Visual Studio C#项目引用显示黄色感叹号

1打开web项目的.csproj 文件，找到下面代码 进行删除 即可。

<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\SQLite.3.13.0\build\net45\SQLite.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\SQLite.3.13.0\build\net45\SQLite.props'))" />
<Error Condition="!Exists('..\packages\System.Data.SQLite.Core.1.0.113.1\build\net451\System.Data.SQLite.Core.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\System.Data.SQLite.Core.1.0.113.1\build\net451\System.Data.SQLite.Core.targets'))" />
<Error Condition="!Exists('..\packages\cef.redist.x64.89.0.17\build\cef.redist.x64.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\cef.redist.x64.89.0.17\build\cef.redist.x64.props'))" />
<Error Condition="!Exists('..\packages\cef.redist.x86.89.0.17\build\cef.redist.x86.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\cef.redist.x86.89.0.17\build\cef.redist.x86.props'))" />
<Error Condition="!Exists('..\packages\cef.redist.3.1750.1738\build\cef.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\cef.redist.3.1750.1738\build\cef.redist.targets'))" />
<Error Condition="!Exists('..\packages\CefSharp.Common.33.0.2\build\CefSharp.Common.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\CefSharp.Common.33.0.2\build\CefSharp.Common.props'))" />
<Error Condition="!Exists('..\packages\CefSharp.Common.33.0.2\build\CefSharp.Common.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\CefSharp.Common.33.0.2\build\CefSharp.Common.targets'))" />
<Error Condition="!Exists('..\packages\CefSharp.Wpf.33.0.2\build\CefSharp.Wpf.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\CefSharp.Wpf.33.0.2\build\CefSharp.Wpf.props'))" />
</Target>

2 如果黄色感叹号已取消，那么不用执行下面命令。否则需要执行。

开程序包管理控制台
vs->工具->NuGet包管理器->程序包管理控制台
Update-Package –reinstall