How to download multiple files in ASP.NET Core MVC

This article explains how to download multiple files using ASP.NET Core MVC. First, create a table to store file information, such as filename and source path.

Here is the following step-by-step guide to download multiple files in ASP.NET Core MVC:

Table of Contents

Create an Asp.NET Core MVC Project

Assuming you have Visual Studio 2019 or Visual Studio 2022 installed, follow these steps to create a new ASP.NET Core Project.

Open the visual studio (IDE).
Click on the “Create new project” option.
Choose “ASP.NET Core Web Application” from the list of available templates.
Click the Next button.
Then configure a new project, and specify the name and location of your project.
Click the “Next” button.
Then select .Net Core as the runtime and choose the version from the dropdown list at the top.
Make sure to uncheck the checkboxes for “Enable Docker Support” and “Configure for HTTPS” since we won’t be using authentication.
Click the “Create” button

Create a Model

namespace WebApplication_Download_Files.Models
{
    public class FileAssets
    {
        public Guid Id { get; set; }
        public string Filename { get; set; } = null;
        public string FileUrls { get; set; } = null;

        public FileAssets()
        {
            Id = Guid.NewGuid();
        }
    }
}

Configure Database Connection

Open the Program.cs file and add the following code snippet.

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.SqlServer;
using Microsoft.Extensions.Configuration;
using WebApplication_Download_Files.Models;


var builder = WebApplication.CreateBuilder(args);

//Connection string
// "connectionstr": //"Server=localhost;Database=inventoryDb;Encrypt=False;Trusted_Connection=True;"

builder.Services.AddDbContext<AppDbContext>(opt=> opt.UseSqlServer(builder.Configuration.GetConnectionString("connectionstr")));
// Add services to the container.
builder.Services.AddControllersWithViews();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
}
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

Migration

Run the following command in the package manager console.

add-migration 'Init-create'
update-database

Create Controller

Open the HomeController.cs file. Create a new method named “downloadAll”

using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Diagnostics;
using System.Text;
using WebApplication_Download_Files.Models;
using Microsoft.AspNetCore.Hosting;
using System.IO.Compression;

namespace WebApplication_Download_Files.Controllers
{
    public class HomeController : Controller
    {
        
        private readonly AppDbContext _context;
        private readonly IWebHostEnvironment _env;

        public HomeController(AppDbContext context, IWebHostEnvironment env)
        {
           
            _context = context;
            _env = env;
         
        }

        public async Task<IActionResult> Index()
        {
            return _context.FileAssets != null ?
                        View(await _context.FileAssets.ToListAsync()) :
                        Problem("Entity set 'AppDbContext.FileAssets'  is null.");

        }

        public IActionResult downloadAll()
        {
            var ZipFile = $"docFile-{DateTime.Now.ToString("yyyy_MM-dd-HH_mm_ss")}.zip";

            using (var memorystream = new MemoryStream())
            {
                using(var archieve = new ZipArchive(memorystream,ZipArchiveMode.Create,true))
                {
                    _context.FileAssets.ToList().ForEach(files=>
                    {
                        var zipentry = archieve.CreateEntry(files.Filename);
                        var stringpath = Path.Combine(this._env.WebRootPath +  files.FileUrls);
                        byte[] bytes = System.IO.File.ReadAllBytes(stringpath);
                        using (var filems = new MemoryStream(bytes))
                            using(var openstream = zipentry.Open())
                        {
                            filems.CopyTo(openstream);
                        }

                    });
                }
                return File(memorystream.ToArray(), "application/zip", ZipFile);
            }
        }
    }
}

Create View

Open the Index.cshtml file and update the following code:

@model IEnumerable<WebApplication_Download_Files.Models.FileAssets>
@{
    ViewData["Title"] = "Home Page";
}

<div class="text-center">
    <h1 class="display-4">File List to Download</h1>


    <table class="table">
        <thead>
            <tr>
                <th>
                    @Html.DisplayNameFor(model => model.Filename)
                </th>
                <th>
                    Action
                </th>
                <th></th>
            </tr>
        </thead>
        <tbody>
            @foreach (var item in Model)
            {
                <tr>
                    <td>
                        @Html.DisplayFor(modelItem => item.Filename)
                    </td>
                    
                    <td>
                        @Html.ActionLink("Download File","download",new{Filename = item.FileUrls  } )                        
                    </td>

                </tr>
            }
        </tbody>
    </table>
    <a asp-controller="Home" asp-action="downloadAll">Download All</a> 

</div>

output: