。

MSBuildWorkspace 已更新到较新的 VS2017 版本，但尚未在 nuget 上。您可以从 Roslyn myget 提要中获取 if。

查看此 github 问题以获取更多详细信息:https://github.com/dotnet/roslyn/issues/16886