ASP.NET AJAX Control Toolkit

Re: CascadingDropDown not populating

David Anson — Sat, 23 Dec 2006 00:05:52 GMT

I think you may have luck tweaking this setting: http://ajax.asp.net/docs/mref/P_System_Web_Script_Serialization_JavaScriptSerializer_MaxJsonLength.aspx

Re: CascadingDropDown not populating

michaelpimentel — Wed, 20 Dec 2006 20:26:05 GMT

Hello people,

i have same problem here, but my problem is:

try to load a large amount of items, for example.

In the sample of CDD change the webservice "CarsService" method "GetDropDownContents",
insert this code:

for (int i = 0; i < 870; i++)
{
values.Add(new CascadingDropDownNameValue(string.Format("Name{0}",i), string.Format("Value{0}",i)));
}

and the erro 500 show ... my list are 890 items.....

Please Help....

Re: CascadingDropDown not populating

David Anson — Fri, 01 Sep 2006 20:18:33 GMT

"Sys undefined" suggests that Atlas itself may not be installed/configured correctly on that server.

Re: CascadingDropDown not populating

mmai — Thu, 31 Aug 2006 22:07:56 GMT

Hi,

This is my scenario.

In production server (win2003 with IIS 6.0, asp.net 2.0 and asp.net 1.1 coexist),
My drop downs appear blank if I try to use web services to provide the data.
If I use built in page methods and I got 'sys' is undefined.

In development pc, (XP with IIS 5.1, asp.net 2.0 and asp.net 1.1 coexist),
Both web services and page methods work without any problem.

Web.config in both machine were identical.

Does anyone have any idea why?

Thanks in advance.

Michael

Re: CascadingDropDown not populating

your_kanth — Thu, 17 Aug 2006 18:39:49 GMT

Thanks David. I am able to solve by adding aditional attributes.

I have another prob with in the same page. I added a gridview to that page having Edit & Delete buttons.

When ever my page is postback(by clicking button or by grid events ) , it's refreshing twice. Any Idea?

I am using CollapsiblePanel, CascadingDropDown in that page.

kindly reply me if you come across this probulem.

Regards

Kant.

Re: CascadingDropDown not populating

David Anson — Tue, 15 Aug 2006 19:37:01 GMT

My reply from the private email about this issue:

"The web.config for an Atlas has additional settings that aren't present in a default web.config. It sounds like you need to add one or more of those settings to your site's web.config. You might find the windiff utility helpful in identifying the changes. Hope this helps!"

Re: CascadingDropDown not populating

your_kanth — Tue, 15 Aug 2006 15:36:48 GMT

Hi,

My parent dropdown itself is not population. I added EnableEventValidation="false" in page tag. Still no luck.

If i work in " atlas web project", I am able sccess with cascading dropdown. But if i try to do with existing project, i am not able to. No error but first dropdown itself not populating.

I added in web.config

pages>

controls>

add namespace="Microsoft.Web.UI" assembly="Microsoft.Web.Atlas" tagPrefix="atlas"/>

add namespace="Microsoft.Web.UI.Controls" assembly="Microsoft.Web.Atlas" tagPrefix="atlas"/>

controls>

....

pages>

This is my aspx page code:

@ Page Language="VB" AutoEventWireup="true" CodeFile="Default.aspx.vb" Inherits="_Default" EnableEventValidation="false" %>

@ Register Assembly="AtlasControlToolkit" Namespace="AtlasControlToolkit" TagPrefix="atlasToolkit" %>

<atlas:ScriptManager ID="ScriptManager1" runat="server" />

</asp:DropDownList><asp:DropDownList ID="DropDownList2" runat="server">

</asp:DropDownList></div>

<atlasToolkit:CascadingDropDown ID="CascadingDropDown1" runat="server">

<atlasToolkit:CascadingDropDownProperties TargetControlID="DropDownList1" Category="Make" PromptText="Please select a make" ServiceMethod="GetDropDownContentsPageMethod" />

<atlasToolkit:CascadingDropDownProperties TargetControlID="DropDownList2" Category="Model" PromptText="Please select a model" ServicePath="CarService.asmx" ServiceMethod="GetProductGroups" ParentControlID="DropDownList1" />

