RadComboBox SelectedValue not updating if selecting item with same text

[Callon Campbell]

I have 2 drop downs publisher and heading. If I change the publisher and  select a heading with  a different value but the same text as the previously selected heading the selected value does not update. But if I select a completely different heading with different text and value it works fine.

Here is my code


function PublisherChanged(combo, eventArqs)
{   
    directories.clearSelection()
    headings.clearSelection();
    directories.clearItems(); 
    headings.clearItems(); 
    directories.requestItems('',false);
    headings.requestItems('',false);
                   
}



  private void PopulateHeadings(string publisherName, string text)
        {
          
            if (publisherName == "") return;
            DataTable data = GetHeadings(publisherName, text);
            bool noResults = false;
            if (data.Rows.Count == 0)
            {
                noResults = true;
                DataRow row = data.Rows.Add();
                row["value"] = "[No Results]";
                row["Id"] = "0";
            }

            headings.DataSource = GetTopN(data, 15);
            headings.DataTextField = "value";
            headings.DataValueField = "Id";
            headings.DataBind();


            if (noResults)
            {
                headings.Items[0].Enabled = false;
            }
         
        }

Is the a bug in the control or am I using the control incorrectly?

[Kalina]

Hello Callon Campbell,

I used the code snippets provided to create a test page and tried reproduce the issue - but unfortunately without success. On my side the RadComboBox updates its selected value correctly - please take a look at this demonstration video. Could you please find the sample attached and give it a try? 

In order to help you we need more information - could you please explain your implementation in more details and send us simplified running page that reproduces the issue?

Can we continue this conversation in the support ticket (ID: 339560) that you have opened?
Thank you in advance.

Greetings,
Kalina
the Telerik team

[Billy]

Did this get resolved? I am having the same issue. I reviewed the linked video, my situation does not have a "show value" button, the second drop down does a post back and that displays the selected value.

<%@ Control Language="vb" AutoEventWireup="false" CodeBehind="Test.ascx.vb" Inherits="NewInnovations.Demographics.Web.Test" %>

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>

<telerik:RadComboBox ID="RadComboBox2" runat="server" EmptyMessage="Select a Person"
    EnableLoadOnDemand="true" AppendDataBoundItems="false" AutoPostBack="true" DataTextField="Name"
    DataValueField="RecordID" ShowMoreResultsBox="true" EnableVirtualScrolling="false"
    OnClientDropDownOpening="onDropDownOpening" OnItemsRequested="RadComboBox2_ItemsRequested"
    MarkFirstMatch="true" CausesValidation="False">
</telerik:RadComboBox>

<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>

<script type="text/javascript">
    function onDropDownOpening(sender) {
        var attributes = sender.get_attributes();
        if (attributes.getAttribute("DefaultItem") == "true") {
            sender.requestItems("", false);
            attributes.setAttribute("DefaultItem", "false");
        } else if (sender.get_items().get_count() == 0) {
            sender.requestItems("", false);
        }
    }
</script>

Imports Telerik.Web.UI

Public Class Test
    Inherits System.Web.UI.UserControl

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If MyBase.IsPostBack = False Then
            'drop down list (selected person)
            RadComboBox2.Attributes.Add("DefaultItem", "true")
            RadComboBox2.Items.Add(New RadComboBoxItem("Billy 1", "1"))
        End If
    End Sub

    Protected Sub RadComboBox2_ItemsRequested(ByVal o As Object, ByVal e As Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs) Handles RadComboBox2.ItemsRequested
        '
        Dim thePeople As New List(Of Object)
        thePeople.Add(New With {.RecordID = 1, .Name = "Billy 1"})
        thePeople.Add(New With {.RecordID = 2, .Name = "Billy 2"})
        thePeople.Add(New With {.RecordID = 3, .Name = "Billy 2"})
        thePeople.Add(New With {.RecordID = 4, .Name = "Billy 4"})
        '
        RadComboBox2.DataSource = thePeople
        RadComboBox2.DataBind()
        '
        e.EndOfItems = True 'stops "MoreResultsBox" from calling this event again
        '
        e.Message = Me.RadComboBox2.Items.Count & " People"
    End Sub

