使用Roslyn加载sln文件时编译失败，但在Visual Studio中可以编译

Question

我正在制作一个工具，并使用Roslyn加载解决方案文件，然后获取其中项目的编译。但是出现了一些错误（5000+）...以下是其中几个：

CS0518：未定义或导入预定义类型“System.String” CS0246：找不到类型或命名空间名称“System”（是否缺少using指令或程序集引用？）

以下代码有两次尝试：

#1 - 尝试立即编译-我在第一时间尝试的内容...这个有5000+个错误 #2 - 编译添加系统引用-我尝试使它工作，它确实工作了...但不如预期

代码：

var workspace = MSBuildWorkspace.Create();
var solution = await workspace.OpenSolutionAsync(@"C:\Projects\MyLib\MyLib.sln");

var sortedProject = solution
    .GetProjectDependencyGraph()
    .GetTopologicallySortedProjects()
    .Select(solution.GetProject);

foreach (var project in sortedProject)
{
    // 
    // #1 - trying to compile right away
    //
    var compilation1 = await project.GetCompilationAsync();
    var diag1 = compilation1.GetDiagnostics();

    // 
    // #2 - compiling adding system references
    // 
    var assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
    var project2 = project.AddMetadataReferences(
        new[]
                    {
                        MetadataReference.CreateFromFile(
                            Path.Combine(assemblyPath, "mscorlib.dll")),
                        MetadataReference.CreateFromFile(
                            Path.Combine(assemblyPath, "System.dll")),
                        MetadataReference.CreateFromFile(
                            Path.Combine(assemblyPath, "System.Core.dll")),
                    });

    var compilation2 = await project2.GetCompilationAsync();
    var diag2 = compilation2.GetDiagnostics();
}

正在使用的Roslyn版本：1.0.0.0-beta2

问题是：

既然我已经加载了使用Visual Studio 2012保存、针对.Net Framework v4.5进行编译并在IDE中成功编译的有效解决方案文件...为什么我还要添加系统引用才能使它起作用呢？

我期望它已经带有正确的.Net Framework版本的系统引用。这意味着，即使#2也不总是起作用，因为我必须找到正确的.Net Framework版本文件，而不是使用我正在编译的工具的文件。

