Product / versions

Telerik UI for .NET MAUI 15.1.0 (also reproduced with 15.0.0)
.NET MAUI 11.0.0-rc.2.26505.5 (SDK 11.0.100-rc.2.26504.105), iOS 26.5 and iOS 27.0 (simulator, Xcode 27.0)
Works with .NET MAUI 11.0.0-rc.1.26451.6; Android is not affected

Symptom
On iOS, any RadBorder, RadEffectsView or RadTemplatedButton whose fill comes from Background (a SolidColorBrush, e.g. Background="Orange") renders with no fill. Setting BackgroundColor instead still works. Since RadTemplatedButtonStyle sets Background, templated buttons lose their fill too.

Root cause (from decompiling both assemblies)

RadBorderHandler.BorderMapper (iOS) maps "BackgroundColor" to MapBackgroundColor, which calls RadBorderExtensions.UpdateBackgroundColor:
tkBorder.BackgroundColor = RadMauiCoreHelper.ToUIColor(border.BackgroundColor);
When only Background is set, border.BackgroundColor is null, so this clears UIView.BackgroundColor.
The "Background" key, inherited from ViewHandler.ViewMapper, runs earlier in the same property pass. UIView.UpdateBackground paints a SolidPaint by setting the same UIView.BackgroundColor, which step 1 then wipes.
Up to MAUI rc.1, Controls remapped "BackgroundImageSource" to handler.UpdateValue("Background"). That ran later in the pass and repainted the brush, which hid the problem. In rc.2 (VisualElement.MapBackgroundImageSourceForControls) the redirect is skipped once "Background" has already run in the bulk pass (PropertyMapperPassScope.IsRedundantBulkPassRedirect), so the overwrite now sticks.

On Android, UpdateBackground and UpdateBackgroundColor both rebuild the same BorderDrawable from the whole IRadBorder, so the order of the keys does not matter there.

Repro

<telerik:RadBorder Background="Orange" HeightRequest="80" CornerRadius="8" />
<telerik:RadTemplatedButton Content="Login" Background="Orange" />

Run on iOS with MAUI 11 rc.2: both are transparent. With BackgroundColor="Orange" they render correctly.

Suggested fix
In the iOS MapBackgroundColor (or UpdateBackgroundColor), do not overwrite the native background when IView.Background is a non-empty paint. Alternatively, resolve both properties in one place, as the Android handler does.

Workaround we use

#if IOS
RadBorderHandler.BorderMapper.AppendToMapping(
    nameof(VisualElement.BackgroundColor),
    static (handler, border) =>
    {
        if (border.Background is SolidPaint)
        {
            Microsoft.Maui.Platform.ViewExtensions.UpdateBackground(handler.PlatformView, border);
        }
    });
#endif

Possibly related (pre-existing, also on rc.1)
TKBorderView derives from MauiView, not LayoutView/ContentView. So UIView.UpdateBackground(null) returns early without clearing UIView.BackgroundColor. If Background goes from a brush to null at runtime while BackgroundColor is null, the old fill stays on screen.

Provide support to display highlight annotation in the PDF Viewer. Currently, the highlight color is displayed but the text is missing.

I want an easy way to style the items in the drop down when in normal and selected state. 

Currently I can use the following approaches:

1. RadComboBoxItem and an implicit style 

2. Using the default ItemTemplate and selecteditemtemplate

3. Using the TelerikTheming.

I am reporting a button-sizing issue in Telerik UI for .NET MAUI RadCollectionView on iOS. A recycled item displays the correct button text but can retain the width allocated for the previous item’s longer text.

Environment

• Telerik UI for .NET MAUI 15.0.0; also reproduced with 14.1.0.
• .NET 10, Microsoft.Maui.Controls 10.0.80.
• Platform: iOS.
• No exception or error code accompanies the layout failure.

Reproduction sample:  CollectionViewButtonSizingRepro.zip 

The sample displays Telerik  RadCollectionView  and the built-in MAUI  CollectionView  side by side. Both use the same item template: Grid → Telerik RadButton, with no button width request. Each collection has independent data.

Telerik uses automatic item length ( ItemLength="-1" ); MAUI uses  MeasureAllItems . There are no custom handlers, manual recycling, or layout workarounds.

Steps to reproduce

1. Launch the sample on iOS. All buttons initially display Download.
2. Tap several buttons in the Telerik pane. Their text changes to Downloaded, requiring a wider button.
3. Scroll those rows completely out of view and continue through untouched Download items. Try both continuous scrolling and scrolling with pauses.
4. Repeat independently in the MAUI pane.

Expected: After recycling, each button is sized for its current text and image.

Actual: In the Telerik pane, a Download button can retain the wider allocation from the previous Downloaded state, leaving incorrect spacing. The same template does not reproduce the issue in the MAUI CollectionView pane. Upgrading to Telerik 15.0.0 does not resolve it.

Earlier diagnostics in our original application showed correct fresh button measurement after rebinding, but a stale arranged width without a corrective child arrangement when the footer’s bounds remained unchanged.

Thanks,

Mingxiao Ye

When a RadPopup's content contains nested ContentViews and the Label's (Formatted)Text is assigned after the popup has been opened (IsOpen = true), the popup does not resize to fit the new content, so the text is clipped. Assigning the same text before opening renders correctly.

Hi Team,

I would like to be able to have client-side filtering/sorting/grouping capabilities for large backend datasets that cannot be entirely loaded on the client.

As it stands now, the DataGrid (and other data components) can only operate on the data that is has in the local DataView. This means that I need to build a custom filtering solution that prefilters/presorts the backend data before paging and loading it into the DataGrid.

To accomplish the "full view", we need a data layer that understands both the UI as well as the backend. The Telerik UI for WPF product has an excellent solution for this, known as the WPF EntityFrameworkCoreDataSource - Overview - Telerik UI for WPF and the WPF DataServiceDataSource - Overview - Telerik UI for WPF.

If such a feature can be added to Telerik UI for MAUI, it would be an excellent bonus for the component suite in data heavy applications.

Thank you,

Peter

Provide cross hair feature similar to kendo -> https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/dataviz/ui/chart/configuration/axisdefaults.crosshair  

the requirement is exactly what you have on the kendo chart crosshair where the horizontal line follows the mouse while the vertical line locks to the nearest datapoint. 

Provide an option to display a chart title and align it to top left, right and center and bottom left, right and center