Hi Lewis,
As for the exception you mentioned, it does be caused by the Event
Validation since you have some javascript generated html field which will
post data to server-side. So far the "EventValidation" can only be
configured at page level. Though it may involve some risk, but it is
necessary if we need to include dynamically generated html fields on page.
Sincerely,
Steven Cheng
Microsoft MSDN Online Support Lead
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--------------------
Quote:
>From: "Lewis Holmes" <enate@nospam.nospam>
>Subject: EnableEventValidation exception when dynamically adding controls
on client with JavaScript
Quote:
>Date: Wed, 30 Apr 2008 13:33:53 +0100
Quote:
>
>Hi
>
>I have the following situation in one of my asp.net pages.
>
>The user can add multiple table rows to a form by selecting a button.
These
Quote:
>rows can contain asp.net controls. When this button is selected, the row
is
Quote:
>added using JavaScript. The script uses cloneNode to clone a hidden
template
Quote:
>row and all of its children and then adds the new row to the table,
updates
Quote:
>all of the child control Ids and sets visibility etc.
>The hidden template row which is cloned to create the new rows is created
in
Quote:
>server-side code and then hidden on the client using javascript so that
the
Quote:
>user never realises it is there.
>
>This is works correctly if I turn EnableEventValidation off on the page,
but
Quote:
>with it on I get the exception "Invalid postback or callback argument."
>
>I understand why this exception occurs (because I am creating new controls
>on the client which are posting values back to the server), however is
there
Quote:
>any way I can stop this exception from happening without turning
>EnableEventValidation off?
>
>I must stress, the controls are being created using JavaScript and so from
>what I understand I cannot register them for event validation server-side
>using something like:
>
>protected override void Render(System.Web.UI.HtmlTextWriter
>writer)
>{
>base.Render(writer);
>
>this.Page.ClientScript.RegisterForEventValidation (control.ID);
>}
>
>If there is no other way to stop this exception from happening, what can I
>do to minimise injection attacks that may occur with
>EnableEventValidation="false"?
>
>Thanks
>
>Lewis
>
>
