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Cascading Dropdown Web Method Issue

Posted By:      Posted Date: September 20, 2010    Points: 0   Category :ASP.Net


I am having an intersting issue to which I have found no solution, obviously. I am using a web service to populate a couple cascading drop downs. Evereything looks correct to me but I am getting a [Method Error 500] when I run it all. I have the <System.Web.Script.Services.ScriptService()> added to the web service so that's not the problem. What I have found while playing with it is that if I remove the arguments from the web method (ByVal knownCategoryValues As String, ByVal category As String) then it works. This of course is not helpful as I am trying to populate multiple drop downs. I can find nothing on anyone else having this issue.

I am using .NET 3.5 and Ajax DLL version 3.02... 

Also of note is that I have another website, using the same .NET and Ajax versions and this code is working fine.

I have tried everything I can think of, including my last resort tactic of smashing my face on my keyboard, and nothing is working. I am at a loss. Any help would be appriciated. Thanks.

Drop Downs:

<asp:DropDownList runat="server" ID="ddlPlateType" Width="250px" />

<ajax:CascadingDropDown runat="server" ID="cddPlateType" TargetControlID="ddlPlateType"

View Complete Post

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EXPERT: Method error 500 in dropdown (solution is NOT adding System.Web.Script.Services.ScriptServic


Please only answer if you have read the full question!!

Ok...this thing is driving me crazy!!!!

I keep getting a method error 500 in my dropdown box.

All the posts on the web come with the same solution, but it doesnt work for me!
The code seems SO simple and consists of so few lines....but it just doesnt work!



<asp:DropDownList ID="ddlCountries" runat="server">

<cc1:cascadingdropdown ID="cddCountries" runat="server" Category="Country" Enabled="True" LoadingText="Loading...please wait." PromptText="Choose a country" ServiceMethod="GetCountries" ServicePath="geolocation.asmx"     TargetControlID="ddlCountries"></cc1:cascadingdropdown>

<%@ WebService Language="VB" CodeBehind="~/App_Code/geolocation.vb" %>

<System.Web.Script.Services.ScriptService()> _
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 Public Class geoloc

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