Dropdownlist Does Not Trigger The SelectedIndexChanged?
Nov 9, 2010
I have a dropdownlist (dr1) that is supposed to trigger the update of dr2 without affecting dr3. The problem is that dr1 triggers the update, but does not go into dr1_SelectedIndexChanged. I know that because the label does not change and that the pause does not happen
There are a couple of things going on in this post:
1. The DropDownList (DDL) reverts back to index = 1 on postback (this has been solved, post #10) 2. Use of General Lists to populate the DropDownList (Post# TBD)
I have a series of DropDownLists (DDLs) one depending on the other for its selection value. The first one specifies the table name. On the SelectedIndexChanged event of the table name DDL the second DDL is populated with a list of field names contained in that table. And the third DDL with unique values contained in the selected field (In case you are wondering I am building a custom query tool).
The problem is that the Field names DDL, after selecting a new field, reverts to the second field listed in the table, something to do with the postback I would presume. The interesting thing is that it does not happen for the Table name DDL, though I am doing something a trifle bit different there.
I'll include the code for the three DDLs and the two SelectedIndexChanged events.
I have a DropDown which is bounded to an ObjectDataSource. On its data bound event, I am adding "--select--" value on the 0 index. I have a LinkButton on the page and on its client click, i am selecting different item on drop down (using JavaScript). Suppose there are 3 items like --select--, option1, option2 and option3 and now on link button's client click i selected option3, now if I select the default value "--select--", it does not fire the SelectedIndexChanged event. If I select any other value then it fires. Why does it not work for the default value?
I have a cascading dropdown list on my page. The first dropdown contains a list of events. The second dropdown contains a list of attendees. When an event is selected, an AJAX call is made to get the list of attendees for that event, and populate the second dropdown.
My problem is that for the attendees dropdown, I want the user to be redirected to a URL on the SelectedIndexChanged event, with the selected value in the query string. But on the SelectedIndexChanged event, all the items in the second dropdown are reset. Here's my code:
I have a radiobutton list that changes the contents of a dropdownlist when the selected radiobuttonlist index is changed using the SelectedIndexChanged event. Both controls are within the same updatepanel and both have autopostback set to true.
For some reason when I change the dropdownlist and cause a postback, the radiobuttonlist change event fires and repopulates the dropdownlist which effectively cancels the selection made in the dropdown.
I know something simple must be causing this behaviour but I cannot think what and my debugging efforts are not shedding any light thus far. I have tried putting a breakpoint on every procedure in my form and the first event that fires is the radiobuttonlist SelectedIndexChanged event so nothing in my server side code seems to be doing this which suggests it is something in the markup but I can't think what.
I have one dropdownlist control which populates values to other controls. Means upon selecting item in dropdownlist, related data is populated in other controls. I have also assigned dropdownlist's autopostback to TRUE. Everything is working good as far as dropdown has more than one item.
Whenever there is only one item, selectedindexchanged event is not fired (obviously.....) and eventually the data is not populated to other controls.
How could I get rid of this scenario? I mean which event should I use to avoid this?
At this time, I have just added the first item as something like "---Select Item---" , so when end-user has to select different item and thus the selecteditemindexchanged is fired. no biggie... but just wondering if proper solution is available....
I have a dropdownlist inside a formview and I'm trying to do something on the selectedindexchanged event. but I'm getting the following error:
It looks like it can't find the dropdownlist because it is inside the formview. How can I find the event?- if there is such a thing.
Server Error in '/WebSite4' Application. Compilation Error Description:
An error occurred during the compilation of a resource required to service this request.
review the following specific error details and modify your source code appropriately. Compiler Error Message: BC30506: Handles clause requires a WithEvents variable defined in the containing type or one of its base types.
Source Error:
[Code]....
Line 13:End If Line 14:End Sub Line 15:Protected Sub ddlDept_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlDept.SelectedIndexChanged Line 16: Dim ComDropDownList As DropDownList = CType(FormView1.FindControl("ddlCommune"), DropDownList) Line 17:
I have an ASP.NET DropDownList with AutoPostBack=true and EnableViewState=false. I have a button on the page that does nothing. If I change the selection in the ddl, it posts back , which is expected. If I click the button, the page posts back and the ddl's SelectedIndexChanged fires. Why does it get fired?
Getting an unexpected event firing dropdownlist's selectedIndex event. When I try to redirect from another page by a linkButton. I just changing dropdownlist selectedIndex.Its okay.But after that When I attempt to redirect to another page,DropDownList's selectedIndex event firing (before linkButton Onclick event).But I am not changing any thing in dropdownlist.Somehow its event firing.
also any page viewstates is default (not off).But loading webcontrols into masterpage Page_Load like this :
[Code]....
if this dropdownlist selectedIndexchanged event firing. Because of I am loading webcontrols each masterpage's PageLoadEvent.
What do you prefer this may the reason of this unexpected event firing ? if so. Do you have a better technic to load controls Just for one time and not each pageLoad.maaybe a caching technic I am missing or shoult I use substution.
I couldnt find the main reason why a dropdownlist selectedIndexchanged event firing without I changed anything on that dropdownlist.
what reasons may cause this problem ? if you say viewstate its turned on defaultly. any other reason you know why ?
Basically I have a dropdownlist (ddlSystem) and an AJAX update panel. Inside the update panel I have an asp:GridView (gvSystemSpecs) and an asp:Image (imgLoad).
For triggers on the update panel I have:
[Code]....
When the user changes ddlSystem it makes a service call to pull back a bunch of data and populate the gridview.
I want to be able to show a loading image (imgLoad) when ddlSystem is changed. Once the function to pull data and populate the gridview is complete I need to hide the loading image.