</atlasToolkit:CascadingDropDown>

</form>

.Vb File:

<WebMethod()> _

Public Function GetDropDownContentsPageMethod(ByVal knownCategoryValues As String, ByVal category As String) As CascadingDropDownNameValue()

Dim values As List(Of CascadingDropDownNameValue) = New List(Of CascadingDropDownNameValue)

values.Add(

New CascadingDropDownNameValue("A", "1"))

values.Add(

New CascadingDropDownNameValue("B", "2"))

values.Add(

New CascadingDropDownNameValue("C", "3"))

Return values.ToArray

End Function

My WebService (CarService.vb):

<WebMethod()> _

Public Function GetProductGroups(ByVal knownCategoryValues As String, ByVal category As String) As CascadingDropDownNameValue()

Dim kv As StringDictionary = CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues)

Dim values As List(Of CascadingDropDownNameValue) = New List(Of CascadingDropDownNameValue)

Dim ProvinceId As Integer

If (kv.ContainsKey("Make") And Int32.TryParse(kv("Make"), ProvinceId)) Then

If ProvinceId = 1 Then

values.Add(

New CascadingDropDownNameValue("a", "1"))

ElseIf ProvinceId = 2 Then

values.Add(

New CascadingDropDownNameValue("b", "1"))

End If

Return values.ToArray

End Function

Any help is highly Appreciated.

Regards

kant.

Re: CascadingDropDown not populating

doshea — Fri, 19 May 2006 18:26:18 GMT

I've been trying to get this example to work so as I can use similar in my own pet project.

Would anyone be kind enough to tell\show me how to create the "Projects" and "FixFor" objects which are defined in the App_Code folder.

I'm getting errors on this line

For Each myProject As Project In Project.GetData

How do I define Project in the TableAdapter?

Rgds

DOShea

Re: CascadingDropDown not populating

columba — Mon, 15 May 2006 09:10:57 GMT

nice1 David,

that had really thrown me, thought it was a vb.net thing. the debugging experience on this could definitely be improved on but at least it's in the forums.

thanks

Re: CascadingDropDown not populating

lestat — Wed, 10 May 2006 01:51:58 GMT

Fantastic - that did the job!

Thanks
Andrew

Re: CascadingDropDown not populating

David Anson — Wed, 10 May 2006 00:55:44 GMT

To fix this, you need to add EnableEventValidation="false" to your Page directive. This should be a FAQ for CascadingDropDown, but basically ASP.NET tries to make sure that postbacks don't contain stuff they shouldn't based on what it knows about the page it sent down. Well, CDD is all about sending back data that wasn't in the page to begin with, so this feature needs to be disabled for pages that use it.

That's the good news. :) The bad news (or better news depending on how you see it) is that this should have been easier to debug. CDD tries to populate the list with error details when an error occurs (see _onMethodError), but it doesn't because a change some time ago to use name/value pairs for the data type wasn't applied to the error methods. I've logged this for fixing in the next release.

But for now, your issue should be trivially solvable by flipping EnableEventValidation as I note above.

Thanks!

Re: CascadingDropDown not populating

lestat — Tue, 09 May 2006 22:07:58 GMT

I've tried setting all three service methods to call GetProjectList, and still no luck - the function's called once when the page is loaded to populate the first DropDown, and not called for the others.

Thanks,
Andrew

Re: CascadingDropDown not populating

sburke_msft — Tue, 09 May 2006 16:42:46 GMT

Cool!

Re: CascadingDropDown not populating

pratibk — Tue, 09 May 2006 10:40:03 GMT

hey shawn, now i get it..hadnt looked carefully through the tool kit code earlier. It makes sense now and the cascadingdropdown works perfectly :)

Re: CascadingDropDown not populating

sburke_msft — Mon, 08 May 2006 17:46:38 GMT

I don't see anything wrong with your code - what happens if you change all three service method's to call the one that's workng? Does it get called then?

Pratibha - I don't understand your question. ID isn't added by the extender at all - you can put whatever you want into the value field of the CascadingDropDownNameValue.