Question

我在vs 2015中遇到了nuget包管理器的问题。像Unity这样的一些软件包安装没有问题。像EF这样的软件包在安装时遇到了问题。像Automapper这样的软件包有同样的问题，但是当我安装了这个软件包的另一个版本时，安装得很好。

这是输出：

System.NullReferenceException: Object reference not set to an instance of an object.


at NuGet.Protocol.Core.v3.GlobalPackagesFolderUtility.<AddPackageAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at NuGet.Protocol.Core.v3.DownloadResourceV3.<GetDownloadResourceResultAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.PackageManagement.PackageDownloader.<GetDownloadResourceResultAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__42.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at NuGet.PackageManagement.NuGetPackageManager.<ExecuteNuGetProjectActionsAsync>d__42.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.PackageManagement.UI.UIActionEngine.<ExecuteActionsAsync>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at NuGet.PackageManagement.UI.UIActionEngine.<PerformActionAsync>d__3.MoveNext()
========== Finished ==========

Answer 1

使用Visual Studio 2015中使用的新协议（版本3）nuget是一个常见问题。它使用多个nuget包，例如Microsoft.Owin 3.0.1。要解决这个问题，请访问：

C:\Users\<your user name>\AppData\Roaming\NuGet

编辑XML配置文件，评论协议3的行：

<!-- add key = "nuget.org" value = "https://api.nuget.org/v3/index.json" protocolVersion = "3" /-->
<add key = "nuget.org" value = "https://www.nuget.org/api/v2/" />

版本2的维护设置。保存并重新启动visual studio 2015.您现在应该可以毫无问题地恢复nuget包。

Answer 2

当我过去遇到Nuget问题时，这些是我已经完成的步骤：

1）使用Nuget包管理器删除项目

2）清理和构建（因为你有更长的引用，你会有错误 2）确保从packages.config中删除了包（如果没有，删除并重复步骤2）

3）确保.dll已从bin文件夹中删除（如果没有，请删除并重复步骤2）

4）重新添加包并重建。确保将包添加到packages.config（具有适当的版本）并将.dll添加回bin文件夹（具有适当的版本）。

Answer 3

我正在运行VS 2017，但在＆＃34; dotnet恢复＆＃34;期间，TFS构建服务器出现此错误。任务。问题是我们有一个内部本地文件共享，但是nuget.config有protocolVersion =＆＃34; 3＆＃34;对于那个条目。删除该属性后，构建成功。

Nuget - 未将对象引用设置为对象的实例

3 个答案: