C# 添加'；Xamarin.Forms'；到对象引用未设置为对象的实例。添加nuget包时出现错误
我使用的是C# 添加'；Xamarin.Forms'；到对象引用未设置为对象的实例。添加nuget包时出现错误,c#,xamarin,nuget,xamarin.forms,xamarin-studio,C#,Xamarin,Nuget,Xamarin.forms,Xamarin Studio,我使用的是Windows10，并且安装了VS2015，我最初尝试在其上运行Xamarin，但是由于1k的许可成本，我现在尝试使用Xamarin Studio，运气不太好。我确实创建了一个空白项目，并尝试构建它，但缺少了Xamarin.Formsreference，当我尝试通过nuget添加它时，我得到了以下结果： Could not add Xamarin.Forms. System.NullReferenceException: Object reference not set to an i
Windows10VS2015Xamarin.FormsCould not add Xamarin.Forms.
System.NullReferenceException: Object reference not set to an instance of an object.
at NuGet.NetPortableProfileTable.GetProfile(String profileName)
at NuGet.NetPortableProfile.Parse(String profileValue, Boolean treatOptionalFrameworksAsSupportedFrameworks)
at NuGet.VersionUtility.IsPortableLibraryCompatible(FrameworkName projectFrameworkName, FrameworkName packageTargetFrameworkName)
at NuGet.VersionUtility.IsCompatible(FrameworkName projectFrameworkName, FrameworkName packageTargetFrameworkName)
at NuGet.VersionUtility.<>c__DisplayClass19`1.<TryGetCompatibleItems>b__13(IGrouping`2 g)
at System.Linq.Enumerable.WhereListIterator`1.MoveNext()
at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__1.MoveNext()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
at NuGet.VersionUtility.TryGetCompatibleItems[T](FrameworkName projectFramework, IEnumerable`1 items, IEnumerable`1& compatibleItems)
at NuGet.ProjectSystemExtensions.GetCompatibleItemsCore[T](IProjectSystem projectSystem, IEnumerable`1 items)
at NuGet.ProjectManager.ExtractPackageFilesToProject(IPackage package)
at NuGet.ProjectManager.AddPackageReferenceToProject(IPackage package)
at NuGet.ProjectManager.Execute(PackageOperation operation)
at NuGet.ProjectManager.Execute(IPackage package, IPackageOperationResolver resolver)
at NuGet.ProjectManager.AddPackageReference(IPackage package, Boolean ignoreDependencies, Boolean allowPrereleaseVersions)
at NuGet.ProjectManager.AddPackageReference(String packageId, SemanticVersion version, Boolean ignoreDependencies, Boolean allowPrereleaseVersions)
at ICSharpCode.PackageManagement.SharpDevelopPackageManager.AddPackageReference(IPackage package, Boolean ignoreDependencies, Boolean allowPrereleaseVersions)
at ICSharpCode.PackageManagement.SharpDevelopPackageManager.InstallPackage(IPackage package, InstallPackageAction installAction)
at ICSharpCode.PackageManagement.PackageManagementProject.InstallPackage(IPackage package, InstallPackageAction installAction)
at ICSharpCode.PackageManagement.InstallPackageAction.ExecuteCore()
at ICSharpCode.PackageManagement.ProcessPackageAction.Execute()
at MonoDevelop.PackageManagement.BackgroundPackageActionRunner.RunActionsWithProgressMonitor(IProgressMonitor monitor, IList`1 packageActions)
at MonoDevelop.PackageManagement.BackgroundPackageActionRunner.RunActionsWithProgressMonitor(ProgressMonitorStatusMessage progressMessage, IList`1 installPackageActions)