Progress Indicator With FileUpload control

Question

I have a web page which I want people to be able to upload content to. (There will only be a small number of people using it, as it is access restricted, so I'm not too worried about any DOS type attacks.)

I'm using a fileUpload control to do this:

protected void Button1_Click(object sender, EventArgs e)
    {
        if (fileUploader.HasFile)
        try {
          fileUploader.SaveAs(Server.MapPath("Uploads\\") + fileUploader.FileName);
          errorMessage.Text = "File name: " +
               fileUploader.PostedFile.FileName + "<br>" +
               fileUploader.PostedFile.ContentLength + " kb<br>";
        }
        catch (Exception ex) {
          errorMessage.Text = "ERROR: " + ex.Message.ToString();
        }
        else
        {
           errorMessage.Text = "You have not specified a file.";
        } 
    }

The files can be up to 50MB (I have changed the web.config to allow this). The problem I have is that with large files the user can't see the progress of the upload.

I want to know how I can display the progress on the page so the user can see something is happening. Not fussed about anything fancy - just something like:

bytes uploaded / total bytes

would be fine. I can get the total bytes using postedFile.ContentLength, but don't know how to get the bytes uploaded.

Also - am I able to refresh the screen as the upload is taking place?

Cheers,

Ben

Answer 1

This answer is not specific to ASP...

A file upload is typically done by making an HTTP POST request with Content-type: multipart/form-data . This includes the file body in one of the parts of the request body.

So within a given browser tab, there can only be one page loading at a given time. The short answer is, unless you get really fancy with iframes (one for status, one for upload), you will not be able to show the status.

However , if you use Flash, you can. http://www.uploadify.com/ is a great little front-end plugin (for jQuery) which allows the user to select multiple files, and uploads them all, showing the status along the way. I just plugged it into a site that limits uploads to 64M. Works awesome.

Answer 2

Your implementation is a synchronous operation which does not 'feedback' to the user about the file upload progress.

There are quite a few alternatives and 3rd party components, you might want to google them.

Here's one to start with: ASP.NET File Upload with Real-Time Progress Bar

Answer 3

I have used a couple of commercial components to do this:

Telerik and AjaxUPloader