VS 2019 没有为新项目构建解决方案

Question

我昨天更新了 VS 2019，今天我正在尝试为 asp.net 核心 Web 应用程序创建新项目，项目已创建，但是当我构建解决方案或尝试运行解决方案时，我不断收到以下错误。

Error   MSB4018 The "ResolveTargetingPackAssets" task failed unexpectedly.

完整的错误详情

Severity    Code    Description Project File    Line    Suppression State
Error   MSB4018 The "ResolveTargetingPackAssets" task failed unexpectedly.
System.IO.FileNotFoundException: Could not find file 'C:\Program Files\dotnet\packs\Microsoft.AspNetCore.App.Ref\3.1.2\data\FrameworkList.xml'.
File name: 'C:\Program Files\dotnet\packs\Microsoft.AspNetCore.App.Ref\3.1.2\data\FrameworkList.xml'
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize)
   at System.Xml.XmlDownloadManager.GetStream(Uri uri, ICredentials credentials, IWebProxy proxy, RequestCachePolicy cachePolicy)
   at System.Xml.XmlUrlResolver.GetEntity(Uri absoluteUri, String role, Type ofObjectToReturn)
   at System.Xml.XmlTextReaderImpl.FinishInitUriString()
   at System.Xml.XmlTextReaderImpl..ctor(String uriStr, XmlReaderSettings settings, XmlParserContext context, XmlResolver uriResolver)
   at System.Xml.XmlReaderSettings.CreateReader(String inputUri, XmlParserContext inputContext)
   at System.Xml.XmlReader.Create(String inputUri, XmlReaderSettings settings, XmlParserContext inputContext)
   at System.Xml.Linq.XDocument.Load(String uri, LoadOptions options)
   at Microsoft.NET.Build.Tasks.ResolveTargetingPackAssets.AddReferencesFromFrameworkList(String frameworkListPath, String targetingPackDllFolder, ITaskItem targetingPack, List`1 referenceItems)
   at Microsoft.NET.Build.Tasks.ResolveTargetingPackAssets.ExecuteCore()
   at Microsoft.NET.Build.Tasks.TaskBase.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext() WebApplicationLoginTest C:\Program Files\dotnet\sdk\3.1.300\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.FrameworkReferenceResolution.targets   283 

我能够运行的旧项目，问题似乎只与我创建的新项目有关。

这可能是因为我昨天做了 VS 更新

Answer 1

我在安装新版 Visual Studio 2019 (16.6.0) 后遇到了同样的问题。

就我而言，我通过从 Microsoft 页面重新安装 ASP.net core 3.1 解决了这个问题。

例如，在以下链接中：this