I have a button that is within an updatepanel control. The button's click event has a function defined for it through JQuery. Once the async postback completes the JQuery event fails to fire when the button is clicked subsequently. What do I need to do to correct this behavior and maintain the JQuery event attachment to the button's click event once it has been refreshed asynchronously?
put your jquery event handler binding inside the following function
function pageLoad(sender,args) {
// binding code here, for example
$('#button').click(function(e) {
// do something when the click event is raised
});
}
pageLoad is executed after every postback, synchronous or asynchronous. pageLoad is a reserved function name in ASP.NET AJAX that is for this purpose. $(document).ready() on the other hand, is executed only once, when the DOM is initially ready/loaded.
See this Overview of ASP.NET AJAX client lifecycle events
Related
i have a textbox on a page, now whenever any age number is entered in that page, that page should be loaded in my datalist, i have created rest of the thing, but i am not getting how to trigger the textbox onkeydown event from asp.net, i know working with that from javascript, but the problem is i have below things done in that function:
it applies the currentpage value to the static variable from textbox
it binds the datalist
it enable disable the next previous buttons accordingly
and i dont think this i can do from javascript, anyone have any resolution, how this could be achieved from server side, onkeydown event
You can capture the keydown event in a javascript function then do a AJAX call to the server. If this does not suit you, then you could try manually do postback in javascript.
So in your textbox:
mytextBox.Attributes.Add("onkeydown", "return doDataListBind()");
Now in the javascript function:
function doDataListBind()
{
__doPostBack("myTextBox"); // etc, etc
// some other code here...
}
More info can be found here:
http://geekswithblogs.net/mnf/archive/2005/11/04/59081.aspx
http://www.asp.net/ajaxlibrary/AjaxControlToolkitSampleSite/
Try looking into or using either:
AJAX Control Toolkit, or
JQuery Autocomplete Plugin
Alternatively you could try to call _postback() function from a client side event/function for your textbox in javascript
I have two radio button on my asp.net page, with AutoPostBack = True
When I click on either of those, they each set a flag SaveData=False
However, when I click on them, the page_load event occurs first, so the page_load event saves the data, then the radiobutton_OnCheckedChanged event is triggered.
How can I trigger the OnCheckedChanged before the page_load event?
You can't.
You need to read up on the page lifecycle.
You can't trigger the OnCheckedChanged before radiobutton_OnCheckedChanged because that's the normal page life cycle.
You can check in Page_Load if Page.IsPostBack is true or not, and then don't save (or save) the data.
Troy - you will have to take care of this on the client side (javascript / jquery).
Your AutoPostBack = True causes the form to do a postback which calls page load.
Its all about how the page lifecycle and server side events work.
You can't the page always needs to load before events can be fired. This has to do with control creation, view state management, control state, etc.
What you want to do in your Page_Load is something like:
if(!this.IsPostBack)
{
// Do the stuff you want on the initial page load
}
Anything that you do not want to happen when the radio buttons are clicked, put it inside the if {} block. IsPostBack indicates that the page is processing a post-back event, which is what happens when you click one of your radio buttons.
You can't change the order/sequence of event handler execution. However you may move the code inside the page_load to another event handler.
There is a drop down list in the jquery ui modal form with id - drpAction.When the selection is changed I need to execute drpAction_SelectedIndexChanged function in the code behind. When I just try to invoke the function like onSelectedImdexChanged="drpAction_SelectedIndexChanged" ,the function is not fired.
How can I solve the problem?
Do you want a full postback, or an AJAX call? For full postback, add AutoPostBack="True" to your DropDownList. For an AJAX call, you should hook a JQuery event handler to the DropDownLists "onchange" event (remember that a DropDownlist is rendered as a SELECT tag)
This is probably a simple question.
I use ASP.NET ajax toolkit and Jquery. I want to call a server-side function/method from Javascript and have it update a control. Can i do this?
Client-side
send_request(foobar,args);
Server-side
private void foorbar(){
Label1.Text = "updated";
}
Do you want it to fire a server-side method and update a server-side control on the page? You can create a ASP.NET UpdatePanel, let's say there is a button1 inside, and from your JQuery code, write this.
function OnClick()
{
__doPostBack(button1.ClientID, "argument")
}
and in your server side code, Page_Load event, you will find the EVENTTARGET and EVENTARGUMENT in the REQUEST variable, which contains the information you just postback, you can then update the control in the UpdatePanel itself as long as the control is within the UpdatePanel, it will be handled properly by ASP.NET AJAX.
More details here
http://www.dotnetspider.com/resources/16920-Post-back-gets-demystified-doPostBack-defined.aspx
Yes that can be done Client Callback
You could take a look at ASP.NET Page Methods.
jQuery.ajax({
url:'url to call', //usually webservices in asp.net
dataType:'json',
type:'POST', //(asp.net werbservices by default accepts POST request only)
success:function(data){
//do some thing with this data, like will dom elements etc
}
});
#smkngspcmn:
I placed everything inside an update panel and did something like $('#Year').change(function() { __doPostBack("submit", ""); }); That does do a full post back without Ajax. What am i doing wrong? Should i place the above script inside the update panel as well?
The first argument to __doPostBack() should be the UniqueID of a server-side control inside the UpdatePanel. For example, you can put a hidden button inside the UpdatePanel:
<asp:Button ID="HiddenButton" runat="server"
style="display:none" OnClick="HiddenButton_Click" />
When the button is rendered on the page, you can take the name attribute of the <input type="submit"> element that represents the submit button and use it for the first argument to _doPostBack(). In this way, whenever your script runs it the UpdatePanel will make an asynchronous postback and the HiddenButton_Click event handler will be fired.
I am using JQuery to toggle the visibility of a in a webforms application. I am using an update panel to suppress the postback when my is clicked. What I would like to do when this is clicked is call the JQuery code that I use to toggle the once the postback has completed. What code(client-side or server-side) do I need to implement? Thanks you.
Edit:
I don't just need to fire the toggle event when the postback has completed, but when server-side code says that the user's input is valid.
you can try this on server side:
if(<input is valid>)
{
ScriptManager.RegisterStartupScript(this.Page,this.Page.GetType(),"Toggle", "your javascript function call", true);
}
this will call your function when the postback completes
Sure:
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
This is a JavaScRipt callback. Just plug you handler in to toggle your code