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RadComboBox events not firing

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ComboBox

This is a migrated thread and some comments may be shown as answers.

Brad asked on 10 Dec 2008, 07:18 AM

I'm trying to get the RadComboBox to work. I've downloaded the "Paging in RadComboBox' Load On Demand" example from http://www.telerik.com/community/code-library/aspnet-ajax/combobox/paging-in-radcombobox-load-on-demand.aspx, which works fine.

Now I want do duplicate this functionality, however I can't seem to get it working (for some reason no client or server events are firing), so I've downloaded the RadControlsAJAXCourseware.pdf courseware to follow the guide step-by-step but onn page 368 step 3 it asks for a folder "\VS Projects\Images\Colors" which I cannot find; there is no folder like this on my system.

I have installed "RadControls 'Prometheus' for ASPNET Q3 2007". Can you point me in the right direction as to any possible reasons why my events don't fire and/or this Colors folder? I'm assumming there will be a simple solution, but for the life of me I can't find it !?!

Thanks.

    
            <%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %> 
        
            <%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %> 
        
            <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
        
            <html xmlns="http://www.w3.org/1999/xhtml" > 
        
            <head runat="server">  
        
                <title>Untitled Page</title> 
        
            </head> 
        
            <body> 
        
                <telerik:RadCodeBlock ID="RadCodeBlock1" runat="server">  
        
                    <script language="javascript" type="text/javascript">  
        
                        function comboContact_OnClientItemsRequesting(sender, eventArgs)  
        
                        {         
        
                            var context = eventArgs.get_context();    
        
                            context["ContactType"] = "xxx";  
        
                        }  
        
                    </script> 
        
                </telerik:RadCodeBlock> 
        
                <form id="form1" runat="server">  
        
                <div> 
        
                    <telerik:RadScriptManager ID="RadScriptManager1" runat="server">  
        
                    </telerik:RadScriptManager> 
        
                    <telerik:RadComboBox ID="comboContact" runat="server" EnableLoadOnDemand="true" OnClientItemsRequesting="comboContact_OnClientItemsRequesting" OnItemsRequested="comboContact_ItemsRequested" ShowDropDownOnTextboxClick="False" 
        
                        ShowToggleImage="True" ItemRequestTimeout="1500" AppendDataBoundItems="True" ShowWhileLoading="False" AutoPostBack="True" > 
        
                            <CollapseAnimation Duration="200" Type="OutQuint" /> 
        
                            <ExpandAnimation Type="OutQuart" /> 
        
                            <ItemTemplate> 
        
                                <table style="width: 250px; text-align: left">  
        
                                    <tr> 
        
                                        <td style="width: 100px;">  
        
                                            <%# DataBinder.Eval(Container.DataItem, "FirstName") %> 
        
                                        </td> 
        
                                    </tr> 
        
                                </table> 
        
                            </ItemTemplate> 
        
                            <HeaderTemplate> 
        
                                <table style="width: 250px; text-align: left">  
        
                                    <tr> 
        
                                        <td style="width: 100px;">  
        
                                            FirstName  
        
                                        </td> 
        
                                    </tr> 
        
                                </table>                               
        
                            </HeaderTemplate> 
        
                    </telerik:RadComboBox> 
        
                </div> 
        
                </form> 
        
            </body> 
        
            </html>

    
            using System;  
        
            using System.Data;  
        
            using System.Configuration;  
        
            using System.Web;  
        
            using System.Web.Security;  
        
            using System.Web.UI;  
        
            using System.Web.UI.WebControls;  
        
            using System.Web.UI.WebControls.WebParts;  
        
            using System.Web.UI.HtmlControls;  
        
            using System.Data.SqlClient;  
        
            using Telerik.Web.UI;  
        
            public partial class _Default : System.Web.UI.Page   
        
            {  
        
                protected void Page_Load(object sender, EventArgs e)  
        
                {  
        
                }  
        
                private DataSet GetAllContacts()  
        
                {  
        
                    DataSet retVal = null;  
        
                    try  
        
                    {  
        
                        using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["mainConnectionString"].ConnectionString))  
        
                        {  
        
                            SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Contact ORDER BY FirstName", conn);  
        
                            DataSet ds = new DataSet();  
        
                            da.Fill(ds);  
        
                            retVal = ds;  
        
                        }  
        
                    }  
        
                    catch (SqlException ex)  
        
                    {  
        
                    }  
        
                    return retVal;  
        
                }  
        
                protected void comboContact_ItemsRequested(object o, RadComboBoxItemsRequestedEventArgs e)  
        
                {  
        
                    //get a ref to the calling combo  
        
                    RadComboBox combo = (RadComboBox)o;  
        
                    string thePasedString = e.Context["ContactType"].ToString();        // /thePasedString/ should = "xxx", right?  
        
                    combo.ClearSelection();  
        
                    combo.DataSource = GetAllContacts();  
        
                    combo.DataValueField = "ContactID";  
        
                    combo.DataTextField = "FirstName";  
        
                    combo.DataBind();  
        
                }  
        
            }

3 Answers, 1 is accepted

answered on 10 Dec 2008, 12:45 PM

Hi Brad,

I tried with your code on my end and it working as expected. ItemRequested event fires when the user types text into the input field or clicks on the drop-down toggle image when the list is empty.

ASPX:

    
             <telerik:RadComboBox ID="RadComboBox1" runat="server"  EnableLoadOnDemand="true" AutoPostBack="True" OnItemsRequested="RadComboBox1_ItemsRequested" > 
        
                        </telerik:RadComboBox>

CS:

    
            protected void RadComboBox1_ItemsRequested(object o, RadComboBoxItemsRequestedEventArgs e) 
        
                { 
        
                    RadComboBox1.DataSource = GetAllContacts(); 
        
                    RadComboBox1.DataValueField = "ProductName"; 
        
                    RadComboBox1.DataTextField = "ProductName"; 
        
                    RadComboBox1.DataBind();  
        
                } 
        
                private DataSet GetAllContacts() 
        
                { 
        
                    DataSet retVal = null; 
        
                        using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["NorthWindConnectionString"].ConnectionString)) 
        
                        { 
        
                            SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Products", conn); 
        
                            DataSet ds = new DataSet(); 
        
                            da.Fill(ds); 
        
                            retVal = ds; 
        
                        } 
        
                    return retVal; 
        
                }

One another suggestion will be to replace RadScriptManager with ScriptManager and see if the ItemRequested event is getting fired.

Thanks
Shinu