Question

I have an ASP.NET Web Form (C#) that users fill out, it has a couple of drop down lists that cause post backs and some validation that causes post backs. I also use a couple of different update panels. One panel is visible for user input and the other panel appears after the user clicks submit and the data is added to the database. The confirmation panel (the last panel) also displays a confirmation number to the user.

After the last panel displays, I would like to prevent the page from reloading when the user presses F5 or refresh. The reason is, I don’t want the user to accidentally click refresh or F5 and lose the confirmation number and message. When the user presses F5, the browser interprets it as wanting to load a new page and at that point the session is cleared (as indicated in code below).

My first thought was to reprint the message and confirmation number and make sure that the panel holding it stayed visible. I was going to do this in the else section of the code below – but since there are multiple postbacks and they all trigger the page load, that doesn’t work, unless there is someway to determine if the postback is the result of a form element or the f5 key.

protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            if (!IsPostBack)
            {
                Session.Clear();
                GetList();
            }
        }
        catch (Exception ex)
        {
            //Do something();
        }
    }

I’ve seen a few different posts that recommend using Javascript, but I am avoiding that if possible, in the remote chance that someone has javascript turned off.

Here is the flow of the program:
User opens form, fills in fields in the contactpanel and the clicks submit. The fields are validated using ASP.NET server validation controls and if everything is good, the data is sent to the database and a confirmation number is returned. Finally, the contactpanel is set to visibility=false and the confirmationpanel is set to visibility=true.

Hope this helps. Appreciate any suggestions.

Thanks,

Answer 1

Move your content that’s on the final screen (the confirmation) to an entirely new page. Whatever data is saved to get to that confirmation should go in some type of data storage (like a database), and then whatever ID or variables the visitor needs to pull that information should go in a Session var. This way when the user refreshes the page, they will still see the content as you intend. It’s pretty much how we had to do all forms back in the day anyway.

For instance:

~/form_page.aspx
- User lands
- Fills in information
- Post backs save data as the user progresses
- Save all data collected to a resource such as a database
- Save an ID to access that information to a Session variable
- Redirect user to...

~/form_thankyou.aspx
- On load, get the Session variable needed to pull the information
- Retrieve information from the resource
- Display results to user

(That’s not actual code, I was just having trouble with the formatting.)

Using this technique will also make it easier on your SEO/Metrics team to track conversions (even though there are plenty of other ways).