ListSearch doesnt work with Dropdownlist AutoPostBack

ListSearch works fine finding a specific item on a dropdownlist, but doesn't fire an AutoPostBack event when I tab over (or tab out).

I found this 3rd party add-on control that does exactly what I'm looking for, but was wondering if there's a similar dropdownlist available from Microsoft.

Check out the "Contact Information" section.

http://samples.asplib.net/AspLibSamples/ComboBox.aspx

Also, any easy way to display the prompt text "left" of the dropdownlist. Apparently, there are only two options: top or bottom.

Thanks.

Hi,

You can use the following code to force a postback when the dropdownlist losts focus.

string script = ClientScript.GetPostBackEventReference(DropDownList1, "");
DropDownList1.Attributes.Add("onblur", script);

Hope this helps.

That did the trick! Thanks!!

ListsearchExtender AutoPostback not firing

I have a Dropdown list control with autopostback = true. I am extending the control with the ListsearchExtender control. When I search the list and hit tab or enter the autopostback works as expected. But if I search the list and then click on the desired list item with the mouse it does not autopostback. I am using version 10920 of the toolkit.

Thanks.

Hi Jdclark,

We noticed that you had postanother thread before. If you have further questions, please feel free to discuss us in theorignal thread.

Best regards,

Jonathan

ListSearchExtender AutoPostback not firing

We have a few list boxes that do an auto post back. When I extend the controls with the ListSearchExtender, the search works, but i can only get the autopostback to fire if I scroll down and click what I want. If i type what i want till it is selected and then tab away, hit enter, or click that item, the autopoastback does not work.

The dropdowns are in a wizard control and the wizard is in an update panel if that makes a difference.

Is this expected behaviour or am I missing something?

Other than that this is a really good new tool in the toolkit.

Hi, I am having the same problem. Here is an example of my controls. The autopostback is not firing. Any help would be appreciated:

<asp:TableCell>
<asp:DropDownListID="ddlConsumer"AutoPostBack="True"CssClass="DropDownLists"runat="server" />
<asp:RequiredFieldValidatorID="valConsumer"ControlToValidate="ddlConsumer"ValidationGroup="Header"Text="*"runat="server"ErrorMessage="Consumer required"CssClass="ErrorMessages" />
<ajaxToolkit:ListSearchExtenderID="lseConsumer"TargetControlID="ddlConsumer"PromptPosition="Top"PromptCssClass="ListSearchExtenderPrompt"runat="server"/>
</asp:TableCell>

There is a workitem related to this issue -- please vote if you are affected by it:

http://www.codeplex.com/AtlasControlToolkit/WorkItem/View.aspx?WorkItemId=8744

I'm guessing you wouldn't want/expect the auto-postback to fire every time an item is selected as you do an incremental search ... I presume you'd want it to fire just when you tabbed away from the ListBox -- or perhaps when you hit enter?

Thanks,

Damian

Yes onBlur or when enter button is pressed.

Thanks, will vote.

I was affected by this as well, but I implemented the following workaround. I hope that this works for you guys:

Basically, I created a client side js method called RaisePostBack that asks for a control reference.
<script type="text/javascript">
<!--
// This function is called by the AJAX List Extender control. It's just an easy way to raise a post
// back event from the client-side. This is only needed because there are child controls that are
// dependent on the requester's selected data in order to retrieve the correct data
function RaisePostBack(Control)
{
// First we need to make sure that the postback event doesn't fire when the value is blank
if(Control.value != "")
{
// Call the postback event
__doPostBack("", "");
}
}
//--></script>

As you can see there is a method being called __doPostBack("", "") which does the magic needed to emulate AutoPostBack="True" on the control itself. I also added the initial check for the value because I'm calling this method onBlur of the control and do not want to have it executed if the user is just tabbing thru the controls. I would also recommend adding an isDirty method possibly.

Here is what I added to my dropdownlist controls:
<asp:DropDownList ID="FacilityDropDownList" runat="server" AutoPostBack="True"onBlur="RaisePostBack(this)" onChange="RaisePostBack(this)">
</asp:DropDownList>
<AjaxToolkit:ListSearchExtender ID="FacilityListSearchExtender" runat="server" TargetControlID="FacilityDropDownList" PromptText=" ">
</AjaxToolkit:ListSearchExtender>

Good luck and happy coding.

This link indicates the fix has been released with version10606 of the Ajax Control Toolkit. I downloaded and installed this, as well as version 10618, but the postback by the DropDownList is still not getting fired.

Am I missing something, is there still a problem, or what? Should I try one of the work-arounds posting in this thread?

Thanks so much for any assistance.

Dan

Hi Dan,

It fires when you leave the ListBox or hit Enter -- there is a method you can call to have it fire the OnChange as soon as a change is made.

Can you let me know if this is the behavior you are seeing?

Thanks,

Damian

I tried hitting enter and also leaving the field with the tab key. moving focus to another textbox on the page. The SelectedIndexChanged did not fire in either case.

Thanks.

Dan

Is it possible that the previous installation of the Ajax Control Toolkit is in play even though I installed the later version? Is there anything in the GAC, for example, that might be messing things up? Is it possible to uninstall before installing the later version?

