ASP.NET Postback Refresh Problem

[Munsifali Rashid]

If you want to stop this happening, what you could do is a response.redirect
back to the same page, after your server side event has finished running.
This would reload the page afresh, and when the user hits refresh, it
wouldn't prompt them to re-post the form data.

E.g.

Protected Sub Button1_Click Handles Button1.Click

'Your custom code here
Dim foo As String = "foo"

'Redirect back to this page when done
Response.Redirect(Request.Path)

End Sub

Although it would solve the problem, it would be an additional server round
trip, though I'm not sure it can be avoided...

You could try using Server.Transfer(Request.Path, False), but I don't think
this would work as the page redirect would happen in the background, and
when the user refreshes, it would still prompt them to re-post the form
data.

Hope this helps,

Mun




"ChiCKeN DaViS" <ChickenD@nbnet.nb.ca> wrote in message
news:0b7201c352aa$2c300b90$a101280a@phx.gbl...

> Hello there,
>
> I have a rather tough question to answer related to page
> refresh. When visiting a webform for the first time a
> given user can refresh the page as much as he/she likes
> and all is well. When a postback occurs (ie. button
> click, select in datagrid, etc...), the browser will post
> back to the server and the associated server-side event
> for that webcontrol will run. Now the postback has
> happened and whatever server side processing has been
> done... at this point ...if the user trys to refresh
> they will see the dialog that says ...
>
> "The page cannot refresh without resending the
> information. Click retry to send the information again,
> or click cancel to return to the page that you were
> trying to view"
>
> If they click retry ...then the server will re-post the
> webform back to the server and cause that previous server-
> side processing to happen again (ie. run page_load again
> and run a button_onClick again, etc..). I have seen very
> few people mention this problem... This surprises me
> because it is a really big problem. There has to be some
> way around it, otherwise.. what good is ASP.NET? :( Of
> the solutions I have seen ...none of them make any
> sense. Seems only people who dont know what they're
> talking about try to provide a solution to this problem.
>
> It doesn't matter if you provide a server side solution
> or client side. I just need some sort of solution to
> prevent the same events running multiple times as a
> result of refresh. If there is a way of detecting a
> refresh, thats fine too cuz i can suppress the server-
> side processing from happening again if i know its a
> refresh.
> I just can't think of or find any way to detect this.
>
> If there is no way to prevent this .. then every other
> asp.net web application ever built will have this problem
> too.. which is just ridiculous!
>
> Any help is greatly appreciated. :)
> but im not confident that i will get a solution...
> considering no one else has...
>
> -ChiCKeN DaViS
>

[Unregistered]

Hi,

You can keep a session variable and set the value to true at page load event for the first time ie inside "!IsPostBack" condition. then next time onwards you can prevent the execution of set of events first by checking the value of variable stored in the session.