Get wwwroot folder path from ASP.NET 5 controller VS 2015

Question

Sorry for a noob question, but it seems I can't get Server.MapPath from Controller. I need to output json file list from images folder at wwwroot. They are is at wwwroot/images. How can I get a reliable wwwroot path?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNet.Mvc;
using www.Classes;
using System.Web;

namespace www.Controllers
{
    [Route("api/[controller]")]
    public class ProductsController : Controller
    {
        [HttpGet]
        public IEnumerable<string> Get()
        {
            FolderScanner scanner = new FolderScanner(Server.MapPath("/"));
            return scanner.scan();
        }
    }
}

Server.MapPath seems not available from System.Web namespace.

Project is using ASP.NET 5 and dotNET 4.6 Framework

Answer 1

You will need to inject IWebHostEnvironment into your class to have access to the ApplicationBasePath property value: Read about Dependency Injection. After successfully injecting the dependency, the wwwroot path should be available to you. For example:

private readonly IWebHostEnvironment _appEnvironment;

public ProductsController(IWebHostEnvironment appEnvironment)
{
   _appEnvironment = appEnvironment;
}

Usage:

 [HttpGet]
 public IEnumerable<string> Get()
 {
    FolderScanner scanner = new FolderScanner(_appEnvironment.WebRootPath);
    return scanner.scan();
 }

Edit: IHostingEnvironment has been replaced by IWebHostEnvironment in later versions of asp.net.

Answer 2

I know this has already been answered, but it has given me different results depending on my hosting environment (IIS Express vs IIS). The following approach seems to work for all hosting environments nicely if you want to get your wwwroot path (see this GitHub issue).

For example

private readonly IHostingEnvironment _hostEnvironment;

public ProductsController(IHostingEnvironment hostEnvironment)
{
   _hostEnvironment = hostEnvironment;
}

[HttpGet]
public IEnumerable<string> Get()
{
   FolderScanner scanner = new FolderScanner(_hostEnvironment.WebRootPath);
   return scanner.scan();
}

Answer 3

For those who deploy to Azure and come into this error. What I did was a work around for it, I haven't tried to figure out why environment of Azure is different than local IIS. Here is my work around:

if (string.IsNullOrWhiteSpace(_environment.WebRootPath))
{
   _environment.WebRootPath = System.IO.Path.Combine(Directory.GetCurrentDirectory(), "wwwroot");
}

Of course you will need:

private IHostingEnvironment _environment;

public OnboardingController(IHostingEnvironment environment)
{
     _environment = environment;
}

Answer 4

There is another way to implement this right from startup. It is not exact solution to this case per se, but I modified it to suit my need. We need a singleton for this. This is a startup class with environment injection.

namespace www
{
    public class Startup
    {
        private IHostingEnvironment _env;

        public Startup(IHostingEnvironment env)
        {
            _env = env;
            Environment.rootPath = env.WebRootPath;
        }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
        }

        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            app.UseStaticFiles();
            app.UseMvc();
        }
    }
}

The environment variables I was looking for is there, IHOstingEnvironment. But for my purpose, I need to make Environment class like this to easily access all environment items from all project. This singleton will provide data to configuration, environment, and many other thing. But for this thread, I would just put one rootPath property.

namespace www.Utilities
{
    public class Environment
    {
        private static Environment instance;
        private static String _rootPath;

        private Environment() { }

        public static Environment Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = new Environment();
                }
                return instance;
            }
        }

        public static string rootPath
        {
            set
            {
                _rootPath = value;
            }
            get
            {
                return _rootPath;
            }
        }    
    }
}

As I have accepted Oluwafemi's answers, I'll keep it that way, since he led me to this. But I think this is the better way to access environment variables throughout the project