这很难追查，但问题归结为 .csproj 中的这个:

This was rather difficult to track down, but the problem boils down to this in your .csproj:

<Project Sdk="Microsoft.NET.Sdk">

在构建 Web 应用程序时，您需要改为引用 Web Sdk，如下所示:

As you are building a web application, you need to instead reference the Web Sdk, as follows:

<Project Sdk="Microsoft.NET.Sdk.Web">

我设法通过这个小改动重现并解决了您的问题.

I managed to reproduce and fix your issue with this small change.