How to add js and css files in ASP.net Core?

The better way to do it is to use: app.UseStaticFiles(); inside startup.cs before routing.

It might be a bit late to answer the question, but for the ones who come here via Google: I found that adding asp-append-version="true" worked for me, as all the other options given in the other answers were already provided in _Layout.cshtml.

I added the references inside the _Layout view, inside the <environment> tags:

<environment names="Development">
  <link rel="stylesheet" href="~/css/MyCss.css" />
</environment>

If anyone knows a better way I would welcome it