.NET Core 中的构建命令错误（不知道这样的主机）

Question

我正在 .NET Core 中制作一个基本的控制台应用程序，当我尝试运行命令“dotnet build -c release -r win10-x64”时，我得到了这个：

Microsoft (R) Build Engine version 16.5.0+d4cbfca49 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Retrying 'FindPackagesByIdAsyncCore' for source 'http://packagesource/FindPackagesById()?id='Microsoft.NETCore.App.Runtime.win-x64'&semVerLevel=2.0.0'.
  No such host is known.
  Retrying 'FindPackagesByIdAsyncCore' for source 'http://packagesource/FindPackagesById()?id='Microsoft.WindowsDesktop.App.Runtime.win-x64'&semVerLevel=2.0.0'.
  No such host is known.
  Retrying 'FindPackagesByIdAsyncCore' for source 'http://packagesource/FindPackagesById()?id='Microsoft.AspNetCore.App.Runtime.win-x64'&semVerLevel=2.0.0'.
  No such host is known.
  Retrying 'FindPackagesByIdAsyncCore' for source 'http://packagesource/FindPackagesById()?id='Microsoft.NETCore.App.Runtime.win-x64'&semVerLevel=2.0.0'.
  No such host is known.
  Retrying 'FindPackagesByIdAsyncCore' for source 'http://packagesource/FindPackagesById()?id='Microsoft.WindowsDesktop.App.Runtime.win-x64'&semVerLevel=2.0.0'.
  No such host is known.
  Retrying 'FindPackagesByIdAsyncCore' for source 'http://packagesource/FindPackagesById()?id='Microsoft.AspNetCore.App.Runtime.win-x64'&semVerLevel=2.0.0'.
  No such host is known.
C:\Program Files\dotnet\sdk\3.1.201\NuGet.targets(124,5): error : Failed to retrieve information about 'Microsoft.NETCore.App.Runtime.win-x64' from remote source 'http://packagesourc
e/FindPackagesById()?id='Microsoft.NETCore.App.Runtime.win-x64'&semVerLevel=2.0.0'. [C:\Users\steve\PlatziCSharp\PlatziCSharp.csproj]
C:\Program Files\dotnet\sdk\3.1.201\NuGet.targets(124,5): error :   No such host is known. [C:\Users\steve\PlatziCSharp\PlatziCSharp.csproj]

Build FAILED.

C:\Program Files\dotnet\sdk\3.1.201\NuGet.targets(124,5): error : Failed to retrieve information about 'Microsoft.NETCore.App.Runtime.win-x64' from remote source 'http://packagesourc
e/FindPackagesById()?id='Microsoft.NETCore.App.Runtime.win-x64'&semVerLevel=2.0.0'. [C:\Users\steve\PlatziCSharp\PlatziCSharp.csproj]
C:\Program Files\dotnet\sdk\3.1.201\NuGet.targets(124,5): error :   No such host is known. [C:\Users\steve\PlatziCSharp\PlatziCSharp.csproj]
    0 Warning(s)
    1 Error(s)

Time Elapsed 00:00:08.30## Heading ##

它似乎缺少一些依赖项，我对此真的很陌生，我在网上找不到任何答案 任何人都可以帮助我如何安装我缺少的东西？ 过去我尝试做另一个 .NET Core 项目，但出现了同样的错误，我放弃了它，这太令人沮丧了。

Answer 1

1. 在 工具 > 选项... > NuGet 包管理器 > 包源， 按源添加包源https://api.nuget.org/v3/index.json
2. 在 tools > NuGet Package Manager > Package Manager Console 输入 dotnet restore 命令。

Answer 2

1. 在工具 > 选项... > NuGet 包管理器 > 包源中，添加 包源代码https://api.nuget.org/v3/index.json
2. 重新启动 Visual Studio 并重新加载您的解决方案/项目