所以我一直在尝试添加对一些 .dll 文件的本地引用。有一次，出于好奇，我将 Build 更改为支持 .Net 标准平台。然后，这不包括 Xamarin.Forms 作为我需要的参考。于是我又退了回去。但是，现在当它尝试将 Xamarin.Forms 还原为参考时，它会尝试查找我包含的参考并失败。由于此失败，它不仅没有包含我的自定义引用，而且还没有包含 Xamarin.Forms。
Running non-parallel restore.
Reading project file /Users/*****/Projects/Goal_1.02/Goal_1.02/Goal_1.02.csproj.
Restoring packages for /Users/*****/Projects/Goal_1.02/Goal_1.02/project.json...
Restoring packages for .NETPortable,Version=v4.5,Profile=Profile111...
GET https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms'
GET https://api.nuget.org/v3-flatcontainer/xamarin.forms/index.json
NotFound https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms' 295ms
Retrying 'FindPackagesByIdAsyncCore' for source 'https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms''.
404 (Not Found)
GET https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms'
NotFound https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms' 250ms
Retrying 'FindPackagesByIdAsyncCore' for source 'https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms''.
404 (Not Found)
GET https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms'
OK https://api.nuget.org/v3-flatcontainer/xamarin.forms/index.json 313ms
GET https://api.nuget.org/v3-flatcontainer/xamarin.forms/2.3.4.231/xamarin.forms.2.3.4.231.nupkg
OK https://api.nuget.org/v3-flatcontainer/xamarin.forms/2.3.4.231/xamarin.forms.2.3.4.231.nupkg 124ms
NotFound https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms' 342ms
Failed to retrieve information about 'Xamarin.Forms' from remote source 'https://github.com/gstreamer-sharp/gstreamer-sharp.git/FindPackagesById()?id='Xamarin.Forms''.