Drop Down List (in Update Panel) causing FULL PostBack!

Question

I have a problem with my AJAX and ASP.NET 3.5 :( Problem is really weird, as I\'m using the same thing on different page and it works fine in there, but on this specific pag

Answer 1

Setting the AutoPostBack attribute to true should be enough to cause a partial postback but it's not what happens and a full postback is triggered instead as you correctly described.

The following workaround works for me:

1. Drop the AutoPostBack attribute.
2. Trigger the postback using the "onchange" client side event.

This is how the original DropDownList should look like:

<asp:DropDownList ID="ddlNewService_PortTelco" runat="server" Width="250" CssClass="dropdown" OnChange="javascript:WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions(this.name, '', true, '', '', false, true))" OnSelectedIndexChanged="Provision_PortedTelcoChanged"></asp:DropDownList>

For more details regarding the WebForm_PostBackOptions parameters see below:

function WebForm_PostBackOptions(eventTarget, eventArgument, validation, validationGroup, actionUrl, trackFocus, clientSubmit)

http://msdn.microsoft.com/en-us/library/system.web.ui.postbackoptions_members(v=VS.90).aspx

Answer 2

One alternative to fix this issue is:

Declare the library

using AjaxControlToolkit;

Then you can do something on these lines

private void InitControl()
{        
            //FIX - DROP DOWN
            ToolkitScriptManager scrManager = (ToolkitScriptManager)Page.Master.Controls[0].Controls[0].FindControl("manScript");
            scrManager.RegisterAsyncPostBackControl(ddlNewService_PortTelco);
}

Answer 3

Me having the same problem...

CHECK your WEB.CONFIG

<xhtmlConformance mode="Legacy"/>

for this line.. and JUST REMOVE IT!!

Worked for me. Thanks http://andrew-murphy.co.uk/?p=152

Answer 4

i had the same problem... altho it's not showing in the copied code here, check to make sure you don't have any controls with ClientIDMode=Static within the updatepanel .... make them inherit

at least any controls that may trigger a postback

Answer 5

Set AutoID value to ClientIDMode property. It worked for me. I have had different behaviour in different browsers (i.e. Google chrome and Firefox).

Answer 6

I had this problem. My Dropdownlist was inside of an HTML table and I had my Update Panel wrapped around two individual rows. I fixed the problem by wrapping the Update Panel around the entire table rather than just the two rows.