Implementing File Download Functionality in ASP.NET: A Step-by-Step Guide

Learn how to implement file download functionality in your ASP.NET applications. This tutorial provides C# code examples demonstrating how to use the Response object to serve files for download, handling different file types and ensuring a smooth user experience.

File Download Functionality in ASP.NET

Implementing File Downloads using ASP.NET

ASP.NET provides built-in mechanisms for serving files to users for download. This typically involves setting appropriate HTTP headers in the server-side code to instruct the client's browser to download the file instead of displaying it directly in the browser. This tutorial shows how to implement file downloads in an ASP.NET application using the Response object.

Example: Downloading a Text File

This example demonstrates how to download a text file from the server. The C# code-behind handles the download process. Ensure that the file path specified in the code is correct and accessible to the web application.

ASPX Code (Default.aspx)


<%@ Page Title="Home Page" Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="FileDownloadExample._Default" %>
<form id="form1" runat="server">
    <asp:Button ID="Button1" runat="server" Text="Download File" OnClick="Button1_Click" />
    <asp:Label ID="Label1" runat="server"></asp:Label>
</form>

C# CodeBehind (Default.aspx.cs)


using System;
using System.IO;
using System.Web;
using System.Web.UI;
namespace FileDownloadExample
{
public partial class _Default : Page
{
    protected void Button1_Click(object sender, EventArgs e)
    {
        string filePath = "C:\\Users\\Admi\\Desktop\\abc.txt"; // Replace with your file path
        FileInfo file = new FileInfo(filePath);
        if (file.Exists)
        {
            Response.Clear();
            Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
            Response.AddHeader("Content-Length", file.Length.ToString());
            Response.ContentType = "text/plain"; // Set appropriate content type
            Response.TransmitFile(file.FullName);
            Response.End();
        }
        else
        {
            Label1.Text = "Requested file not found.";
        }
    }
}
}

Output

(A screenshot showing the browser's file download dialog would be included here.)