AJAX :: UpdatePanel Is Not Working - It Always Postback Instead Of Callback?
Jan 21, 2010
I have updatePanel in my ASP.NET 2.0 (migrated from ASP.NET 1.1) web app. It doesn't work as it always postback instead of callback. I already set<xhtmlConformance mode="Transitional" /> but still not working. Previously, it just working.
I've got a problem that after i refresh an update panel all the HoverMenu's stop displaying, it still calls the WebMethod which returns valid html and the panel is displayed, but it content of the panel isn't displayed on the browser.
I've created a single page to demo this problem:
aspx
[Code]....
vb.net
[Code]....
The demo shows the hovermenu working until you click the update button then it stops showing the content, although it is still calling the WebMethod onhover.
I am using VS2008, .net Framework 3.5 and toolkit 3, 0, 30930, 0
Now i am having two dropdown one is asp dropdownlist and 2ND is MultiSelect-DropDownList-with-CheckBoxes. 2nd dropdown is populating on selected value of first.On page load it works fine. Now, on change of value in dropdown, selected index change 2nd dropdown (MultiSelect-DropDownList-with-CheckBoxes) fills but i see a list box instead of dropdown.
I have a updatepanel which contains of a few dynamically created ImageButtons (the ImageButtons are placed in a panel inside the updatepanel) Since the imagebuttons are children of the updatepanel they automatically triggers a callback to server, fine. But I want the user to be able to cancel the callback after clicking on the imgbutton, preferably through a javascript window.confirm.
I have managed to make it work with a jquery function returning false (i dont know why it works, dont really understand asp.net ajax functionality) but it only works until a callback is done, then I guess I have to rebind the jquery to the controls in the updatepanel or?this turned out to be a jquery question. How do I rebind the recently loaded controls in my updatepanel to my jqyery function? the controls all have the same class and I use that to trigger the jquery function.
i have had this problem before but haven't found a solution yet. The solutions that i have come across are either bad for security or worked on old versions of the .Net framework. I am using VB.net with framework 3.5 and i get the following error when clicking on a button that is a trigger for an updatepanel:
Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
The msg states that you need to use the ClientScriptManager.RegisterForEventValidation but i can't find anywhere which shows a working example of this in VB.net & in .net framework 3.5. Can anyone give me a step by step guide on how to resolve this postback validation error?
Whenever a postback would occur (AJAX'ed by an UpdatePanel) I want to do a callback beforehand and only after the callback has completed (either successfully or not) should the postback occur. How can I do this?
Elaborate explanation: We use ASP.NET AJAX (UpdatePanel 'n stuff) together with DevExpress controls. Among those controls is the ubiquitous GridView. As is typical with ASP.NET gridviews, you can edit rows one-by-one, and to save your changes you have to hit the "update" button at the end of the row. However if you make some changes to the row, then forget to press the "update" button, and hit something else in the page (say the big red SAVE button that causes a postback and saves the whole form to the DB), your changes will be lost. The row will still be in edit mode, but it will have reset to the data it had initially when you started the edit.
Our clients are not happy with this and want the row to be saved automatically if the user forgets to do so himself. Luckily the DevExpress gridview is smart enough to have an "Update()" method which I can call from JavaScript. Unluckily that causes a callback and returns immediately. If I allow the postback to continue as normally, the callback will get aborted. Well, technically it's a race condition I guess, but so far it seems that the postback wins. There are events to which I could attach for success/failure of the callback, but I don't know how to "resume" the postback that started it all. We could turn off callbacks for all the grids, but that would be a performance disaster.
I'm having this wierd issue I hope you could help me with.I have two drop down lists in my page, and an accordion.When a value is chosen for the first DDl it loads specific values from my database into the second ddl.I've put the second one inside an Update panel, and added the first DDL as AsyncTrigger, so whenever someone chooses a value from the first DDL it loads the second one without refreshing the page.After a value has been chosen for the second DDl the accordion should be populated with data.I've ran some tests and noticed that choosing a value from the second DDL won't populate the accordion, so I've added another PostBack trigger to the second DDL- the ddl itself.Sometimes it works fine- I choose a value from ddl2 and the accordion shows fine, but sometimes I get this error message:Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation."Before putting the second ddl inside the update panel everything worked well so I'm a bit baffled here.
But I have another problem, my gridview is inside UpdatePanel and when I click on prev or next button I get exception: "Sys.WebForms.PageRequestManagerServerErrorException: Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation."
Do you know what should I do to make it work?I don't think that I should change enableEventValidation to "false" maybe I should use ClientScriptManager.RegisterForEventValidation? But I don't know how to use it.
i use cascading dropdown lists (in a user registration form) and when the user hits the submit button i get the error: "Invalid postback or callback argument" I've seen on the net that this is a problem dating back many years but still haven't found a solution to this. I've read about changing EnableEventValidation to false, but this poses a security risk.
