Cascading combo-box not functioning properly

2 posts, 0 answers
  1. Xorv
    Xorv avatar
    19 posts
    Member since:
    Jan 2012

    Posted 08 May 2012 Link to this post

    I've two combo-box(Countries and States). Combo-box 2 (States) should load associated States with the value selected in the Combo-box 1(Countries).

    Problem:- first time selection of a Countries combo-box item, loads the correct associated States in the 2nd combo-box. But when an another value is selected in combo-box 1. The Values inside combo-box still displays old values.

    NOTE:- On 2nd time NewValues are loaded properly in combo-box 2. But those are not displayed when the the combo-box arrow is click (Only old values are visible). But if we type anything in that 2nd combo-box, New values are displayed.

    QUESTION:- I want evertime the new values are loaded up in 2nd combo-box, it should be displayed on the click of combo-box arrow. Not just after typing something.


    protected void Countries_SelectedIndexChanged(Object sender, Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs e)
        int countryIDselected = Convert.ToInt32(Countries.SelectedValue);
        bool AdvanceSearchFlag = true;
        Session["AdvanceSearchFlag"] = AdvanceSearchFlag;
        Session["countryIDselected"] = countryIDselected.ToString();
        int totalStates = States.Items.Count;
        int xyz = totalStates - 1;        if (totalStates != 0)
            while (totalStates > 0)
                States.Items.Remove(totalStates - 1);
                totalStates --;
    protected void States_ItemsRequested(object sender, Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs e)
        foreach (StateyLookupInfo state in StateLookupList.GetList(false))
            RadComboBoxItem item = new RadComboBoxItem(State.StateName, State.StateID.ToString());

    <telerik:RadComboBox ID="Countries" runat="server" AutoPostBack="True" OnSelectedIndexChanged="Countries_SelectedIndexChanged" />
    <telerik:RadComboBox ID="States" runat="server" AutoPostBack="True" EnableLoadOnDemand="true" OnItemsRequested="States_ItemsRequested" />
  2. Dimitar Terziev
    Dimitar Terziev avatar
    1266 posts

    Posted 10 May 2012 Link to this post


    In order to force a request for items whenever the second RadComboBox is opened, the OnClientDropDownOpening event should be handled with the following implementation of the event handler function:
    function OnClientDropDownOpening(sender, args) {
          if (sender.get_items().get_count() > 0)
              sender.requestItems("", false);

    Dimitar Terziev
    the Telerik team
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