How can i download a file on a button's onClick event in C#?

Question

Im trying to download a file on my button's onClick event in C# anyone got any info on this?

Ok so to the people who wanted me to be a litle more specific im working in visual studio 2015 windows forms c#.

Answer 1

If you are using MVC then you can try the following code it is working for me :

#region Download File ==>
        public ActionResult downloadfile(string Filename, string MIMEType)
        {
            try
            {
                string file_name = "/Files/EvidenceUploads/" + Filename;
                string contentType = "";
                //Get the physical path to the file.
                string FilePath = Server.MapPath(file_name);

                string fileExt = Path.GetExtension(file_name);

                contentType = MIMEType;

                //Set the appropriate ContentType.
                Response.ContentType = contentType;
                Response.AppendHeader("content-disposition", "attachment; filename=" + (new FileInfo(file_name)).Name);

                //Write the file directly to the HTTP content output stream.
                Response.WriteFile(FilePath);
                Response.End();
                return View(FilePath);
            }
            catch
            {
                Response.End();
                return View();
                //To Do
            }

        }
        #endregion

If you are not using MVC please refer following code:

#region Download File ==>
        public void downloadfile(string Filename, string MIMEType)
        {
            try
            {
                string file_name = "/Files/EvidenceUploads/" + Filename;
                string contentType = "";
                //Get the physical path to the file.
                string FilePath = Server.MapPath(file_name);

                string fileExt = Path.GetExtension(file_name);

                contentType = MIMEType;

                //Set the appropriate ContentType.
                Response.ContentType = contentType;
                Response.AppendHeader("content-disposition", "attachment; filename=" + (new FileInfo(file_name)).Name);

                //Write the file directly to the HTTP content output stream.
                Response.WriteFile(FilePath);
                Response.End();

            }
            catch
            {
                Response.End();

                //To Do
            }

        }
        #endregion

Hope its help to you.

Answer 2

First, question is too broad (Not specified is that desktop or Web application) . Lets suggest that you mean Winforms, then quick answer is DownloadFileAsync ( Async in order to keep UI interactive for user):

  private void Download_Click(object sender, RoutedEventArgs e)
   {
      using (WebClient wc = new WebClient())
      {
         wc.DownloadProgressChanged += wc_DownloadProgressChanged;
         wc.DownloadFileAsync(new System.Uri("http://url"),
          "Result location");
      }
   }

It`sa good idea to have a progress bar:

   void wc_DownloadProgressChanged(object sender,  DownloadProgressChangedEventArgs e)
   {
      progressBar.Value = e.ProgressPercentage;
   }

Answer 3

Using ASP.NET MVC I used the following within a controller to return a file from the content/Audiofile folder.

 /// <summary>
 /// The download action returns the file as a File download.
 /// </summary>
 /// <param name="filename"></param>
 /// <returns></returns>
 [AllowAnonymous]
 public FilePathResult Download(String filename)
 {
    String myfile = Path.Combine(HttpContext.Server.MapPath("~/Content/audiofiles/"), filename);
    return File(myfile, System.Net.Mime.MediaTypeNames.Application.Octet, filename);
 }