MSBuildWorkspace OpenProjectAsync 有空文档

Question

我通过创建了一个简单的控制台应用程序dotnet new console

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

</Project>

然后我在另一个应用程序中编写了一段代码来获取Roslyn的编译结果

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="CommandLineParser" Version="2.8.0" />
    <PackageReference Include="McMaster.Extensions.CommandLineUtils" Version="3.0.0" />
    <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.Common" Version="3.6.0-4.final" />
    <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="3.6.0-4.final" />
    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.6.0-4.final" />
    <PackageReference Include="Microsoft.Build" Version="16.5.0" />
    <PackageReference Include="PowerArgs" Version="3.6.0" />
  </ItemGroup>

</Project>

var workspace = MSBuildWorkspace.Create();
workspace.LoadMetadataForReferencedProjects = true;
var project = workspace.OpenProjectAsync(@"C:\...\Desktop\sample\sample.csproj").Result;
var compilation = project.GetCompilationAsync().Result;

但是Documents的长度是0所以我又写了一段代码来找出问题所在

var diagnostics = workspace.Diagnostics;
foreach (var diagnostic in diagnostics)
{
    Console.WriteLine(diagnostic.Message);
}

错误是（VS）：

Msbuild failed when processing the file 'C:\...\Desktop\sample\sample.csproj' with message: The SDK 'Microsoft.NET.Sdk' specified could not be found.  C:\...\Desktop\sample\sample.csproj

在《骑士》中：

Msbuild failed when processing the file 'C:\...\Desktop\sample\sample.csproj' with message: MSB0001: Internal MSBuild Error: Type information for Microsoft.Build.Utilities.ToolLocationHelper was present in the whitelist cache as Microsoft.Build.Utilities.ToolLocationHelper, Microsoft.Build.Utilities.Core, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a but the type could not be loaded. unexpectedly null

我的 dotnet 核心信息：

.NET Core SDK (reflecting any global.json):
 Version:   3.1.201
 Commit:    b1768b4ae7

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.18362
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\3.1.201\

Host (useful for support):
  Version: 3.1.3
  Commit:  4a9f85e9f8

.NET Core SDKs installed:
  3.1.101 [C:\Program Files\dotnet\sdk]
  3.1.102 [C:\Program Files\dotnet\sdk]
  3.1.201 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

我应该怎么做才能得到结果？

Answer 1

我最近遇到了这个错误。

为了让它发挥作用，我必须确保：

• Microsoft.Build.Locator <- 查找 .NET 安装的位置
• Microsoft.CodeAnalysis.CSharp.Workspaces
• Microsoft.CodeAnalysis.Workspaces.MSBuild
• Microsoft.CodeAnalysis.VisualBasic.Workspaces <- 仅在执行 VB 操作时需要

然后在我的代码中我可以写

MSBuildLocator.RegisterDefaults(); // Register location of .NET SDK

var workspace = MSBuildWorkspace.Create();
var project = await workspace.OpenProjectAsync(@"C:\project.csproj").ConfigureAwait(false);
var compilation = await project.GetCompilationAsync().ConfigureAwait(false);

值得注意的是，Microsoft.Build.Locator 1.5.3 目前存在一个问题 ( https://github.com/microsoft/MSBuildLocator/issues/179 )，会产生相同的错误消息，因此您应该使用 1.4.1，直到提供了修复