dynamic cascaded drop down

Hi..

well in my web page based on a parameter user selects i need to create contents dynamically

for eg if A is passed than page will have only 1 drop down but if B is passed it might have 7 8 drop downs in it..

this is one part of the problem..once i am able to create them i need to address there selection index change even which will call again some fucntion

which will reload all othr drop dwon whch were created dynamically

so its kind of generating cascaded drop down dynamically and the parent control id could be more than one

Can some one help me out

in case any one is here wondering what happened to the problem

the solution is same as

http://forums.asp.net/t/1090354.aspx

DropDownLists in 2 separate updatepanels only work once, then dont.

Hey, i have 2 dropdownlists, both databound to my sql server, the first one simply selects anything from the "catagories" database. Autopostback is enabled. The next one is a select to the subcatagories database, with an inner join to catagories on the catagory_id column..

The idea here was to make an ajax enabled cascading databound dropdownlist, and it DOES work... but only once. i tried making the trigger the indexChanged event of the 1st dropdown list, but i have the same results. If i change catagories more than once, i will not get a subcatagory change..

Any ideas?

So not sure why DropDownList1 is in an UpdatePanel, but DropDownList2 is the issue here eh and is in a panel, and has a dependant control, being the first drop down list.

So the second one, add a Trigger like this;

<asp:AsyncPostbackTriggerControlID="DropDownList1"EventName="SelectedIndexChanged"/>

Is that any help? Post a snippet of your page here.

Cheers,

Steve

You should use the Cascading Dropdown of Ajax Control Toolkit, it is specially developed for this purpose. Checkout the live demo of it:
http://www.asp.net/AJAX/Control-Toolkit/Live/CascadingDropDown/CascadingDropDown.aspx

It says AsyncPostbackTrigger was a unknown element... Here's my code:

Catagory:<BR /><asp:DropDownList id="DropDownList1" runat="server" DataValueField="Catagory_ID" DataTextField="Catagory" DataSourceID="SqlDataSource2" AutoPostBack="True"></asp:DropDownList><asp:UpdatePanel id="UpdatePanel1" runat="server" >
 <contenttemplate>
SubCatagory:<BR /><asp:DropDownList id="ddlSubCat" runat="server" DataValueField="SubCatagory_ID" DataTextField="SubCatagory" DataSourceID="ddlsubCatagory"></asp:DropDownList>

<asp:SqlDataSource id="SqlDataSource2" runat="server" SelectCommand="SELECT [Catagory], [Catagory_ID] FROM [db_Catagories]" ConnectionString="<%$ ConnectionStrings:floofieConnectionString %>"></asp:SqlDataSource><BR /><asp:SqlDataSource id="ddlsubCatagory" runat="server" SelectCommand="SELECT db_SubCatagories.SubCatagory, db_SubCatagories.SubCatagory_ID FROM db_Catagories INNER JOIN db_SubCatagories ON db_Catagories.Catagory_ID = db_SubCatagories.Catagory_ID WHERE (db_Catagories.Catagory_ID = @.catid)" ConnectionString="<%$ ConnectionStrings:floofieConnectionString %>"><SelectParameters>

<asp:ControlParameter PropertyName="SelectedValue" Name="catid" ControlID="DropDownList1"></asp:ControlParameter>
</SelectParameters>
</asp:SqlDataSource>
</contenttemplate>

KaziManzurRashid:

You should use the Cascading Dropdown of Ajax Control Toolkit, it is specially developed for this purpose. Checkout the live demo of it:
http://www.asp.net/AJAX/Control-Toolkit/Live/CascadingDropDown/CascadingDropDown.aspx

That looks really nice, is there any way of getting the web service code for vb.net?

Can you post the complete markup of UpdatePanel. If any of your dropdown is outsite the update panel set its AutoPostback=true and create AsyncPostbackTrigger in Update Panel which points to that dropdownlist.

KaziManzurRashid:

Can you post the complete markup of UpdatePanel. If any of your dropdown is outsite the update panel set its AutoPostback=true and create AsyncPostbackTrigger in Update Panel which points to that dropdownlist.

Sorry bout that, thought i had it all.

Catagory:<BR /><asp:DropDownList id="DropDownList1" runat="server" DataValueField="Catagory_ID" DataTextField="Catagory" DataSourceID="SqlDataSource2" AutoPostBack="True"></asp:DropDownList><asp:UpdatePanel id="UpdatePanel1" runat="server"> <contenttemplate>SubCatagory:<BR /><asp:DropDownList id="ddlSubCat" runat="server" DataValueField="SubCatagory_ID" DataTextField="SubCatagory" DataSourceID="ddlsubCatagory"></asp:DropDownList> <BR /><asp:SqlDataSource id="SqlDataSource2" runat="server" SelectCommand="SELECT [Catagory], [Catagory_ID] FROM [db_Catagories]" ConnectionString="<%$ ConnectionStrings:floofieConnectionString%>"></asp:SqlDataSource><BR /><asp:SqlDataSource id="ddlsubCatagory" runat="server" SelectCommand="SELECT db_SubCatagories.SubCatagory, db_SubCatagories.SubCatagory_ID FROM db_Catagories INNER JOIN db_SubCatagories ON db_Catagories.Catagory_ID = db_SubCatagories.Catagory_ID WHERE (db_Catagories.Catagory_ID = @.catid)" ConnectionString="<%$ ConnectionStrings:floofieConnectionString%>"><SelectParameters><asp:ControlParameter PropertyName="SelectedValue" Name="catid" ControlID="DropDownList1"></asp:ControlParameter></SelectParameters></asp:SqlDataSource></contenttemplate> <triggers><asp:AsyncPostBackTrigger ControlID="DropDownList1" EventName="SelectedIndexChanged"></asp:AsyncPostBackTrigger></triggers> </asp:UpdatePanel>

I acctually fixed it... the problem was, there was 3 other updatepanels, and they all need to be set to conditional.

I cant beleive i didnt see that in the first place.