How to make function make download file on asp.net core 2.2 Web API ?

Question

User696604810 posted

I work on project use .net core 2.2 visual studio 2017 Web API 

i Need to make function download file 

Give function path and download file as below 

I need to make function do download file on .net core 2.2 as 

        public void DownloadOutPut(string path)
        {
            try
            {


                if (path != "")
                {


                    System.IO.FileInfo file = new System.IO.FileInfo(path);
                    if (file.Exists)
                    {

                        Response.Clear();
                        Response.ContentType = "application/octet-stream";
                        Response.AppendHeader("Content-Disposition", "attachment;filename = " + file.Name + "");
                        Response.TransmitFile(path);


                    }

                    Response.End();
                }
            }
            catch (Exception ex)
            {

                throw;
            }
        }

above done on asp.net  web form I need to  do function similar to it but on .net core 2.2 

so How to do it please ?

Answer 1

User1312693872 posted

Hi, ahmedbarbary

Based on your former post, I added a download function , you can check this demo:

Controller:

        private readonly IFileProvider fileProvider;             

        public HomeController(IFileProvider fileProvider)
        {
            this.fileProvider = fileProvider;
        }

        public IActionResult Index()
        {
            return View();
        }
        [HttpPost]
        public IActionResult Upload(IFormFile file)
        {
                var DisplayFileName = Request.Form.Files[0].FileName;
                string DirectoryCreate = "FilesHere";
                if (!Directory.Exists(DirectoryCreate))
                {
                    Directory.CreateDirectory(DirectoryCreate);

                }
                if (DisplayFileName.Length > 0)
                {
                    var dbPath = Path.Combine(DirectoryCreate, DisplayFileName);
                    using (var stream = new FileStream(dbPath, FileMode.Create))
                    {
                        Request.Form.Files[0].CopyTo(stream);
                    }
                return RedirectToAction("Files");
                }
                else
                {
                    return BadRequest();
                }
        }

        public IActionResult Files() //save files and show it in this demo
        {
            var model = new FilesViewModel();
            foreach (var item in this.fileProvider.GetDirectoryContents(""))
            {
                model.Files.Add(
                    new FileDetails { Name = item.Name, Path = item.PhysicalPath });
            }
            return View(model);
        }

        public async Task<IActionResult> Download(string filename)  //download function
        {
            if (filename == null)
                return Content("filename not present");

            var path = Path.Combine(
                           Directory.GetCurrentDirectory(),
                           "FilesHere", filename);  //get the file

            var memory = new MemoryStream();
            using (var stream = new FileStream(path, FileMode.Open))
            {
                await stream.CopyToAsync(memory);
            }
            memory.Position = 0;
            return File(memory, GetContentType(path), Path.GetFileName(path));
        }

        private string GetContentType(string path)
        {
            var types = GetMimeTypes();
            var ext = Path.GetExtension(path).ToLowerInvariant();
            return types[ext];
        }
        private Dictionary<string, string> GetMimeTypes()
        {
            return new Dictionary<string, string>
            {
                {".txt", "text/plain"},
                {".pdf", "application/pdf"},
                {".doc", "application/vnd.ms-word"},
                {".docx", "application/vnd.ms-word"},
                {".xls", "application/vnd.ms-excel"},
                {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
                {".png", "image/png"},
                {".jpg", "image/jpeg"},
                {".jpeg", "image/jpeg"},
                {".gif", "image/gif"},
                {".csv", "text/csv"}
            };
        }

Index View:

@model MyModel

<form method="post" enctype="multipart/form-data" asp-action="Upload">
    <input type="file" asp-for="Upload"/>
    <input type="submit" value="submit"/>
</form>

'Files' view:

@model FilesViewModel

@foreach (var item in Model.Files)
{
<li>
    <a asp-action="Download"
       asp-route-filename="@item.Name">
        @item.Name
    </a>
</li>}

FilesViewModel:

public class FilesViewModel
    {
        public List<FileDetails> Files { get; set; }
            = new List<FileDetails>();
    }
    public class FileDetails
    {
        public string Name { get; set; }
        public string Path { get; set; }
    }

MyModel:

public class MyModel
    {
        public IFormFile Upload { get; set; }
    }

And you should add the following code to ConfigureServices()

services.AddSingleton<IFileProvider>(new PhysicalFileProvider(
                Path.Combine(Directory.GetCurrentDirectory(), "FilesHere")));

Result:

Best Regards,

Jerry Cai

Answer 2

User1312693872 posted

Hi, ahmedbarbary

Have you solved your problem, do you have any problems when using my code, welcome to ask.

Best Regards,

Jerry Cai