I have a problem with a user control that I use to display images and documents.

Warning: Page has Expired

The page you requested was created using information you submitted in a form. This page is no longer available. As a security precaution, Internet Explorer does not automatically resubmit your information for you.

To resubmit your information and view this Web page, click the Refresh button.  

Any suggestions on how to get around this?

Thanks,

G. M.

This is a standard browser message that comes up if you are trying to return to a page that was generated using an HTTP POST versus an HTTP GET. An HTTP POST request is one in which the user submits a form back to the server. This is typical for most pages where you click on a button to submit information. An HTTP GET request is one in which a page is requested from a server using only the URL. The behavior you are seeing is not DotNetNuke specific -- it is a safety measure to ensure that the user does not re-submit a form unintentionally to the server.

When using Response.Redirect, if you don't include the second parameter set to true, the page processing continues even after the Response.Redirect call is encountered. This might be causing problems with the page output. Try using Response.Redirect(DocViewUrl, True).

In general, since DotNetNuke is an extensible environment, you have to be aware that your code does not "own" the page as it would when used in a standalone aspx page. Therefore, you have to write code that takes this into account as it could affect or be affected by other code on the page.

Nik

In Default.aspx DotNetNuke set the Authenticated Cacheability for authenticated user, the default is ServerAndNoCache. For unauthenticated user the ASP.Net default is Privat. So if you login, there is a difference.

The NoCache in HttpCacheability.ServerAndNoCache and HttpCacheability.NoCache disables caching to force the browser to requery the server for the most up to date data or to prevent posting data twice. The back button or history.back() pulls a page from the browser cache, if the page is expired you get the warning.

The behaviour of your Site also depends from the Browser you are using, because they work differently.

Example:

You have a DotNetNuke module with a Gridview and paging enabled.Go to page 1,2,..,n

a) You are not logged in, the HttpCacheability is Privat (ASP.Net default)
 
   click the browser back button and everything works OK (IE7 and Firefox)

b) you are logged in, HttpCacheability is ServerAndNoCache (DotNetNuke default)

   IE7: click the browser back button and you get an expired message.
   FireFox 2.0.0.3: click the browser back button and you don't get an expired message, it works OK

try to set Response.Cache.SetCacheability(HttpCacheability.Privat) on Load of your Control but this can affect other modules on your page.

For your PDF problem try to use a IFrame.

M.H.