ASP.NET Core MVC Web应用程序中的HTML编码问题

Question

I just started at a new job as a senior .NET developer, and have run into a very puzzling issue with the package System.Text.Encodings.Web.

The project is in .NET Framework 4.6.1

The package is showing in the NUGET PACKAGE MANAGER as Installed version 4.5.0, however, the using statement in a .CS file that is trying to use the HtmlEncoder is showing an error with the error text "The type or namespace 'Encodings' does not exist in the namespace 'System.Text'. Are you missing an assembly reference?"

It also says after trying to build, another error, "The type HtmlEncoder is defined in an assembly that is not referenced, You must add a reference to assembly 'System.Text.Encodings.Web, version=4.0.3, Culture=neutral, and then a public key token after that."

I tried several different things but none of them worked.

Answer 1

In my case, I had the same problem in a NUnitTest project which referenced the main project (both netcorapp2.1).

I have solved the problem by copying the below Package References from the main project into the test project (.csproj files):

<PackageReference Include="Microsoft.AspNetCore.App" />
<PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.1.2" PrivateAssets="All" />