We are using List box item scroll into view to scroll to the item selected in the list box. However, the scroll is not working in the Chrome browser in a UHD touch screen laptop device.

Replicate by dragging a RadListBox item vertically in the Drag-and-drop demo, on a mobile device.

 I would like to implement a list picker with item grouping in the destination Asp.Net RadListBox.

Unfortunately the Telerik Asp.net RadListBox control does not seem to support item grouping natively. I have seen a forum post from 2019 that suggests adding custom group items https://www.telerik.com/forums/subheadings-in-radlistbox  We could do this but would prefer a more native solution.

Setting EnableEmbeddedSkins="false" in RadGrid when FilterType="HeaderContext" is not applied to the ListBox (filterCheckList) hence the following error is thrown:

Telerik.Web.UI.RadGrid+RadListBoxShared with ID='filterCheckList' was unable to find an embedded skin with the name 'MY_THEME'   

 

1. Open the demo page linked above.
2. Scroll down to the bottom of the RadListBox using only the mouse wheel.
3. Click on any item (e.g., "USA") to select it.

• The issue does not occur if the user clicks and drags the scrollbar thumb with the left mouse button before selecting an item.
• The issue does not occur if the user clicks the top or bottom navigation arrows on the scrollbar container to scroll.
• The unexpected reset to 0 only triggers when scrolling is performed exclusively via the mouse wheel prior to item selection.

RadListBox allows to declaratively bind the Text and Value properties of the ListItems, e.g:

<telerik:RadListBox runat="server" DataTextField="Text" DataValueField="Id">

Unfortunately, this is not possible for the ImageUrl property.

My Suggestion: please allow to also bind the ImageUrl declaratively as known from other controls, e.g:

<telerik:RadListBox runat="server" DataTextField="Text" DataValueField="Id"
    DataImageUrlField="..."

// and maybe even like this:

    DataImageUrlFormatString="..." DataImageUrlFields="...">

When there are few checkbox items in RadListBox (i.e. there is no scroll bar), checked items cannot be unchecked. The issue is reproducible in iPAD.

The error is observed when an item that is added from the client-side is to be transferred to other RadListBox from a RadListBox that is loading on demand. Unfortunately the control supports such scenario only when that transfer is made from the server side.

I have a few instances where I need OnClientSelectedIndexChanging inorder to stop the listbox selectedIndexChanged event from posting back in certain cases. In those cases I stop it from posting back by setting the e.set_cancel(true);

function CheckForListBoxReorder_OnClientEvent(sender, e) {
    if (ListboxReordered()) {
        alert('Please save changes to the bus order.');
        e.set_cancel(true);
    }
}

This works very nicely, but I'm getting many errors because although it looks like it's still selected to the proper row in the listbox the selectedIndex is now -1.

Issue 1 - Items in ListBox missing and/or cut off.
Issue 2 - Incorrect highlighting
Issue 3 - Moving items sometimes doesn't work
Issue 4 - Scrolling of items scrolls the whole page instead (sometimes)
Issue 5 - Bottom ListBox cut off (Chrome dev tools, iPhone 5/SE)
Issue 6 - Scrolling in ListBox sometimes selects items
Issue 7 - Sometimes items in the Listboxes cannot be selected at all. (Intermittent)

The problem happens when you select an item and then press the down arrow button to move it. The item does not move. If you then press the down arrow button a second time, it does move.