xamarin git pull nuget 包错误

Question

我是 Xamarin android 开发的新手。我从 git 中提取代码。之后，我在 Visual Studio 中打开了我的解决方案。我清理了解决方案 - 现在很好。然后我尝试构建它显示错误的解决方案。>Restoring NuGet packages...To prevent NuGet from restoring packages during build, open the Visual Studio Options dialog, click on the Package Manager node and uncheck 'Allow NuGet to download missing packages during build.'NuGet Package restore failed for project app: Unable to find version '2.0.0' of package 'FastAndroidCamera'.  C:\Program Files (x86)\Microsoft SDKs\NuGetPackages\: Package 'FastAndroidCamera.2.0.0' is not found on source 'C:\Program Files (x86)\Microsoft SDKs\NuGetPackages\'.  https://api.nuget.org/v3/index.json: Unable to load the service index for source https://api.nuget.org/v3/index.json.  An error occurred while sending the request.  The remote name could not be resolved: 'api.nuget.org'1>------ Rebuild All started: Project: app, Configuration: Debug Any CPU ------1>D:\PRANAV\TOLL\GIT\MobileApp-12-06-2018\MobileApp\app\app.csproj(467,5): error : 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 ..\packages\Xamarin.Build.Download.0.4.3\build\Xamarin.Build.Download.props.========== Rebuild All: 0 succeeded, 1 failed, 0 skipped ==========\这是我得到的错误。所以伙计们你能弄清楚我在哪里做错了吗？