我研究了这个问题，但没有一个解决办法有效。我安装了Visual Studio Professional 2015，我正在使用TFS。我的NuGet版本是3.1.6。这个问题只发生在我的c# Web API/MVC项目中。
我得到以下错误:
这个项目引用了NuGet包(s)，这是缺失的
电脑。使用NuGet包还原来下载它们。更多的
信息，见http://go.microsoft.com/fwlink/?LinkID=322105。的
丢失的文件是
. . \ \ Microsoft.Net.Compilers.1.0.0 \制造\ Microsoft.Net.Compilers.props包
I do not have .nuget folder in my solutions.
I have a packages folder in the solution and when I delete it, it seems like NuGet does rebuild the dependencies but the project still has the above error.
I tried removing the project from TFS and it didn't fix it.
Along with the above error, all the references in the project have yellow warning signs and say they are missing.
When I checked the NuGet Package Manager for the project, everything that is "missing" has a green tick next to it, including Microsoft.Net.Compilers.
I tried adding a new Web API/MVC project and it faced a similar problem where most references such as Owin were "missing" with the yellow warning sign.
这似乎有多种原因。
对于我来说，.csproj文件包含了对Microsoft.Bcl.Build.targets两个不同版本的引用:
<Import Project="..\packages\Microsoft.Bcl.Build.1.0.14\tools\Microsoft.Bcl.Build.targets" Condition="Exists('..\packages\Microsoft.Bcl.Build.1.0.14\tools\Microsoft.Bcl.Build.targets')" />
<Target Name="EnsureBclBuildImported" BeforeTargets="BeforeBuild" Condition="'$(BclBuildImported)' == ''">
<Error Condition="!Exists('..\packages\Microsoft.Bcl.Build.1.0.14\tools\Microsoft.Bcl.Build.targets')" Text="This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=317567." HelpKeyword="BCLBUILD2001" />
<Error Condition="Exists('..\packages\Microsoft.Bcl.Build.1.0.14\tools\Microsoft.Bcl.Build.targets')" Text="The build restored NuGet packages. Build the project again to include these packages in the build. For more information, see http://go.microsoft.com/fwlink/?LinkID=317568." HelpKeyword="BCLBUILD2002" />
</Target>
<Import Project="..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets" Condition="Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets'))" />
</Target>
我删除了旧的参考，它解决了这个问题。
对于在这里遇到我遇到的问题(在构建服务器上恢复了一些包，但不是所有包)的任何人来说，对我来说，难题的最后一块是添加NuGet。config在我的解决方案的根文件中，是. sln文件的兄弟，正如David Ebbo在这里解释的:http://blog.davidebbo.com/2014/01/the-right-way-to-restore-nuget-packages.html。
从Ebbo的博客文章来看，文件内容对我来说很简单
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<packageSources>
<add key="nuget.org" value="https://www.nuget.org/api/v2/" />
</packageSources>
</configuration>
更新:
v3的NuGet API URL已更改(截至2016年9月)。从https://www.nuget.org/
<add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