    Private Sub RadComboBox2_SelectedIndexChanged(ByVal o As Object, ByVal e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs) Handles RadComboBox2.SelectedIndexChanged
        Me.Label1.Text = e.Value
    End Sub
End Class

[Kalina]

Hello Billy Hasan,

I used the code provided and created a sample page in order to reproduce the issue with our latest version - Telerik.Web.UI 2010.2.826.20. On my side your code works properly and items with same text are selected correctly - please take a look at this demonstration video.

Let me suggest you download our latest version.

Greetings,
Kalina
the Telerik team

[Billy]

Alright, I figured out what the problem is. You have to do a redirect on the page in order for it to no longer work. Also I am using version 2010.2 929

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" 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></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server"></telerik:RadScriptManager>

        <telerik:RadComboBox ID="RadComboBox2" runat="server" EmptyMessage="Select a Person"
            EnableLoadOnDemand="true" AppendDataBoundItems="false" AutoPostBack="true" DataTextField="Name"
            DataValueField="RecordID" ShowMoreResultsBox="true" EnableVirtualScrolling="false"
            OnClientDropDownOpening="onDropDownOpening" OnItemsRequested="RadComboBox2_ItemsRequested"
            MarkFirstMatch="true" CausesValidation="False">
        </telerik:RadComboBox>

        <asp:Label ID="lblSelectedValue" runat="server"></asp:Label>
    </div>
    </form>
</body>
</html>

<script type="text/javascript">

    function onDropDownOpening(sender) {
        var attributes = sender.get_attributes();
        if (attributes.getAttribute("DefaultItem") == "true") {
            sender.requestItems("", false);
            attributes.setAttribute("DefaultItem", "false");
        } else if (sender.get_items().get_count() == 0) {
            sender.requestItems("", false);
        }
    }

</script>

Imports Telerik.Web.UI

Partial Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If MyBase.IsPostBack = False AndAlso Request("Value") IsNot Nothing Then
            'drop down list (selected person)
            RadComboBox2.Attributes.Add("DefaultItem", "true")
            RadComboBox2.Items.Add(New RadComboBoxItem(Request("Text"), Request("Value")))
            '
            Me.lblSelectedValue.Text = Request("Value")
        End If
    End Sub

    Protected Sub RadComboBox2_ItemsRequested(ByVal o As Object, ByVal e As Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs) Handles RadComboBox2.ItemsRequested
        '
        Dim thePeople As New List(Of Object)
        thePeople.Add(New With {.RecordID = 1, .Name = "Billy1"})
        thePeople.Add(New With {.RecordID = 2, .Name = "Billy2"})
        thePeople.Add(New With {.RecordID = 3, .Name = "Billy2"})
        thePeople.Add(New With {.RecordID = 4, .Name = "Billy4"})
        '
        RadComboBox2.DataSource = thePeople
        RadComboBox2.DataBind()
        '
        e.EndOfItems = True 'stops "MoreResultsBox" from calling this event again
        '
        e.Message = Me.RadComboBox2.Items.Count & " People"
    End Sub

    Private Sub RadComboBox2_SelectedIndexChanged(ByVal o As Object, ByVal e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs) Handles RadComboBox2.SelectedIndexChanged
        Dim url As String = String.Format("Default.aspx?Value={0}&Text={1}", e.Value, e.Text)
        Response.Redirect(url)
    End Sub
End Class

[Kalina]

Hi Billy Hasan,

When you redirect the response - in fact you cause a new page load. This means that you lose the state of the page controls stored at ViewState - which is a normal ASP.NET behaviour.
Let me recommend you revise the approach that you use in your implementation.

Kind regards,
Kalina
the Telerik team