how do you map path in razor for .net core 2.0 mvc?

Question

I am trying to convert a layout page to .net core 2.0. unfortunately in razor Server.MapPath is no longer available.

I am trying to find the equivalent in a .cshtml page for

<div style="height: 0px; width: 0px; position: absolute; visibility: hidden;">
        @Html.Raw(System.IO.File.ReadAllText(Server.MapPath("~/Content/images/svg-defs.svg")))
    </div>

Answer 1

In ASP.NET Core, you can use the IHostingEnvironment service to gain access to certain paths of the webapp.

There are two interesting properties on this object:

• ContentRootPath: the path to the applications base path (where you would usually find appsettings.json, Program.cs, etc
• WebRootPath: the path to the /wwwroot directory, which is what you are looking for.

To get access to the IHostingEnvironment service, simply inject it in the constructor of your controller and hold on it with a field.

public class HomeController : Controller
{
    private IHostingEnvironment _env;

    public HomeController(IHostingEnvironment env)
    {
        _env = env;   
    }
}

Now, in an action method of this Controller, you can now construct the physical path to a file using System.IO.Path.Combine and the WebRootPath property.

public IActionResult Index()
{
    ViewBag.FilePath = Path.Combine(_env.WebRootPath, @"Content\images\svg-defs.svg");
    return View();
}

In this example I added the resulting path to the ViewBag to easily display it in the Index view:

<h2>Index View</h2>

<p>Filepath: @ViewBag.FilePath</p>

This would print something along the lines of C:\MySite\wwwroot\Content\images\svg-defs.svg