I have an gridview that I am adding onclick events to a checkbox column via:
cb.InputAttributes.Add("onclick", "checkClick()");
everything works fine, but when the user clicks the save button on the form, (which is within the updatepanel), suddenly the onclick event of the checkboxes stops firing!
Is this a problem with the ASP.NET AJAX?
The weird thing is that I am seeing the onclick event on the source, it just doesn't fire.
Help!
The source will show you the state of the document when first received from the server, not the current state of the DOM. What is likely happening is the update panel content is being replaced by new HTML content. The elements to which the original click events were bound are no longer in the dom.
The onclick events will need to re-bound to wire-up to the new elements that have arrived.
Related
I have the following scenario:
UserControlA contains a <asp:Button id="bSomeid" onClick="AddItem" /> with some code to an item to a shopping basket in AddItem.
UserControlB contains some LinkButton's that dynamically add a selection of UserControlA to the page in the OnClick event.
This is all done in an UpdatePanel. It is a little more complicated but I have pruned the information to what I believe is causing the problem, I will add more information if necessary.
The problem I have is that it takes 2 clicks for the AddItem event to trigger after I have added the items to the page after clicking the LinkButton.
I understand why this is happening - it is to late in the page cycle to register events for the next post back in the onclick - but can anyone think of a way around this? Can I force an event to be triggered on the next postback? I have tried to think of a way to run my code in page_load but I requuire access to the sender in the onClick.
Using .NET 4.0.
EDIT
I managed to find a way to get the link button sending the request in the Page_Load (using Request.Form["__EVENTTARGET"];) so I moved my code to the Page_load event. It still requires 2 clicks so I am assuming it isn't something to do with the onClick being registered to late.
Are there any other general things to check that could cause a button to require 2 clicks to post an event properly?
If your suspicion about being late in page life cycle is true then you can try using ScriptManager.RegisterAsyncPostBackControl method to register dynamically added controls in the link button click - considering that your button is within user control, you need to add public method into UserControlA that would actually register the button bSomeid1 and link button click from UserControlB would actually call the A control's method.
EDIT :
Another cause for button click not happening can be that button being dynamic control is not added in the page hierarchy when post-back happens (or it gets added very late in the page life cycle when the post back data is already processed). A really full-proof solution should add dynamic controls back to the page hierarchy in page_load it-self (and strictly maintaining same controls ids within hierarchy). If that's not possible then you can sniff the request (Request.Form) to detect the post-back.
In your case, you should ascertain if the button is indeed causing the post-back on each click. If yes, what is the POST data (Request.Form) for the first request - what is the __EVENTTARGET value on the first click (and post-back)? That should start your trouble-shooting.
On the other hand, a simple work-around could be to use html anchor element (you can still use link button) and have a javascript handler in the click event that would set some hidden variable and then submit the form (you can simulate the click on hidden button to trigger ASP.NET client side submit pipeline) . Now the hidden variable value can be used on the post-back to determine which link button has been clicked.
"Are there any other general things to check that could cause a button to require 2 clicks to post an event properly?"
Does it require two clicks on the control, or does it take accept a single click elsewhere on the screen, and then fire first time with a single click on the control?
I have my own (similar) issue with the Updatepanel where the first (expected) trigger does not fire and it seems that a single click elsewhere, and then the subsequent triggers fires first time (which totals 2 clicks)
[edit] Since you are working on this ATM, it may help me as well. Do you have a textbox with a trigger event on it? I do, and if I leave this blank (so that it does not fire) then there is no need for a second click.
This is what I'm trying to do with AJAX:
[DropDownList]
I have a DropDownList (not inside an UpdatePanel), populated by different Products to "Add" to the database.
[UpdatePanel #1]
Below, I have an Conditional UpdatePanel that listens for "SelectedIndexChanged" on the DropDownList, when that event is triggered it adds TextBoxes to a div "productForm" inside the UpdatePanel. It creates the Form according to the Product to add.
[Button]
Below the UpdatePanel I have a button that "should" submit the form above.
[UpdatePanel #2]
I have an update panel that listens for the event on Button "Click" event. I also have a div in the ContentTemplate that should post out data that was submitted from the "Add Product Form" in the first UpdatePanel.
The thing is, when I submit (and the Controls are still visible in the first UpdatePanel. It can't read the data from the TextBoxes becaus they aren't there. Also, if I try to add all this to the same UpdatePanel, the Controls disappear whenever I click the Submit button.
Any ideas how to make something similar work?
Without the code I can suspect that when you dynamically populate first div on dropdown selected index changed event, since its within update panel, viewstate is never made aware of new controls and on submit can't post them back to server.
I've had some bad experiences with update panel and never use it other than very simple scenarios. Try getting familiar with jQuery ajax. I would do what you want to do using jQuery and web methods.
I have a button on my page and and few textboxes which alters their context on page_load event. when I open the page for the first time it loads random data from a database to textboxes with a function in pageload and also I create those textboxes dynamically. what I want is to make some changes on textboxes texts and click the button than send new context of textboxes to database. But when I click on button, PageLoad event fires again and It regenerates the textboxes and the context of them alter naturally since they are newly created textboxes. I tried to use "if(!Page.isPostBack)" in pageload but then the textboxes and related objects are not being created and they become null.
how can I overcome this problem?
best thing I can think of is to find some way to fire buttons click event without firing PageLoad event, but I dont know how can I do it.
any help would be appreciated;)
From Comments
Can you regenerate the Textbox on each Page load Execution? and data assignment to these Textbox should be under !Page.IsPostback. All you have to do is to keep the IDs of the Textbox in ViewState only first time page load and next regeneration of Textbox will have the previous stored ID and you also have to store the ID corresponding data in ViewState. Makes sense?
I've got an ASP.NET application that I'm accessing through Google Chrome. On a particular page I've got an asp:TextBox with a OnTextChanged event that recalculates a few other fields on the page. I've also got an asp:LinkButton with an OnClick event that saves the changes to the database.
I was facing a problem where the user left the TextBox by clicking on the save button. The button was firing before the TextChanged event so the changes were not being captured in the save. I fixed this by duplicating the TextChanged logic at the beginning of the save method. Did some testing before I committed these changes and everything was working fine.
But now my tester is facing a different problem. When he changes the text field and clicks the save button, the OnTextChanged event is firing to update the other values on the page but the OnClick event for the save button is not firing at all. He has to click the save button a second time to get the OnClick event to fire. I tested the same functionality on my machine and it's still working fine for me. He and I are looking at exactly the same page in the same environment with the same database. I had my tester clear his cache etc. The only difference I can find is that my Chrome version is "14.0.835.202 m" while his is simply "14.0.835.202".
Are there any known issues with Chrome and ASP.NET where event firing can be non-deterministic or something? Anyone have any other idea why this might be happening? Thanks for your time!
I believe this is a known issue.
One option is to disable the button (client-side) when the user is typing in the TextBox, and enable it after the TextChanged event completes.
Another option is to remove AutoPostBack="true" and use AJAX instead.
I had a page with 3 update panels... based on textbox changes in updatepanel1, updates the modes of other panels before they click the submit button.
The problem is I created onblur events for the textboxes...once there is a postback everything works fine. But there is one worst case scenario where the user changes the textbox and uses the mouse scroll bar and clicks the submit button. In this case (as onblur event never occurs) I could not able to update the second and third update panels.
One solution I thought was, onclicking the submit button, I was trying to check the previous mode but this will not be possible for my case because of the design issues
You could always attach a Javascript event to the scrollbar to trigger the update as well.
Pseudocode:
window.onscroll:
if contents of textbox have changed:
do postback
else
do nothing