After upgrading to .NET MAUI 10.0.60, the app crashes on Windows with an unhandled exception when RadCollectionView renders items that use a ControlTemplate containing a RadBorder.

Exception:

System.Exception: Keine installierten Komponenten gefunden. (REGDB_E_CLASSNOTREG)
  at ABI.System.Collections.Generic.IListMethods`2.AppendDynamic(...)
  at Microsoft.UI.Xaml.Controls.UIElementCollection.Add(UIElement item)
  at Telerik.Maui.RadBorderExtensions.UpdateBorderContent(Border nativeBorder, IRadBorder border)
  at Telerik.Maui.Handlers.RadBorderHandler.MapContent(...)
  at Telerik.Maui.Controls.RadCollectionViewItemView.OnStyleChanged()
  ...

Root Cause:

MAUI PR #30047 introduced a call to view.Handler?.DisconnectHandler() inside ContentViewHandler.UpdateContent (Windows-only) before re-adding the content to the native panel. This disconnects and invalidates Telerik's RadBorderHandler WinRT object references. When RadBorderExtensions.UpdateBorderContent subsequently calls UIElementCollection.Add, the WinRT interop throws the COM error.

Steps to reproduce:

1. Use MAUI 10.0.60 or later on Windows
2. Place a RadCollectionView with an ItemTemplate or ControlTemplate that contains a RadBorder
3. Run the app and display the collection

Expected: Collection renders correctly.
Actual: App crashes with REGDB_E_CLASSNOTREG.

Versions:

• .NET MAUI: 10.0.60
• Telerik UI for MAUI: 13.2.0 (also reproduced on 13.0.0)
• Platform: Windows (WinUI 3)

Workaround:
Replacing the default ContentViewHandler mapping with a custom implementation that calls platformView.RemoveFromParent() on the native view instead of DisconnectHandler() on the virtual view avoids the crash.

from 11.1.0 version and above the behavior of dropping item changes for my custom scenario.

I have two CollectionView's. one on left has inner collectionview, and one on right. When the inner collectionview has no items, dropping item from the right collectionview to the collectionview with no data cannot be achieved. 

The height of the inner collectionview with no items is 0. 

This works in 11.0.0 version but after 11.1.0 the behavior changes and item cannot be dropped.

when having a document with a text fragment with a transparency, the transparency is not respected. the full color is displayed.

Items do not display after scrolling, navigating to another page, and returning to the page. 

You have to scroll or resize the window and the items appear

having a combobox inside the collectionview, click on the combo to open, then click again on the same location where you clicked to open the combo and exception occurs.

this is the stack trace: 

 at WinRT.ExceptionHelpers.<ThrowExceptionForHR>g__Throw|38_0(Int32 hr)
   at ABI.Microsoft.UI.Input.IGestureRecognizerMethods.ProcessDownEvent(IObjectReference _obj, PointerPoint value)
   at Microsoft.UI.Input.GestureRecognizer.ProcessDownEvent(PointerPoint value)
   at Telerik.Maui.NativeGestureRecognizer.HoldGestureRecognizer_PointerPressed(Object sender, PointerRoutedEventArgs e)
   at ABI.Microsoft.UI.Xaml.Input.PointerEventHandler.Do_Abi_Invoke(IntPtr thisPtr, IntPtr sender, IntPtr e)

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The behavior also happens when using CellEditTemplate and there is RadEntry in it. The SelectionOnFocus does not apply. 

To have a real alternative for wpf, the scheduler should support timeline view. Not for the mobile, but for tablet and browser applications.

In my application i have the resources on the left and de timeline on the top. This is neccesary to migrate to MAUI and be later to Uno or whatsoever

When setting the IsLooping property to "False" through SpinnerStyle property, the infinite looping while scrolling is not disabled.

<ContentPage.Resources>
<Style TargetType="telerik:RadSpinner" x:Key="spinnerStyle">
    <Setter Property="IsLooping" Value="False" />
</Style>
</ContentPage.Resources>

<VerticalStackLayout WidthRequest="300" HorizontalOptions="Center">
    <telerik:RadDateTimePicker x:Name="dateTimePicker"
                                                  SpinnerStyle="{StaticResource spinnerStyle}"
                                                  MinimumDate="2020/01/01"
                                                  MaximumDate="2026/12/31" />
</VerticalStackLayout>