遇到这个问题

按以下步骤求解

清除packages文件夹中的内容(先备份) 使用“更新-包-重新安装”从包管理控制台的NuGet中重新获取和重新安装包(Tools -> NuGet包管理器->包管理控制台) 从.csproj文件中删除冗余路径。注意:NuGet会添加新的路径到csproj文件，但它不会删除旧的路径… (有一些机会csproj文件有多个路径为同一文件)

为什么我们需要“Microsoft.Net.Compilers.props”? 它将提供“\roslyn”文件夹。如果没有它，你可能仍然可以编译程序，但不能使用@{html.RenderPartial…}

我通过从.csproj文件中删除这段代码来解决我的问题:

<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>

Not sure if this will help anyone, but I had this issue come up when I deleted the source code from my local machine without having ever saved the solution file to TFS. (During initial development, I was right-clicking and checking in the project in Solution Explorer, but forgot to ever check in the solution itself.) When I needed to work on this again, all I had in TFS was the .csproj file, no .sln file. So in VS I did a File --> Source Control --> Advanced -- Open from Server and opened the .csproj file. From there I did a Save All and it asked me where I wanted to save the .sln file. I was saving this .sln file to the project directory with the other folders (App_Data, App_Start, etc.), not the top level directory. I finally figured out that I need to save the .sln file up a directory from the project folder so it's on the same level as the project folder. All my paths resolved and I was able to build it again.

对于DevOps/构建工程师，您可能可以针对受影响的SLN或缺乏SLN的项目修复此运行nuget恢复。我必须为我们所有UWP项目的CI/CD构建这样做。

Make sure nuget is installed on the build slave either in Visual Studio or standalone. If it's the latter, make sure it's in PATH and skip step 2. Either open the VS Dev CMD console, or load it via an already open one, which you can do with the instructions below: VS2015 call "%VS140COMNTOOLS%VsDevCmd.bat" or VS2017 call "%ProgramFiles(x86)%\Microsoft Visual Studio\2017\Enterprise\Common7\Tools\VsDevCmd.bat" call nuget restore MyStuff.SLN or call nuget restore MyStuff.csproj if there's no SLN.

对我来说，问题是当我将解决方案复制到一个新文件夹并打开它时，它缺少如下所示的Nuget文件夹。我复制了这个文件夹，一切正常。注意:这个文件夹在我们的源代码控制中，但不在这个解决方案项目中，它在上面一个目录中。

只要启用NuGet包恢复。 右键单击您的解决方案>选择“启用NuGet包恢复”。

这将创建带有NuGet的. NuGet文件夹。配置文件，并解决了我的问题。