Thanks.

Dan

An old version of the toolkit is the most likely explanation, however the toolkit isn't loaded into the GAC (the ASP.NET AJAX assemblies are though). Could you double-check the toolkit assembly reference in your solution to ensure that it is pointing to the new toolkit?

Thanks,

Damian

Thank you for the post. This code does work. However, when I implemented it on my page, the postback now makes the entire page refresh, overriding the updatepanel control, which is the original reason I started using Ajax in the first place, to make a client style web application.

Please don't take this as a criticism. I just wanted to post the results I had using this solution, possibly saving someone else a few minutes if they don't want this behavior.

That was the problem. My project was still using an older AjaxControlToolkit.dll. I replaced it w/ the version from 10618 and now it works fine.

Thanks for all your help.

Dan

This was my problem as well. I just downloaded Ajax from the asp.net website. The default download link points you to version 1.0.10301.0. Maybe I'm blind or dense, but I did not see any options for a newer version until I found the previous post. Perhaps if someone from asp.net is monitoring this forum, they could get that link updated to point to the most recent version. Just a thought.

ListsearchExtender AutoPostback not firing

I have a Dropdown list control with autopostback = true. I am extending the control with the ListsearchExtender control. When I search the list and hit tab or enter the autopostback works as expected. But if I search the list and then click on the desired list item with the mouse it does not autopostback. I am using version 10920 of the toolkit.

Thanks.

Hi Jdclark,

I have wrote a sample and it works on my machine. My version is V11119 which is the latest. But as far as I know, there is no such issue reported on Codeplex. So I suggest that you should remove all the unnecessary parts and have a test.

<asp:DropDownList ID="DropDownList1" runat="server" Width="100px" AutoPostBack="true" />
<ajaxToolkit:ListSearchExtender ID="ListSearchExtender2" runat="server"
TargetControlID="DropDownList1" PromptCssClass="ListSearchExtenderPrompt">
</ajaxToolkit:ListSearchExtender>

C#:

protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
ListBox1.DataSource = GetWordListText();
ListBox1.DataBind();
DropDownList1.DataSource = GetWordListText();
DropDownList1.DataBind();
}

If it doesn't work, please feel free to let me know with asimple repro.

Best regards,

Jonathan

Hi Jonathan,

Thanks for the response. I downloadded V1119 and created a simple page. But I still have the same problem.

If I type to search and hit enter it works.
If I change focus it works.
If I dont type to search and just use the mouse to select it works.
If I type to search and use the mouse to click on any item other than the one highlighted by the search it works.

But If I type to search and click on the one highlighted by the search it does not fire the postback until loosing focus.

I know the easiest thing to do is type and hit enter, but I know if I use this feature in my application, inevitably someone will try to click and then complain it doesn't work.

Here is my page code:

<body>
<form id="form1" runat="server">
<div>
<ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
</ajaxToolkit:ToolkitScriptManager>
<asp:DropDownList ID="DropDownList1" runat="server" Width="100px" AutoPostBack="true">
</asp:DropDownList>
<ajaxToolkit:ListSearchExtender ID="ListSearchExtender1" TargetControlID="DropDownList1" runat="server">
</ajaxToolkit:ListSearchExtender>
</div>
</form>
</body>

Here is my code behind code:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
DropDownList1.Items.Add(New ListItem("Apple", "Apple"))
DropDownList1.Items.Add(New ListItem("Orange", "Orange"))
DropDownList1.Items.Add(New ListItem("Banana", "Banana"))
DropDownList1.Items.Add(New ListItem("Pear", "Pear"))
DropDownList1.Items.Add(New ListItem("Pinapple", "Pinapple"))
DropDownList1.Items.Add(New ListItem("Grapes", "Grapes"))
End If
End Sub

Thanks for your help.

Hi JdClark,

Yes, I have reproduced your issue on my machine now. However, I think it is a design pattern rather than an issue.When we type the search text , the DropDownExtender will change its selectedIndex. DropDownExtender won't postback when it select the orignal item. So that's why the page don't postback in your situation. To fix this, ListSearchExtender attach onblur event to the DropDownExtender and it will force the page postback. Here is the code snippet.

 _onBlur : function() { /// <summary> /// Handle the Select's blur event /// </summary> this._disposePopupBehavior(); // Remove the DIV showing the text typed so far var promptDiv = this._promptDiv; var element = this.get_element(); if(promptDiv) { this._promptDiv = null; element.parentNode.removeChild(promptDiv); } if(!this._raiseImmediateOnChange && this._focusIndex != element.selectedIndex) { this._raiseOnChange(element); } }

We cannot find a better way for your situation, so I suggest that you should post your issue as a suggestion toCodePlex so that our developers will evaluate

it seriously and take it into consideration when designing the future release of product.Thanks

Best regards,

Jonathan

Hi Jonathan,

Thank you very much for your answer. Pardon my ignorance, but how do I attach the above code to the onblur event of the Dropdown control?

Thank you.

Hi Jdclark,

It is already contained in the AJAX Control Toolkit's source code. Also the onblur event has been attached to the Extender yet.Based on my research , I was failed to find out a better acceptable formula unless we modify its source code.

Best regards,

Jonathan