Last Updated: 23 Oct 2020 12:05 by ADMIN
Created by: René
Comments: 1
Category: Calendar & Scheduling
Type: Bug Report

Maybe I am over looking something, but I am unable to show the RadCalendar in the Agenda view mode with a dark background color. I have tried setting the background color of the RadCalendar to a dark color and the AgendaViewSettings only seem to allow me to set text colors and not the background. 

We use the control in three modes, DayView, MonthView and AgendaView and only in agenda we can't seem to change the background color.

Last Updated: 23 Oct 2020 07:35 by ADMIN
In Release mode: Clicking on any of the numbers does nothing.

In Debug mode, clicking the numbers works as expected:
Last Updated: 05 Oct 2020 12:07 by ADMIN

When an item in the ItemsSource of a ListView is null, a NullReferenceException will be raised on Android when the items source is loaded to the list view.  Even if a DataTemplateSelector is applied to display a different datatemplate for null items, the app would still crash.

I attached a sample program that demonstrates the issue.  On iOS the app runs fine, but on Android the app crash at launch with a NullReferenceException.


Last Updated: 30 Sep 2020 13:31 by ADMIN

Activating the ItemHold event of an item in a list view requires holding down an item for a while.  On a physical/virtual Android device and a virtual iOS device, this can be done by holding down the mouse/finger lightly on an item for a short period of time.  However, on a physical iOS device (I am using a physical iPhone 6s to test this), holding down the item lightly with my finger won't activate the ItemHold event, and I have to hold the item really hard on the screen in order to activate it (similar to using 3D Touch / Force Touch, and I cannot reliably activate the ItemHold event possibly because my force is sometimes not hard enough).  I noticed this behaviour on the physical iOS device since the ItemHold event got implemented in early 2018.

I created a simple application to demonstrate the issue.  The app displays an alert when the user taps/holds an item in the list view.  On a physical iOS device, holding down an item in the list view requires the user to press the item very hard on the screen.


Last Updated: 26 Sep 2020 05:28 by ADMIN
Last Updated: 04 Sep 2020 17:00 by Brad
Created by: Brad
Comments: 2
Category: DataGrid
Type: Bug Report

If you use a TrueType font for the DataGrid column's OptionsButtonFontFamily, it is not respected and falls back to a default OS font.


The only workaround at this time is to create a custom column HeaderTemplate with a custom options button and hide the default options button.

<dataGrid:RadDataGrid x:Name="dataGrid" ...>
        <dataGrid:DataGridTextColumn x:Name="productNameColumn" PropertyName="ProductName">

                        <Label Text="Name" TextColor="Black"/>

                        <Label FontFamily="MyCustomFont.ttf#MyCustomFont"
                                    TextColor="Orange" HorizontalOptions="End" HorizontalTextAlignment="End" Grid.Column="1">
                                <TapGestureRecognizer Tapped="TapGestureRecognizer_Tapped"/>
                <dataGrid:DataGridColumnHeaderStyle OptionsButtonFontSize="0" FilterIndicatorFontSize="0"/>

In the code-behind, we use reflection to access the column's command context and invoke the options menu via DataGrid command service.

public partial class YourPage : ContentPage
    private readonly MethodInfo generateOptionsTapContextMethodInfo;

    public YourPage()

        this.generateOptionsTapContextMethodInfo = this.dataGrid.GetType().GetMethod(
            BindingFlags.NonPublic | BindingFlags.Instance);

    private void TapGestureRecognizer_Tapped(object sender, EventArgs e)
        if (this.generateOptionsTapContextMethodInfo != null)
            // Get a reference to the column, this is needed to invoke a command
            var context = this.generateOptionsTapContextMethodInfo.Invoke(
                new object[] { this.productNameColumn });

            // Invoke the command service that opens the options button


Last Updated: 04 Sep 2020 07:41 by ADMIN
When you place a Label with TextType set to "Html" inside ListView TemplatedCell, the ListVIew renders only the items currently in the viewport - if you scroll down, the listview is empty. 
Last Updated: 27 Aug 2020 11:12 by Mahmoud
The horizontal scrollviewer is not visualized initially when the column header text is longer than the columns' text. Still, tapping on any item makes it possible to scroll.
Last Updated: 27 Aug 2020 11:10 by Mahmoud
For example: When I enable DataGrid LoadOnDemand it's loading infinitely for a static list of 3 records.
Last Updated: 27 Aug 2020 09:15 by ADMIN
All columns cannot be scrolled with the mouse wheel. Dragging the columns with the mouse kind of works, but extremely slowly, to the point of being unusable; plus, it's not intuitive.
Last Updated: 25 Aug 2020 09:11 by ADMIN

Changing a property on an item that is involved with grouping and sorting and then removing and re-adding the item to the collection results in the list being in an invalid state (e.g. duplicate items, incorrect template, etc.)