I think I'll need to use some JavaScript, but what ever I try doesn't work and I don't know if the update panel has anything to do with it...
When I select from the first dropdown I want to populate the second. However, this is not happening. The postback is happening, but the SelectedIndexChanged handler isn't being called (I have a breakpoint which isn't being hit). The user controls are created dynamically and put into a PlaceHolder which itself is within an AJAX Updatepanel, with ChildrenAsTriggers set to true.
I take drop down list control ,from below code i bind data into drop down list from database...
public void load() { try { string sCon = gv.constr; MySqlConnection con = new MySqlConnection(sCon); con.Open(); String s = "Select * from company"; MySqlCommand cmd = new MySqlCommand(s, con);
[Code] ...
I used to done select index change event on drop down list bt it's not working... I want select index value of drop down list item into textbox....wat i do?
protected void drpOrg_SelectedIndexChanged(object sender, EventArgs e){ string sCon = gv.constr; MySqlConnection con = new MySqlConnection(sCon); con.Open(); String s = "Select companyid from companyuser where orgname='"+drpOrg.SelectedValue.ToString()+"'";
I have in my MasterPage a DropDownList that appears in all my Pages. I want it to run a specific code when user select another item in the list, but the event SelectedIndexChanged in the MasterPage doesn't work. How can I do to get this event working?
I've got a UserControl that's used inside of an UpdatePanel. The UserControl is a fairly simple form that appears via a ModalPopupExtender (which is also part of the UserControl). There are four DropDownLists, as well as some other UI elements. Three of the four DropDownLists have AutoPostBack="true", with SelectedIndexChanged events that fire on the server and cause some of the other DropDownLists to rebind. Two of the three DDL's that AutoPostBack are working fine. One of them, which I only just added, is showing some strange behavior. Let's say I bind five Items to it: 1, 2, 3, 4, 5. I set the SelectedIndex to 0, which makes 1 the selected item. If I select 5 and then 1 and keep toggling back and forth, everything works fine. The postback occurs and SelectedIndexChanged fires. Every time. If I ever select 2 or 4, the postback occurs but SelectedIndexChanged does not fire. Every time.
If I ever select 3, something bizarre happens and sometimes the value of the DDL reverts to 1. Even though breakpoints seem to show that it's not rebinding and no unexpected code is running. I know your first instinct will probably be that I'm wrong about the rebinding code not running, but I have literally been staring at the debugger for hours trying to find my mistake. Lots of breakpoints. I don't get it -- this really isn't that complicated. But obviously I am missing something. I've put about four hours into this so far and I think I'm just grinding at this point. I could use another perspective.
HTML (and by the way, DropProtocolCycleID is the problem control): <asp:Panel ID="PanelPopupAssign" runat="server" Style="display:none; cursor: move; width:325px; background-color:Transparent;"> <BlueUI:Panel runat="server" ID="PanelPatientProtocol" Width="500px" HeaderText="Assign Protocol"> <table cellspacing="5"> <tr> <td style="width:150px;"></td> <td style="width:50px;"></td> <td style="width:125px;"></td> </tr> <tr runat="server" id="TableRowCategory"> <td align="right">Category:</td> <td colspan="2"> <asp:DropDownList runat="server" ID="DropProtocolCategories" CausesValidation="false" autopostback="true"/> </td> </tr> <tr> <td align="right">Protocol:</td> <td colspan="2">..............................
I create a dropDownList in code-behind, in selectIndexChange of another dropDownList, and add this new dropDownList to page using a placerHolder, everthing its ok, but new dropdownlist selectIndexChange event dont fire!
on SelectedIndexChanged event handling of DropDownList in ItemTemplate of ListView. I put OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" in mark up, with code behind, but only to get Compiler Error Message: BC30456: 'DropDownList1_SelectedIndexChanged' is not a member of 'ASP.webform1_aspx'. How do I make it a member? When I do not put OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" in mark up, BC30456 does not pop up, but nothing happens when dropdownlist selected item is changed.
I am adjusting my DropDownList on my MASTERPAGE to point to resourcefiles - like this:
<asp:DropDownList runat="server" ID="Language1" AutoPostBack="true" OnSelectedIndexChanged="Language1_SelectedIndexChanged"> <asp:ListItem value="0" Text="<%$ Resources:SiteMapLocalizations, DropDownSelect1%>"></asp:ListItem> <asp:ListItem Value="0" Text="<%$ Resources:SiteMapLocalizations, DropDownSelect2%>"></asp:ListItem> <asp:ListItem Value="0" Text="<%$ Resources:SiteMapLocalizations, DropDownSelect3%>"></asp:ListItem> </asp:DropDownList> Problem now is that my SelectedIndexChanged has broken its funktionality in MasterPage.master.vb: Protected Sub Language1_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs) Dim cookie As New HttpCookie("SelLang") cookie.Value = Language1.SelectedValue Response.SetCookie(cookie) Response.Redirect(Request.UrlReferrer.AbsoluteUri) this is for the redirecting to the referrer page End Sub
The sites I mantain are using way too much ViewState and I'd like to reduce that so the size of the page is reduced. I've done a lot to remedy this but I have an issue relating to DropDown lists that use AutoPostbacks.I have a dropdown list with a lot of list items and a good part of the ViewState usage is to hold the list item data. If I disable ViewState and set the AutoPostBack property to true, the page will post back and in the page load I am trying to repopulate the dropdown list with cached data. However, it seems that the SelectedIndexChanged event doesn't fire when EnableViewState="false".Is it possible to make this work without enabling ViewState for the drodown list?
