How To Prevent PostBack Event Handler From Firing
May 3, 2010
I have a custom class (ServerSideValidator.vb) that validates user input on server side (it doesn't use any of the .NET built in validators, therefore Page.Validate() is not an option for me). I am calling the Validate() method on page.IsPostback event and the class performs without any problem
My issue is, when validation fails (returns false), I want to stop the postback event handler from firing, but load the page along with all the controls and user-input values in them. If I do, Response.End(), the page comes up blank. I can programmatically instruct the page to go to the previous page (original form before postback), but it loses all user-inputs.
I thought of creating a global boolean variable in the page code behind file and check the value before performing any postback method, but this approach takes away from my plan to provide all functionalities inside the class itself. The page object is being referenced to ServerSideValidator.
Seems like all the postback related properties/variables I come across inside Page class are 'Readonly' and I can't assign value(s) to control/prevent postback event from firing.
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Apr 12, 2010
I have a control which has an ImageButton which is tied to an OnClick event... Upon clicking this control, a postback is performed and the event handler is not called. AutoEventWireup is set to true, and I've double checked spelling etc.... We haven't touched this control in over a year and it has been working fine until a couple of weeks ago.
We have made changes to controls which load this control... so I'm wondering, what kind of changes could we have made to stop this event handler from being called? There is quite a bit of Javascript going on, so this could be the culprit too...
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Jul 30, 2010
I have the following Master Page
[Code]....
Which is used in the following Page
[Code]....
With the following code behind
[Code]....
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Oct 9, 2010
Every time I refresh the browser, my button's event handler fires again. How do you prevent this?
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May 10, 2010
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Mar 20, 2011
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Dec 22, 2010
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Feb 11, 2011
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Feb 11, 2011
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Mar 7, 2011
i have a dropdownlist whose autopostback = true , but for some selected text i do want tht the autopostback really shouldnt fire .. using jquery...
however i hav really tried out using removeAttr() to remove attribute and then evt.preventDefault() which ofcourse should prevent the postback...
also tried to set the evt.returnValue = false so that the value returned by the dropdownlist change event is false ...
d code snippet i tried out is like :
[Code]....
none of the above resulted in stopping the postback..
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Feb 8, 2010
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You can see an example of such a page here: [URL]
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[Code]....
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Sep 13, 2010
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Feb 8, 2012
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Tried it in the init, tried adding the control to a placeholder, tried a lot of various things but nothing seems to work.
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Apr 6, 2010
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Dec 8, 2010
In Page_Load, Request["__EVENTTARGET"] is an empty string.
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in regards to validation i have disabled ALL POSSIBLE validation in order to try and eliminate it as a culprit, so i dont understand how validation can be affecting the usercontrol.
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Oct 3, 2010
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[Code]....
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Oct 15, 2010
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Oct 15, 2010
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[Code]....
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[Code]....
if (ds.Tables[0].Rows.Count == 0)
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