Error message can be reproduced on iPhone 11 Simulator iOS 13.6 

[UICollectionView] Invalid update: invalid number of items in section 0.  The number of items contained in an existing section after the update (4) must be equal to the number of items contained in that section before the update (4), plus or minus the number of items inserted or deleted from that section (1 inserted, 0 deleted) and plus or minus the number of items moved into or out of that section (0 moved in, 0 moved out). - will perform reloadData. UICollectionView instance: <TKCollectionView: 0x7f8525b86600; baseClass = UICollectionView; frame = (0 0; 414 725); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x600001232bb0>; layer = <CALayer: 0x6000019b0520>; contentOffset: {0, 0}; contentSize: {414, 453}; adjustedContentInset: {0, 0, 0, 0}; layout: <TKListViewLinearLayout: 0x7f8524f5e400>; dataSource: <Telerik_XamarinForms_DataControlsRenderer_iOS_TKExtendedListView: 0x7f8524f5b590; frame = (0 0; 414 725); layer =
 <CALayer: 0x6000019b03a0>>>; currentUpdate: [UICollectionViewUpdate - 0x7f8526897fc0: old:<UICollectionViewData: 0x6000025f4000> new<UICollectionViewData: 0x6000025f47e0> items:<(


Last Updated: 13 Aug 2020 10:07 by ADMIN
When resizing after cropping an image - this makes the image uncentered of the control, and also lost transformed shape.
Last Updated: 27 Jul 2020 11:01 by ADMIN
When taping outside of the mask, Invalid Input Error Text is not visualized in Regex and Text Masks
Last Updated: 20 Jul 2020 14:23 by ADMIN

All parts of the TreeViewItem (indicator, text, checkbox) are defined as one big template. Therefore customization of only one part of the template still requires retemplating the whole item. 

When retemplating is applied to the treeviewitem and  20+ children in the nodes are loaded, the result is as follow: If you run that on iOS and expand a node you'll see that it crunches the UI for a few seconds and then loads the child nodes, but i also see on our application that it will crash some times and either way gives a bad feel to the UI on iOS

Last Updated: 17 Jul 2020 10:51 by ADMIN

When we call ScrollItemIntoView to scroll to one of the nodes at the bottom of the tree the app will crash with a "Unspecified Error".

I've set it to load 150 nodes into the tree and when you click the "Test" button it will error (using UWP). If you change it to only load 100 nodes or less it should work.

Last Updated: 16 Jul 2020 11:13 by ADMIN
My main problem is that the placement property doesn't seem to work as intended on the Android platform ("Center" only centers the popup vertically. It works on Windows and iOS).
Last Updated: 10 Jul 2020 08:31 by ADMIN
If you try to set/bind Zoom property of the Chart, the specified Zoom level is not taken into account
Last Updated: 30 Jun 2020 14:28 by ADMIN
KeyNotFoundException exception is thrown when the platform type is MacintoshNonSymbolic and the encoding is WinAnsiEncoding.
Last Updated: 30 Jun 2020 08:06 by ADMIN
Created by: Travis
Comments: 6
Category: NumericInput
Type: Bug Report

I have a Xamarin.Forms app, but I only am using it for UWP at the moment. The plan is to have Android and iOS later, but I am having issues with the RadNumericInput (Xamarin.Forms) and how the decimal key is handled.

Here is my XAML

<tkInput:RadNumericInput Grid.Row="4" Grid.Column="1" Value="{Binding Price, Mode=TwoWay}" StringFormat="{}{0:C2}" />

Right now, "Price" will default to 0. The UI will initially show $0.00 because of the StringFormat. That is working fine. When I put focus into the control, I only see 0, that is also fine. The issue is when I try to type a decimal. The value disappears and I see an issue in my Output that says -- Binding: can not be converted to type 'System.Int32'


Example steps:

  • With the value set to 0.00
  • Focus the control -- you will now see just 0
  • Press the decimal key (aka the period key)
  • Notice the error in the Output window in VS and also the control shows nothing at all
  • If you press the decimal key again, you will see two decimals in the control

**** Also, the Version of the Telerik controls I am using is -- 2019.2.603.360. The drop down below doesn't let me choose that version.

Last Updated: 22 Jun 2020 15:39 by ADMIN

On Android,  when the user selects a date on CalendarViewMode.Month mode, the DisplayDateChanged event is fired twice and the displayed date in CalendarViewMode.Day is incorrect. 

Sometimes the display date is 4-6 months ahead/behind or just with one month.

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