Question

I want to provide dynamic download of files. These files can be generated on-the-fly on serverside so they are represented as byte[] and do not exist on disk. I want the user to fill in an ASP.NET form, hit the download button and return the file he/she wanted.

Here is how my code behind the ASP.NET form looks like:

public partial class DownloadService : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) {  }  protected void submitButtonClick(object sender, EventArgs e) {     if (EverythingIsOK())     {         byte[] binary = GenerateZipFile();          Response.Clear();         Response.ContentType = 'application/zip';         Response.ContentEncoding = System.Text.Encoding.UTF8;         Response.BinaryWrite(binary);         Response.End();     } } ... } 

I expected this piece of code just work. I clear the Respone, put in my generated zip file and bingo. However, this is not the case. I get the following message in the browser:

The XML page cannot be displayed Cannot view XML input using style sheet. Please correct the error and then click the Refresh button, or try again later. An invalid character was found in text content. Error processing resource ‘http://localhost:15900/mywebsite/DownloadS…

What am I doing wrong?

Answer 1

Here’s a minor modification you need to make:

Response.Clear(); Response.ContentType = 'application/x-zip-compressed'; Response.BinaryWrite(binary); Response.End();