The OnClientTextChange event is triggered inconsistently in RadComboBox.

Typing custom text in the following RadComboBox and pressing enter does not fire the event:

        <script lang="javascript" type="text/javascript">
            function OnClientTextChange(sender, eventArgs) {
                alert("You typed " + sender.get_text());
            }
        </script>

        <telerik:RadComboBox
            ID="RadComboBox1"
            runat="server"
            AllowCustomText="true"
            OnClientTextChange="OnClientTextChange">
            <Items>
                <telerik:RadComboBoxItem Text="item1" Value="item1" />
                <telerik:RadComboBoxItem Text="item12" Value="item12" />
                <telerik:RadComboBoxItem Text="aaaa" Value="aaa" />
                <telerik:RadComboBoxItem Text="bbbb" Value="bbb" />
                <telerik:RadComboBoxItem Text="AAAA1" Value="AAAA1" />
                <telerik:RadComboBoxItem Text="bbbb1" Value="bbb1" />
                <telerik:RadComboBoxItem Text="item11" Value="item11" />
            </Items>
        </telerik:RadComboBox>

Browser:

Microsoft Edge 44.18362.449.0

Telerik Control:

RadCombobox

Teleri Version:  Version=2017.3.913.45,

Issue:

When a item is selected and a postback is occured, the SelectedValue returns an empty string.

Expected behavior:

The correct SelectedValue should be return.

Thing that have been tried so far:

1: upgrade the telerik to the latest version (2020.114) ---> issue persists

2: set autopostback to "true" problem solved

3: use other browsers (chrome, FireFox, new Version 79.0.309.68 ) issue disappears

Sample code: 

1: aspx

2: code behind

<telerik:RadComboBox runat="server" ID="CB" AllowCustomText="true" HighlightTemplatedItems="true" EnableViewState="false" CheckBoxes="true" EnableLoadOnDemand="true" OnItemsRequested="CB_ItemsRequested" ></telerik:RadComboBox>

In combo box once a value is selected there is no option to clear the selection. We can have an additional button outside the combo box to achieve the same.

This will require some additional coding.

Since this is a regular scenario why can't there be a property within the RadCombo Box that makes clear selection button visible next to the combo box drop-down button and does the task of clearing the selection?

RadCombobox WAI-ARIA improvements 

1. When we have a selection but do not have filtering and custom text:

aria-autocomplete: list ---> Combobox list item
2. When we have selection and filtering: ---> Combobox inline completion list item
aria-autocomplete: both
3. disabled: aria-autocomplete: none 

https://www.w3.org/TR/wai-aria-practices/examples/combobox/aria1.0pattern/combobox-autocomplete-both.html

This error comes up often for this control and workarounds have been discussed and posted.  See below

http://www.telerik.com/forums/radcombobox-error-selection-out-of-range-parameter-name-value 
http://www.telerik.com/forums/selection-out-of-range-excpetion 
http://www.telerik.com/forums/selection-out-of-range-parameter-name-error-need-to-be-able-to-set-values-that-don-t-exist-in-the-combobox 
http://www.telerik.com/forums/selection-out-of-range-parameter-name-value 
http://www.telerik.com/forums/selection-out-of-range-parameter-name-value-radcombobox-in-radgrid
http://www.telerik.com/forums/radcombobox-selection-out-of-range-error 
 

The feature request is the following:

1.  Add an Attribute to the RadComboBox, RadDropdownList (and any other controls that suffer from this issue).

2. Let's call the Attribute   --   AppendIfSelectedValueMissing.

3. This attribute would be a boolean (True / False).  Default is FALSE.

4. If AppendIfSelectedValueMissing=True  then when the value of record is being Databound to a RadComboBox, RadDropDownList, etc.  A check (or Try/Catch) would occur to ensure that the Value exists in the DataSourceList and if it does NOT exist in the list then the SelectedValue would be Appended to the List.  Thus, eliminating the "Selection out of range, Parameter, Value" error.

This occur often because some lists get changed over time; however, the historical data may have a value that is no longer on the list -- thus triggering the error.

For example, let's say we ask for a user's Favorite Color.  Our original list was:
Red, Green, Blue

but for some reason -- management, changing user requirements, etc. the new list is

Red, Orange, Blue

Now, if we DataBind a RadComboBox to a historical record with Green as value, we get the "Selection Out of Range" errror.

What I am proposing is -- if we set the AppendIfSelectedValueMissing = True then 
databinding to a historical record with Green would have the following occur.

