ICallBackEventHandler

[Ben Schumacher]

I have a page that implements ICallbackEventHandler. I'm trying to
accomplish auto saving a page everytime the user navigates away from the
page. To initialize the callback, I fire the onunload event on the window
as can be seen below.

<script type="text/javascript">

window.onunload = Save;

function Save()
{
CallServer()
}

</script>

This works great as I can see in my Page_Load event that the Page.IsCallBack
property becomes true. Now here is where I am stuck. My RaiseCallBack
event fires just as it should, but when i try to read the ".text" values of
all my textbox controls on the form I get whatever was in the previous
viewstate. Not what i typed/changed the textbox to just before the
callback. Whats even more weird is that when the page comes back to the
client after re-rendering it self i can see my changed text box value. So i
fire the callback again, and still i can't read the current value out of the
textbox control. It's like the ICallBackEventHandler interface doesn't keep
track of the changes on the form. It just gives me whatever that last
viewstate values that were generated from a full page POSTBACK not CALLBACK.

Any suggestions?

Thanks,

Ben

[Steve C. Orr [MVP, MCSD]]

New values that the user enters into textboxes are not automatically posted
back via your callback.
Instead you have to explicity grab the values using JavaScript and pass them
back as parameters through your callback.

Here's an example:
http://SteveOrr.net/articles/WebChat.aspx

--
I hope this helps,
Steve C. Orr, MCSD, MVP
http://SteveOrr.net
"Ben Schumacher" <bs*********@navegate.comwrote in message
news:eO**************@TK2MSFTNGP04.phx.gbl...

>I have a page that implements ICallbackEventHandler. I'm trying to
accomplish auto saving a page everytime the user navigates away from the
page. To initialize the callback, I fire the onunload event on the window
as can be seen below.

<script type="text/javascript">

window.onunload = Save;

function Save()
{
CallServer()
}

</script>

This works great as I can see in my Page_Load event that the
Page.IsCallBack
property becomes true. Now here is where I am stuck. My RaiseCallBack
event fires just as it should, but when i try to read the ".text" values
of
all my textbox controls on the form I get whatever was in the previous
viewstate. Not what i typed/changed the textbox to just before the
callback. Whats even more weird is that when the page comes back to the
client after re-rendering it self i can see my changed text box value. So
i
fire the callback again, and still i can't read the current value out of
the
textbox control. It's like the ICallBackEventHandler interface doesn't
keep
track of the changes on the form. It just gives me whatever that last
viewstate values that were generated from a full page POSTBACK not
CALLBACK.

Any suggestions?

Thanks,

Ben