Question

I have a web application allowing to download files from the server. Documents might be Office files (.docx, pptx, .xslx) or Pdf.

The logic is quite simple: on click from client side a web service is called and calls an aspx page (Print.aspx) passing the needed parameters. Print page calls a web service to retrieve the selected documents binaries and write them in the response:

protected void Page_Load(object sender, EventArgs e)
    {
        string fileName = Request.QueryString["fname"];
        if (string.IsNullOrEmpty(documentID) == false)
        {
            byte[] document = GetPhysicalFile(documentID); //Get the binaries
            showDownloadedDoc(document, fileName);
        }
    }

private void showDownloadedDoc(byte[] document, string fileName)
{
Response.Clear();
Response.ContentType = contentType;

Response.AppendHeader("content-disposition", string.Format("attachment; filename=\"{0}\"", fileName));
Response.BufferOutput = false;
Response.BinaryWrite(document);
Response.Close();

 }

Pdf documents are opened in the Print.aspx page and the aspx page is loaded only once. For Office files, the Page_Load() method is invoked 3 times.

After the first time the dialog for Open/Save the document is opened and if “Open” ic clicked, then the Page_Load is called twice and after that the document is finally oepend in MS Word, for instance.

Is there a way I can prevent to have multiple page loads for opening these documents? I would like to avoid having to save the file on Server Side and Redirect to that URL, since a file for each access would be created.

Answer 1

Here is an example with a GenericHandler

public void ProcessRequest(HttpContext context)
{

  string filePath; // get from somewhere
  string contentType; // get from somewhere

  FileInfo fileInfo = new FileInfo(filePath);

  context.Response.Clear();
  context.Response.ContentType = contentType;
  context.Response.AddHeader("content-disposition", "attachment; filename=" + Path.GetFilename(filePath));
  context.Response.AddHeader("Content-Length", fileInfo.Length.ToString());
  context.Response.TransmitFile(filePath);
}