I have a web user control with one updatepanel (pnlUpdate_2), some controls and one apply button. I display the web user control as a modalpopup in my default page. In my default page i have an updatepanel (pnlUpdate_1) with a gridview and I modify that gridview with the apply button of the web user control. The web user control is for made a custom search of the gridview data. I have a problem with both updatepanels. If I set the updatemode as always in one of them (pnlUpdate_1) and the other as conditional (pnlUpdate_2), the pnlUpdate_1 make a postback in the pnlUpdate_2; I'm not an expert on this but I think that's why the pnlUpdate_2 disappear and reappear after postback of some controls in that updatepanel (not the apply button, it close the modal after postback). I try all the combinations and the problem persists. So I put both updatepanels as conditional and in some way it works; now the problem is that when I click the apply button in pnlUpdate_2 to modify the gridview in pnlUpdate_1 the pnlUpdate_1 not made the postback I get the pnlUpdate_2 postback when I use some control inside the pnlUpdate_1.
How can I postback the pnlUpdate1 from pnlUpdate_2 with the apply button?
I want to load a popup when a user clicks a button. The buttons are images located inside a tabpanel. The first time the page is loaded the helpEvents DOES display the popup and the 'click' popup. Then I navigate to Tabpanel tab2, and the helpTickets button doesnt work (doesnt even display the 'click' popup) Then I navigate back to Tabpanel tpEventDetails, and the helpEvents button doesnt work anymore either(and also doesnt even display the 'click' popup anymore) So I think something gets lost in the updatepanel on callback...but what? and how to fix it?
I have a web page that contains a number of update panels containing collapsed panels, some of which have data loaded on expand.To achieve this I have added a java script function:
function pageLoad() { $find('cpe1').add_expandComplete(postBack1); $find('cpe2').add_expandComplete(postBack2); [code]....
With the PostBack1 - 4 functions clicking hidden buttons that are triggers for the update panels (and inside the panels) that then run the loads. In some of these it binds a grid to an object datasource in others it just fils in some screen elements from a database table.
What I am finding is that the ones which load screen elements work perfectly. The FIRST one of the two grid binding ones also works perfectly, and it doesn't matter which I open first (both up1 and up2 will work if they are first and correctly bind the grid). However if I open either of the grid binding panels then attempt to open any other panel I receive:
"Sys.WebForms.PageRequestManagerServerErrorException: Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation."
However this only occurs if I hit either up1 or up2, I can open and close up3 and up4 as often as I like with no error as long as I do not open up1 or up2.Turning off Page event validation does solve the problem, but I am concerned about page vulnerability.
I have a Cascading drop down list that is working fine to load the correct lists however I would like to have the last one initiate a query and display a datagrid on the same page containing the results of the query. Without Ajax involved this seems rather easy by using autopostback on the drop downs. If I could do it through Ajax that would be great but I can settle with having the page to reload to display the data. Right now I'm not sure how to do either. I enabled autopostback on the last drop down and wrote a method for it but I get an error at runtime saying:
What is the best way to ensure that events are rebound after an UpdatePanel callback?
function pageLoad(sender, args){ //bind events here. } or use the .live(eventType, handler) method to initially bind the events or var prm = Sys.WebForms.PageRequestManager.getInstance(); prm.add_endRequest(function() { //bind events here. });
I wanna assign a JavaScript CallBack function to an UpdatePanel which will be gets called when the UpdatePanel finishes its tasks. After, the UpdatePanel will be sending a string as a result. This JavaScript CallBack function will have to process this resulting string.
I am aware that a FileUpload requires a full page postback. I read the article http://www.4guysfromrolla.com/articles/090209-1.aspx[^]I tried to install a PostBackTrigger programmatically to get a full postback only on the ImageButton1 control. All other postbacks must be partial. (GridView sorting, paging, ...)In code behind I do :
[Code]....
The above code does not seem to install a full postback only for the ImageButton1, so the file upload fails. How can I make this work ?
I have got the following gridview with a UpdatePanel and approve and save button in each row. How do I create a full postback if approve button is click and asyncPostback if save button is click.
I have a webform which has an updatepanel with a combobox, add button, delete button and a table. The functiion of the two buttons is to add or delete table rows. However, the table is getting cleared everytime the combobox item is selected. Is there anotherway of retaining the table contents?The code for the updatepanel is:
I have an Usercontrol which has a update panel that being postback by a timer, and it is nested in a parent page which has its own update panel. Every time that the update panel in UserControl cause a postback to server my main page's scrollbar being reset to top or buttom of the page. I enabled viewstate of parent page but nothing, and when enable parent page's MaintainScrollPOsitionOnPOstback it cause a problem for Usercontrol updatepanel postback !
I'm reading about the UpdatePanel and how it interacts with controls inside & outside of it.
My understanding is that the usual ASP.Net pipeline takes place when posting from within an UpdatePanel-- Page load etc all fire off as normal-- except when the prerendering stage is reached. In that case the ScriptManager does a final check and only renders those controls within the UpdatePanel and skips the rest. That's my understanding at least.
Sounds good, but for argument's sake let's say I have a TextBox located outside an UpdatePanel. If a postback occurs from within that panel, the TextBox's properties can still be set in the page load method, but those changes will not take effect. (normally; it is possible to postback the entire page from an UpdatePanel)
Is that correct? What happens to that TextBox's ViewState in this instance? Is it updated based on what happened to it in the page load method or is that modification tossed out because it wasn't in the UpdatePanel?
I have a simple form containing a gridview that displays some records. Everything works fine but I was hoping to wrap the grid view inside an updatepanle to prevent a full postback (flickering) when paging.
It doesn't seem to matter what I try, paging always causes a full postback which causes the page to flicker. What am I doing wrong?