How do I force a full postback from codebehind? - asp.net

I'd like to programmatically force a full page postback to occur after an event is fired by one of the child controls. I can't add any triggers to make this work so it will have to be done via code. Thanks.

Sorry, don't understand. By the time an event in codebehind is running, a postback has already happened.

If you mean a client side event then setup OnClientClick to call what is returned by the following after your other client side functionality:
Page.ClientScript.GetPostBackEventReference(control, "")
(It will be something like __dopostback)

Related

OnClick Event Cancelled but PostBack Still Occurs in IE9 for Submit Behavior

There is an OnClick event attached to a submit button on a webform. The button works in all browsers outside of IE9 correctly. The buttons validation is done by parsleyjs, which is where I would assume the problem is coming from; in that the OnClick event gets cancelled by the validation. However, the postback event still occurs. Even though the postback occurs, it does not fire the OnClick event.
A possible solution is switching to UseSubmitBehavior="true" which does work; however, I would rather figure out what is causing the postback to occur but not fire the event.
Instead of a div you could have an asp:Panel (which renders as a div); and change its Visible property at server side so this way you render it (or not) to the client.
Another option is to use asp:Literal which does not render a div and won't be sent back to the server in its ViewState.
The problem was in the end, that parsley.remote.js an extension of parsley.js was somehow modifying the postback request, so that the EVENTARGUMENT was not supplied. Digging deeper into parsley.remote.js should give way to what is happening.
Removing the library (for me it was unused) corrected it.

ASP.NET control event handler not firing on postback?

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...
Edit: Some clarification... we are dynamically loading the parent control of the ImageButton in the OnLoad event of the page... if that makes sense.
AutoEventWireup is irrelevant. Is your ImageButton loaded dynamically, i.e. not written out in mark up? If it is loaded onto the page late in the Page lifecycle e.g. in PreRender then the event will not fire.
If there is a JavaScript issue your page will not even PostBack. Is that happening?
Did you give the ImageButton an ID?
I def agree with what BritishDeveloper said. I had a similar problem where I was dynamically loading controls, but I couldn't get a reference to the control using Page.FindControl("controlName") Someone pointed out that I needed to keep the page lifecycle in mind. I found out I needed to make sure to load the control in the PageInit because after doing an async postback the control was still there, but not loaded in the postback so there was no way to find it. This was all in csharp codebehind and ajax though, but I'm guessing the control isn't getting reloaded.
So, as it turns out we set the PostbackUrl property on one of our buttons in control A... this caused the event handlers for control B not to fire when a button in control B was pressed.
If you create a control dynamically. Any time you fire a postback using the new created control, you need to recreated it. Just think that your application are running at a server. How can the server hold information on controls created dynamically? Don't use Page.IsPostBack to create postback. PostbackUrl is bad solution. Workarround will be need.
I can go into a little more detail ... I just lost several hours fixing my own issue similar to the issue described here. In the course of creating some search controls, I added a pair of ImageButtons and set the PostbackUrl properties on them. A few days later while testing new code, I noticed that none of my other buttons on the webform were posting back properly. They would fire a postback, but the code-behind was behaving as if every postback was an initial page request and none of the event handlers were firing.
After several hours of troubleshooting, I came across this post. When I went back and removed the PostbackUrl from those two ImageButtons, everything went back to normal. I don't know why it was causing this issue, but the fix mentioned here worked for me. I want to add that my ImageButtons were not dynamically added ... they were in the markup and this issue still cropped up. Search your markup for any controls with PostbackUrl set ... remove that (program around it if needed) ... see if your event handlers will fire properly.

How can I trigger a server-side event from a client-side event?

Short version
All I need is that, in a ModalPopUp, when the DoubleClick event of a ListItem fires, the click event of my OK button should be executed.
Detail
I have a ModalPopUpExtender, which hosts a user control. The user control has an OK and a Cancel button. Along with that, it has a dynamic ListBox added to it. So far, I've considered the following possible solutions:
Use Ajax.Net. But, I cannot afford to have a WebMethod.
Use a ClientScriptCallBack. This will need a lot of JavaScript, since I have made almost every control dynamic.
Is there any other way apart from using an UpdatePanel?
Have a look at this way using __doPostback
calling a VB.net function from javascript

asp.net crosspage postback on click doesn't run

I am trying to get a crosspage postback to work in asp.net 2.0 the issue I seem to be having is the button that I press is meant to use it's on click event to store some session variables based on the values of other controls. This button has crosspage postback property to the relevant page.
The on click event seems to not run at all, it just seems to perform the postback to the other page straight away.
Is this standard behavior? Any work around?
I think I have found my answer
http://community.sgdotnet.org/blogs/chuawenching/archive/2007/03/08/ASP.NET-2.0-DataGrid_2F00_GridView-CrossPage-PostBack-.aspx
Seems like the transfer will be instant, no onClick event will run. The alternative is to use Server.Transfer in the onClick event.
Any other comments appreciated.

Can someone help me with an AJAX race condition that leaves buttons disabled?

I have an AJAX problem. There are some button on the ASP.NET page that I think gets disabled and re-enabled on a postback, which needs to be done for other reasons. There are 2 dropdown menus inside an updatepanel that will use the AJAX. The first dropdown menu updates the second one. There is a client side onblur on the first dropdown that calls the __doPostBack and the server call to the onselectedindexchanged event handler is called if something changed in the dropdown list. The problem is if the client onblur event happens too quickly it seems like the postback happens too fast and the buttons stay disabled.
For example, this happens if the user tabs through the dropdown list quickly. I've read that this is an AJAX issue if the server response is a little slow and the partial rendering messes things up.
Does anyone have a solution for this?
A generic solution can be to use a counter with the control; decrement and disable only if <= 0, increment and enable if > 0. :) The ++/-- operators may not be guaranteed atomic, but they are "good enough".
Hard to say without some code to look at, but... Remember what the first letter of AJAX stands for: Asynchronous. You can't gaurantee when your callback method is actually going to execute. Or, if you make two calls (A then B), you might be getting back a response A then B... but next time it's B then A.
Maybe you could use a boolean variable which you flag while your waiting for the AJAX method to complete and check before you run the code in the onselectedindexchanged event method. That way the onselectedindexchanged event method won't do anything if the AJAX method hasn't finished.

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