List from DB ---   Red, Orange, Blue
SelectedValue --    Green
AppendIfSelectedValueMissing
New List for Ctrl --  Red, Orange, Blue, Green

Thus, the error goes away, the historical data can stay the way it is and the lists can adjust their choices over time.

All good for everyone!!!

Thanks for your consideration. 

"Loading..." text in Combobox with Virtual Scrolling is visible on first set of items loading.
It shows first time "Loading..." text. on scrolling it loads items from PageMethods/WebService but "Loading..." text it not visible i.e. because it is first <LI> item so it is not visible.

Instead of first <LI> item, it  should be at position where it always display while loading more items.

same issue is also in telerik demo website : http://demos.telerik.com/aspnet-ajax/combobox/examples/populatingwithdata/autocompletesql/defaultcs.aspx

Using the client-side requestItems method of a RadComboBox to fire the refresh of it's items(with a call to clearCache before to ensure that the refresh is performed), doesn't always perform the async callback request, sometimes resulting in the "Loading" text being added at the top of the combo's items drop-down and staying there (as the callback to the server is never fired, so it's result never received). 

After quite a bit of trials, I finally managed to figure out that the issue arise when there is an async postback in progress on the page (to refresh an update panel) when requestItems is called.

Stepping through the requestItems call with IE F12 tools, I found that this is due to the fact that the Sys.WebForms.PageRequestManager do not perform callbacks if there is an async postback in progress. I think that the RadComboBox should detect that situation and wait until the end of the async postback to fire it's requestItems callback, otherwise the combo get stuck in the "loading in progress" state, waiting for the end of the callback that will never happens as the PageRequestManager did not start it. Additionally, in F12 Network tab, I can see that there is no request performed for the callback to request the items of the combo-box.

I reproduce the issue with the following steps:
1- Have a page with a RadComboBox, a ScriptManager with partial rendering enabled and an UpdatePanel.
2- In the browser, trigger the async postback to refresh the UpdatePanel
3- From JavaScript, while the async postback is in progress, call the requestItems method of the RadComboBox
4- Open the drop-down of the combo, and you can see the "Loading" text at the top, with the initial list of items. And it stays like this until another call is made to requestItems when there is no async post-back in progress which will actually perform the callback.

We have evaluated your controls for few days for the last 3 years now. And you still dont support check boxes and load on demand. (we keep getting the same response from your forms). There are other companies already do that. If you can include this feature in your future development that will be great. As i have mentioned to your sales team about the team size and the number of license we need but unfortunately this feature is not available so we can not buy your controls. Thanks

I recently upgraded from ASP.NET AJAX 2014 to 2022 and ran into an issue with a RadComboBox. It can be reproduced with this code:

Test.aspx
     <telerik:RadScriptManager ID="scriptManager" runat="server" />
            <telerik:RadComboBox ID="rcb" runat="server" Label="Medication:" AutoPostBack="true"
                Width="250" OnSelectedIndexChanged="rcb_SelectedIndexChanged">
                <Items>
                    <telerik:RadComboBoxItem Text="-- select --" Value="" />
                    <telerik:RadComboBoxItem Text="Benztropine 0.5 mg " />
                    <telerik:RadComboBoxItem Text="Buspirone 10 MG" />
                    <telerik:RadComboBoxItem Text="Haloperidol 100mg/ml" />
                    <telerik:RadComboBoxItem Text="Metaprolol 25 mg" />
                    <telerik:RadComboBoxItem Text="Quetiapin/Seroquel 400 mg" />
                    <telerik:RadComboBoxItem Text="Trazadone 150 mg" />
                    <telerik:RadComboBoxItem Text="Vitamin D2 50,000 units" />
                </Items>
            </telerik:RadComboBox>
            <label>SelectedIndex</label> <asp:Label ID="Label1" runat="server" Text=""></asp:Label>
Test.aspx.cs
protected void rcb_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
{
    Label1.Text = rcb.SelectedIndex.ToString();
    rcb.SelectedIndex = 0;
}
When "Benztropine 0.5 mg " is selected, the SelectedIndex in the selected index changed method is incorrectly set to 0, instead of 1. Selecting any other item in the list results in the correct SelectedIndex. I spent a lot of time debugging the code until I noticed that "Benztropine 0.5 mg " has a space at the end.

I found two workarounds:

1. Trim the trailing space from text.

2. Add values for each item.

This was not an issue with the old 2014 version. Is this a bug or am I missing something?

At the first time requesting data, RadClientDataSource sends multiple requests to the server. All subsequent requests for Paging, Sorting work as expected.