C#: How to install System.Web

Question

I am using Visual Studio Code version 1.42 on my Ubuntu 18.04. I just successfully installed sudo dotnet add package Google.Apis.Drive.v3 via terminal but I can't find a way to install System.Web on my C# project.

I tried many different ways:

1) sudo dotnet add package Microsoft.AspNet.WebApi

2) sudo dotnet add package Microsoft.AspNet.Mvc -Version 5.2.7

3) sudo dotnet add package Microsoft.AspNet.Mvc

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;
//using System.Web;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;


namespace IHostingEnvironmentExample.Controllers
{
    public class HomeController : Controller
    {
        private IHostingEnvironment _env;
        public HomeController(IHostingEnvironment env)
        {
            _env = env;
        }
        public IActionResult Index()
        {
            var webRoot = _env.WebRootPath;
            var file = System.IO.Path.Combine(webRoot, "test.txt");
            System.IO.File.WriteAllText(file, "Hello World!");
            return View();
        }
    }
}


namespace WebApi2.Models
{
    public class GoogleDriveFilesRepository 
    {
       //defined scope.
        public static string[] Scopes = { DriveService.Scope.Drive };
        // Operations....

        //create Drive API service.
        public static DriveService GetService()
        {
             //Operations.... 

        public static List<GoogleDriveFiles> GetDriveFiles()
        {
            // Other operations....
        }

       //file Upload to the Google Drive.
        public static void FileUpload(HttpPostedFileBase file)
        {
            if (file != null && file.ContentLength > 0)
            {
                DriveService service = GetService();

                string path = Path.Combine(HttpContext.Current.Server.MapPath("~/GoogleDriveFiles"),
                Path.GetFileName(file.FileName));
                file.SaveAs(path);

                var FileMetaData = new Google.Apis.Drive.v3.Data.File();
                FileMetaData.Name = Path.GetFileName(file.FileName);
                FileMetaData.MimeType = MimeMapping.GetMimeMapping(path);

                FilesResource.CreateMediaUpload request;

                using (var stream = new System.IO.FileStream(path, System.IO.FileMode.Open))
                {
                    request = service.Files.Create(FileMetaData, stream, FileMetaData.MimeType);
                    request.Fields = "id";
                    request.Upload();
                }
            }
        }


        //Download file from Google Drive by fileId.
        public static string DownloadGoogleFile(string fileId)
        {
            DriveService service = GetService();

            string FolderPath = System.Web.HttpContext.Current.Server.MapPath("/GoogleDriveFiles/");
            FilesResource.GetRequest request = service.Files.Get(fileId);

            string FileName = request.Execute().Name;
            string FilePath = System.IO.Path.Combine(FolderPath, FileName);

            MemoryStream stream1 = new MemoryStream();

            request.MediaDownloader.ProgressChanged += (Google.Apis.Download.IDownloadProgress progress) =>
            {
                switch (progress.Status)
                {
                    case DownloadStatus.Downloading:
                        {
                            Console.WriteLine(progress.BytesDownloaded);
                            break;
                        }
                    case DownloadStatus.Completed:
                        {
                            Console.WriteLine("Download complete.");
                            SaveStream(stream1, FilePath);
                            break;
                        }
                    case DownloadStatus.Failed:
                        {
                            Console.WriteLine("Download failed.");
                            break;
                        }
                }
            };
            request.Download(stream1);
            return FilePath;
        }
    }
}

Post that I consulted to find a solution to this problem were this one, this, also this one. I came across this too which seemed to be related but no luck. Also this last one was useful, however I am confused about which type of package to install.

thanks for providing guidance on how to solve this problem.

Answer 1

As per the code you showed, you are trying to use System.Web.HttpContext.Current.Server.MapPath, which indeed does not exist in .NET Core.

There is no more HttpContext static usable in ASP.NET Core, along with System.Web entirely.

To replace the "Server.MapPath", you can follow some guidance here : https://www.mikesdotnetting.com/Article/302/server-mappath-equivalent-in-asp-net-core

Basically, you need to access a IHostingEnvironment env object, that ASP.NET Core will happily inject.

I'd recommend not using static methods to leverage the constructor dependency injection that is performed in controller constructor automatically.

Otherwise you can also call the dependency service to get the instance (all the details of how to use the dependency service is a bit out of scope here, but feel free to comment if this is not clear)

From this, you should be able to get the path of the server :

public class HomeController : Controller 
{ 
    private IHostingEnvironment _env;
    // Injection of IHostingEnvironment dependency through constructor
    public HomeController(IHostingEnvironment env)
    {
        _env = env;
    }

    public void MyMethod() 
    {
        // here you get your replacement of "Server.MapPath" :
        var serverPath = _env.WebRootPath;


        // ...
    }
}

See also this related Q&A : How to use IHostingEnvironment