编辑：

以下是csproj文件的内容：

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProjectGuid>{E8757858-B17B-43D4-AA13-412E552386DC}</ProjectGuid>
    <OutputType>Library</OutputType>
    <AppDesignerFolder>Properties</AppDesignerFolder>
    <RootNamespace>DataStructures</RootNamespace>
    <AssemblyName>DataStructures</AssemblyName>
    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
    <FileAlignment>512</FileAlignment>
    <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\</SolutionDir>
    <RestorePackages>true</RestorePackages>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\Debug.net45\</OutputPath>
    <DefineConstants>TRACE;DEBUG;net45</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <OutputPath>bin\Release.net45\</OutputPath>
    <DefineConstants>TRACE;net45</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <DocumentationFile>bin\Release.net45\DataStructures.XML</DocumentationFile>
  </PropertyGroup>
  <PropertyGroup>
    <SignAssembly>true</SignAssembly>
  </PropertyGroup>
  <PropertyGroup>
    <AssemblyOriginatorKeyFile>masb.public.snk</AssemblyOriginatorKeyFile>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Core" />
    <Reference Include="System.Xml.Linq" />
    <Reference Include="System.Data.DataSetExtensions" />
    <Reference Include="Microsoft.CSharp" />
    <Reference Include="System.Data" />
    <Reference Include="System.Xml" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Continuous\ContinuousSet.cs" />
    <Compile Include="Continuous\ContinuousSetEqualityComparer.cs" />
    <Compile Include="Continuous\Interval.cs" />
    <Compile Include="Continuous\ISetOperator.cs" />
    <Compile Include="Continuous\PointState.cs" />
    <Compile Include="Continuous\RedundancyType.cs" />
    <Compile Include="EnumerableExtensions.cs" />
    <Compile Include="DictionaryExtensions.cs" />
    <Compile Include="IImmutable.cs" />
    <Compile Include="IImmutablePrototype.cs" />
    <Compile Include="Immutable\FuncCached.cs" />
    <Compile Include="Immutable\IImmutableSpecificTreeBuilderWithContext.cs" />
    <Compile Include="Immutable\IImmutableTreeBuilderWithContext.cs" />
    <Compile Include="Immutable\IMayBeImmutable.cs" />
    <Compile Include="Immutable\ImmutableSpecificTreeBuilderWithContext.cs" />
    <Compile Include="Immutable\ImmutableTreeBuilderWithContext.cs" />
    <Compile Include="Immutable\ImmutableTreeBuilderWithContextExtensions.cs" />
    <Compile Include="Immutable\IReadableForest.cs" />
    <Compile Include="Immutable\IImmutableSpecificTreeBuilder.cs" />
    <Compile Include="Immutable\IImmutableTreeBuilder.cs" />
    <Compile Include="Immutable\ImmutableCollection.cs" />
    <Compile Include="Immutable\ImmutableForestExtensions.cs" />
    <Compile Include="Immutable\ImmutableSpecificTreeBuilder.cs" />
    <Compile Include="Immutable\ImmutableTreeBuilder.cs" />
    <Compile Include="Immutable\ImmutableTreeBuilderExtensions.cs" />
    <Compile Include="Immutable\TreeBuildingContextBase.cs" />
    <Compile Include="Immutable\TreeBuildingContext.cs" />
    <Compile Include="Immutable\Tree\Branch.cs" />
    <Compile Include="Immutable\Tree\INodeFactory.cs" />
    <Compile Include="Immutable\Tree\INonRoot.cs" />
    <Compile Include="Immutable\Tree\Node.cs" />
    <Compile Include="Immutable\ImmutableForest.cs" />
    <Compile Include="Immutable\Tree\IBranch.cs" />
    <Compile Include="Immutable\Tree\ILeaf.cs" />
    <Compile Include="Immutable\Tree\INode.cs" />
    <Compile Include="Immutable\Tree\IRoot.cs" />
    <Compile Include="Immutable\Tree\Leaf.cs" />
    <Compile Include="Immutable\Tree\NodeExtensions.cs" />
    <Compile Include="Immutable\Tree\NonRoot.cs" />
    <Compile Include="Immutable\Tree\Root.cs" />
    <Compile Include="Immutable\Tree\RootBranch.cs" />
    <Compile Include="Immutable\Tree\RootLeaf.cs" />
    <Compile Include="Immutable\ImmutableTree.cs" />
    <Compile Include="Immutable\Tree\Visitor.cs" />
    <Compile Include="JetBrains.Annotations\JetBrains.Annotations.cs" />
    <Compile Include="Monads\IOption.cs" />
    <Compile Include="Monads\None.cs" />
    <Compile Include="Monads\OptionExtensions.cs" />
    <Compile Include="Monads\Some.cs" />
    <Compile Include="Properties\AssemblyInfo.cs" />
    <Compile Include="SystemExtensions\ObjectExtensions.cs" />
  </ItemGroup>
  <ItemGroup>
    <None Include="masb.public.snk" />
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
  <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
    <PropertyGroup>
      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
    </PropertyGroup>
    <Error Condition="!Exists('$(SolutionDir)\.nuget\NuGet.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\.nuget\NuGet.targets'))" />
  </Target>
  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
       Other similar extension points exist, see Microsoft.Common.targets.
  <Target Name="BeforeBuild">
  </Target>
  <Target Name="AfterBuild">
  </Target>
  -->
</Project>

- Miguel Angelo

---

什么类型的项目？什么错误？ - SLaks

C＃项目（csproj）...所有错误都是引用错误...我已编辑问题并添加了一些。 - Miguel Angelo

第一种方法“应该”可以工作。如果您进行调试，项目是否有任何引用？这些项目中是否有任何可移植类库？ - Kevin Pilch

我稍后会尝试隔离这个问题……现在无法处理。 - Miguel Angelo

我找到了答案... =) - Miguel Angelo

Answer 1

我终于找到了答案...我用的是.Net Framework 4.6预览版来制作工具。

我已经卸载了Visual Studio 2015，但没有卸载框架4.6。

因此，在创建工具项目时，我错误地选择了Visual Studio 2013中的.Net Framework 4.5.3（在安装VS2015 CTP后出现在VS2013中）。

通过将框架切换到4.5，它可以正常工作并正确加载MetadataReferences。

- Miguel Angelo