ASP.NET Core：HtmlHelper 扩展（迁移问题）

Question

I am trying to update some code in a old MVC-project (.NET Framework 4.5.2) to work with .NET Core 2.2. I got stuck on a extension method of HtmlHelper that is generating a link inside a string.

public static HtmlString GetMenu(this HtmlHelper htmlHelper)
{
   htmlString += string.Format("<li{0}>{1}</li>",
            controller == "Examples" ? " class=\"selected\"" : "",
            htmlHelper.ActionLink("Examples", "Index", "Examples")
        );
}

The HtmlHelper class are found inside the Microsoft.AspNetCore.Mvc.ViewFeatures in .NET Core, but the method ActionLink want more information. Instead of 3 arguments as in the old project, it now wants 8 arguments, and two of these are protocol and hostname. But I am not sure how to get hostname and protocol in a static class, without accessing the HttpContext.

Answer 1

In ASP.NET Core, the class that was previously called HtmlHelper has now been replaced by the interface IHtmlHelper .

This means that all the link extensions ( HtmlHelperLinkExtensions ) have switched to the interface as well.

https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.mvc.rendering.htmlhelperlinkextensions?view=aspnetcore-2.2