What is the equivalent of Server.MapPath in ASP.NET Core?

Question

I have this line in some code I want to copy into my controller, but the compiler complains that

The name \'Server\' does not exist in the current con

Answer 1

The accepted answer's suggestion is good enough in most scenarios, however - since it depends on Dependency Injection - is limited to Controllers and Views: in order to have a proper Server.MapPath replacement that can be accessed from non-singleton helper classes we can add the following line(s) of code at the end of the Configure() method of the app's Startup.cs file:

// setup app's root folders
AppDomain.CurrentDomain.SetData("ContentRootPath", env.ContentRootPath);
AppDomain.CurrentDomain.SetData("WebRootPath", env.WebRootPath);

This way we'll be able to retrieve them from within any class (including, yet not limiting to, Controllers and Views) in the following way:

var contentRootPath = (string)AppDomain.CurrentDomain.GetData("ContentRootPath");
var webRootPath = string)AppDomain.CurrentDomain.GetData("WebRootPath");

This can be further exploited to create a static helper method that will allow us to have the same functionality as the good old Server.MapPath:

public static class MyServer 
{
    public static string MapPath(string path)
    {
        return Path.Combine(
            (string)AppDomain.CurrentDomain.GetData("ContentRootPath"), 
            path);
    }
}

Which can be used it in the following way:

var docPath = MyServer.MapPath("App_Data/docs");

For additional info regarding this approach and a bit of background, take a look at this post on my blog.