In this article I will explain with an example, how to use FileResult in .Net Core.
This article will illustrate how to download files using FileResult class in ASP.Net Core MVC.
FileStreamResult class is a wrapper class of FileStreamResult, FileContentResult and FilePathResult classes.
Note: For beginners in ASP.Net MVC Core, please refer my article ASP.Net MVC Core Hello World Tutorial with Sample Program example.
 
 
Folder (Directory) Location
The Folder (Directory) is located within the Project inside the wwwroot folder. Below is the screenshot of the Solution Explorer window where you can see the Folder (Directory) i.e. Files and it containing three files.
FileResult .Net Core Example: Using FileResult in ASP.Net Core MVC
 
 
Model
Following is a Model class named FileModel with one property i.e. FileName.
public class FileModel
{
    public string FileName { get; set; }
}
 
 
Namespaces
You will need to import the following namespaces.
using System.IO;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Hosting;
 
 
Controller
The Controller consists of two Action methods.
Action method for handling File Display operation
Inside this Action method, the list of all files in the Files Folder (Directory) (present in the wwwroot Folder) is fetched using the IHostingEnvironment interface into a String Array using the GetFiles method of the Directory class.
Note: For more details about IHostingEnvironment interface, please refer Using IHostingEnvironment in ASP.Net Core.
 
Later, the values of the Array are copied to a Generic List collection consisting objects of FileModel class and then returned to the View.
 
Action method for handling File Download operation
This action method handles the File Download operation and when the ActionLink is clicked, the name of the File to be downloaded is sent to this method.
Note: The following Action method performs File Download and hence the return type is set to FileResult.
 
First, the File is read as Binary Data into a Byte Array object using the ReadAllBytes method of the File class.
And then the Byte Array object is sent for download using the File function.
public class HomeController : Controller
{
    private IHostingEnvironment Environment;
 
    public HomeController(IHostingEnvironment _environment)
    {
        Environment = _environment;
    }
 
    public IActionResult Index()
    {
        //Fetch all files in the Folder (Directory).
        string[] filePaths = Directory.GetFiles(Path.Combine(this.Environment.WebRootPath, "Files/"));
 
        //Copy File names to Model collection.
        List<FileModel> files = new List<FileModel>();
        foreach (string filePath in filePaths)
        {
            files.Add(new FileModel { FileName = Path.GetFileName(filePath) });
        }
 
        return View(files);
    }
 
    public FileResult DownloadFile(string fileName)
    {
        //Build the File Path.
        string path = Path.Combine(this.Environment.WebRootPath, "Files/") + fileName;
 
        //Read the File data into Byte Array.
        byte[] bytes = System.IO.File.ReadAllBytes(path);
 
        //Send the File to Download.
        return File(bytes, "application/octet-stream", fileName);
    }
}
 
 
View
Inside the View, the FileModel class is declared as List which specifies that it will be available as a Collection.
Displaying the Files
For displaying the files, an HTML Table is used. A loop will be executed over the Model which will generate the HTML Table rows with the File records.
 
Downloading the File
The HTML Table contains an ActionLink for downloading the File.
When the Download link is clicked, the ActionLink calls the DownloadFile Action method and the File is downloaded.
@using MVC_Core_File_Download.Models
@model List<FileModel>
 
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width"/>
    <title>Index</title>
</head>
<body>
    <table>
        <tr>
            <th>File Name</th>
            <th></th>
        </tr>
        @foreach (FileModel file in Model)
        {
            <tr>
                <td>@file.FileName</td>
                <td>@Html.ActionLink("Download", "DownloadFile", new { fileName = file.FileName })</td>
            </tr>
        }
    </table>
</body>
</html>
 
 
Screenshot
FileResult .Net Core Example: Using FileResult in ASP.Net Core MVC
 
 
Downloads
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