RadComboBox wrong selected value

Question

I face the following problem when i use RadComboBox :

    ddl_contactList.Items.Clear();
    ddl_contactList.DataSource = ContactList.GetContactListsByDep(year, main_code);
    ddl_contactList.DataTextField = "list_desc";
    ddl_contactList.DataValueField = "list_code";
    ddl_contactList.DataBind();
    ddl_contactList.Items.Insert(0, new Telerik.Web.UI.RadComboBoxItem("NewList", "-1"));
    ddl_contactList.SelectedIndex = 0;

  <telerik:RadComboBox ID="ddl_contactList" runat="server" AutoPostBack="True" CausesValidation="False"
            CollapseDelay="0" Culture="ar-EG" ExpandDelay="0" Filter="StartsWith" ItemsPerRequest="10"
            MarkFirstMatch="true" Skin="Outlook" EnableAutomaticLoadOnDemand="True" EmptyMessage="-List name-"
            ShowMoreResultsBox="True" 
            onselectedindexchanged="ddl_contactList_SelectedIndexChanged" AppendDataBoundItems ="true">
    </telerik:RadComboBox>

always the number of items in the combo box is 1 !!! although the datasource contains many items so when i try to get the selected value for any item in any time, i always get -1 !!

How to get the correct selectedvalue ?

I think you should add an item to collection before using it as DataSource... — Marco, Jun 18 '12 at 10:34

Rajesh Subramanian · Answer 1 · 2012-06-18T11:39:22.443

1

Add the NewList item before databinding and add the following attribute to RadComboBox.

Setting AppendDataBoundItems to True preserves the items that are already present in RadComboBox. This lets you bind RadComboBox to multiple data sources or use both unbound and bound modes.

Then add the datasource to the control.

ddl_contactList.Items.Clear();
ddl_contactList.Items.Insert(0, new Telerik.Web.UI.RadComboBoxItem("NewList", "-1"));
ddl_contactList.SelectedIndex = 0;


ddl_contactList.DataSource = ContactList.GetContactListsByDep(year, main_code);
ddl_contactList.DataTextField = "list_desc";
ddl_contactList.DataValueField = "list_code";
ddl_contactList.DataBind();

edited Jun 18 '12 at 11:39

answered Jun 18 '12 at 10:39

Rajesh Subramanian

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when i call it in the (!page.IsPostBack) i get the following client error: `There is no assigned datasource,unable to complete callback request` – Anyname Donotcare Jun 18 '12 at 10:55
have u set AppendDataBoundItems= true – Rajesh Subramanian Jun 18 '12 at 11:42
You can do following method also,protected void RadComboBox1_DataBound(object sender, EventArgs e) { var combo = (RadComboBox)sender; combo.Items.Insert(0, new RadComboBoxItem("Select a country", string.Empty)); } – Rajesh Subramanian Jun 18 '12 at 11:43
http://www.telerik.com/help/aspnet-ajax/combobox-insert-default-item-when-databinding.html – Rajesh Subramanian Jun 18 '12 at 11:44

score 1 · Answer 2 · answered Jun 21 '12 at 14:04

1

How about adding them individually instead of binding.

var items = ContactList.GetContactListsByDep(year, main_code); 

foreach(var item in items)
{
   ddl_contactList.Items.Add(new RadComboBoxItem(item.list_desc, item.list_code));
}

ddl_contactList.Items.Insert(0, new RadComboBoxItem("NewList", "-1")); 
ddl_contactList.SelectedIndex = 0;

answered Jun 21 '12 at 14:04

Win

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I did that , and it works but when there are many items the `comcbo box` becomes so heavy onloading !! – Anyname Donotcare Jun 22 '12 at 08:17
You might want to consider using OnItemsRequested. It loads combobox items via ajax when user starts typing inside the combobox. http://demos.telerik.com/aspnet-ajax/combobox/examples/populatingwithdata/autocompletesql/defaultcs.aspx – Win Jun 22 '12 at 14:01

RadComboBox wrong selected value

2 Answers2