ASP.Net UpdatePanel ImageButton causes "this._postbackSettings.async is null or not an object"

Question

I get this error on an update panel within a popupControlExtender which is within a dragPanelExtender.

I see that a lot of other people have this issue and have various fixes none of which have worked for me.

I would love to hear a logical explanation for why this is occurring and a foolproof way to avoid such issues in the future.

I have found that like others maintain this error does not occur when the trigger is a LinkButton rather than an ImageButton, still wondering if anyone has an explanation.

Siderite Zackwehdex · Accepted Answer · 2019-12-15 14:16:53Z

2

I've had the same problem and haven't really found any satisfying solution until I ended up on https://siderite.dev/blog/thispostbacksettingsasync-is-null-or.html which does exactly what I want.

Just to avoid problems with possible dead links in the future here is the code:

var script = @"
if (Sys &&
    Sys.WebForms && Sys.WebForms.PageRequestManager &&
    Sys.WebForms.PageRequestManager.getInstance) 
{
    var prm = Sys.WebForms.PageRequestManager.getInstance();
    if (prm &&
       !prm._postBackSettings)
    {
        prm._postBackSettings = prm._createPostBackSettings(false, null, null);
    }";

ScriptManager.RegisterOnSubmitStatement(
    Page, 
    Page.GetType(), 
    "FixPopupFormSubmit", 
    script);

In case of a submit without the _postBackSettings being set it creates them, causing the null reference exception to disappear as _postBackSettings.async is then available.

Hope this helps,

G.

edited Dec 15, 2019 at 14:16

Siderite Zackwehdex

6,6283 gold badges33 silver badges49 bronze badges

answered Feb 24, 2011 at 13:15

Gorgsenegger

7,9286 gold badges58 silver badges103 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

YonahW Over a year ago

it's been a really long time since I last had to deal with this issue as I don't use Microsoft Ajax anymore, but this looks like a nice clean solution.

Thunder3 · Accepted Answer · 2008-09-12 16:44:49Z

1

My best guess is that the UpdatePanel is not able to write out the custom "async" property to the postback request properly. This is likely due to blocking from one of the controls wrapping it (my gut feeling is that it's the popupControlExtender - it tends to have odd behavior with updatepanels, as it is intended to manage the events inside it for it's show/hide purposes).

I would recommend either removing the updatepanel and rolling your own solution for your specific business need for having it there, or implementing your own popup script (probably slightly easier to write).

Incidentally, for some background, the "this._postbackSettings.async" is your AJAX.NET framework trying to figure out whether this is an async call or not. You might be able to overcome it by setting this programaticly before the postback is sent (catch the postback event and add the field to the postback request if it is not already there).

Just some thoughts...I do not believe there is a "plug and play" answer for this one!

answered Sep 12, 2008 at 16:44

Thunder3

1,1201 gold badge7 silver badges10 bronze badges

1 Comment

YonahW Over a year ago

I ended up using a LinkButton with an Image which I found to be the simplest solution, although what you suggest is probably more reliable in general.

Matthew Timbs · Accepted Answer · 2009-01-02 19:38:48Z

1

Settign "EnablePartialRendering" to false on the ScriptManager control prevents the error, but it is not an optimal solution. Losing the benefit of partial rendering could be a big deal, depending on your application.

Just for the record, I wasn't doing exactly the same as other folks who saw the error. I have a PopupControlExtender, in which is a checkboxlist. I added a "select all" link with a javascript method to programmatically select/deselect all. I'm not using an Imagebutton. I didn't see the error before adding the javascript and now even after removing it the error remains. There has to be another change I'm missing.

I hope this helps someone...

--Matt

answered Jan 2, 2009 at 19:38

Matthew Timbs

4351 gold badge4 silver badges11 bronze badges

Collectives™ on Stack Overflow

ASP.Net UpdatePanel ImageButton causes "this._postbackSettings.async is null or not an object"

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related