Last Updated: 31 Aug 2021 13:12 by Tom

When using a RadListview with a Grid or a Stack Layout in iOS I get the following exception. I haven't tested using the stacklayout outside of the RadListView nor have I tested it outside of the ItemTemplateSelector

Telerik.XamarinForms.Common.NotRegisteredRendererException: There is no renderer registered for the specified type: Xamarin.Forms.Grid
It works fine on Android. Below is the xaml I'm using.

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns=""
            <DataTemplate x:Key="NonDivisibleTemplate">
                    <StackLayout Orientation="Vertical" Padding="10" Spacing="0" BackgroundColor="Yellow" InputTransparent="True" Unfocused="StackLayout_Unfocused">
                        <Label Text="{Binding ItemText}"/>
            <DataTemplate x:Key="DivisibleTemplate">
                    <StackLayout Orientation="Vertical" Padding="15" Spacing="0" BackgroundColor="White" Unfocused="StackLayout_Unfocused">
                        <Label Text="{Binding ItemText}" FontSize="Large" HorizontalTextAlignment="Center"/>
                        <Label Text="{Binding ItemText}" FontSize="Small" FontAttributes="Italic" TextColor="Gray"/>

                NonDivisibleTemplate="{StaticResource NonDivisibleTemplate}"
                DivisibleTemplate="{StaticResource DivisibleTemplate}" />

    <StackLayout VerticalOptions="StartAndExpand">
        <!-- Place new controls here -->
        <views:FloatingLabelEntry EntryText="{Binding EntryText}" Margin="20" BackgroundColor="Yellow" PlaceholderText="{Binding PlaceholderText}"/>
        <Entry TextChanged="Entry_TextChanged" BackgroundColor="AliceBlue" Margin="20"/>
        <telerikDataControls:RadListView x:Name="listView" ItemsSource="{Binding ListItems}" ItemTemplateSelector="{StaticResource MyTemplateSelector}" SelectionMode="Single" IsItemSwipeEnabled="False" >
            <!--<Grid Margin="0"
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="*" />
                    <StackLayout Orientation="Horizontal" HorizontalOptions="FillAndExpand">
                        <Label BackgroundColor="#2474d2"
                       Text="Mark as read"
                       VerticalTextAlignment="Center" />
                        <Label Grid.Column="2"

Last Updated: 27 Aug 2021 09:10 by ADMIN

If you download the pdf document from the internet, save it to the device and try to show it inside PdfViewer, it will not be loaded on Xiaomi phones with MIUI 12.1. and above.

Users report similar issues with downloaded files on MIUI devices, here are a few discussions on the matter:

It seems that's the same reason for the PdfViewer not showing downloaded pdf files as it properly shows pdf documents added as embedded resource to the solution.

Last Updated: 25 Aug 2021 06:53 by ADMIN
Created by: Mark
Comments: 4
Category: UI for Xamarin
Type: Feature Request
Would like an alternative date picker.  This would allow you to choose a date from a monthly calendar instead of scrolling month, date, or year.  It would be similar to the web version.
Last Updated: 07 Jun 2021 06:09 by Niko

Hi telerik team,

I know, my case is very specific, but I got this Bug and need to fix it somehow.

About: I have a RadSideDrawer in which I have a Collection View in which Header I have a Carousel View. When I rotate the phone in landscape mode the items are resized. After rotate back to portrait they are resized, but a lot of space appeare between them. So the layout is somekind wrong calculated. 
This only occure in this combination on iOS. If I remove the RadSideDrawer it works, if I remove the Collection View it also works, but both together not.

Reprosteps: Create a view with carousel embedded into the header of collection view embedded in to RadSideDrawer. (see attachment)
Rotate to landscape, rotate back to portrait mode.

System information:
xamarin telerik ui: 2021.1.119.4

If you have a workarround for me, I will be very happy. Somehow to trigger a recalculation might help. I tryed set some InvalidateMeasure and ForceLayout but it didn't help. Either it don't work ot I apply it wrong. 
Any help is welcome!

Best regards,

Last Updated: 07 Apr 2021 13:18 by ADMIN


I had developed an Xamarin application, in a modal I open a PdfViewer.

PdfViewerPage pdfViewer = new PdfViewerPage(item.IdAllegato, item.Path, item.FlagScaricabile);


I assign a url to the PdfViewer source.

pdfViewer.Source = new Uri(uri);
Everything is fine in debug mode but when I publish the app on android the PdfViewer show "an error occurred while loading the document" with all pdf.
Last Updated: 02 Mar 2021 06:54 by ADMIN
Created by: Jason
Comments: 1
Category: ListView
Type: Bug Report

Hello, could you provide some guidance about the following situation....


I have a scenario using the RadListView that implements a PropertyGroupDescriptor for a property attached to my ObservableCollection<T>, where the property that it is monitoring is string value.  The dataset is designed that it may have only one grouping before an item is selected them the dataset will have two different groupings.  One the data changes, the ListView updates to show that there are two different groups but the group header doesn't change and neither does the cell content.  If I click on the GroupHeader of the new section, then it updates to reflect the change in data.  Is there a way to get the data to change in the Listview with some kind of Refresh so it stays up to date with the data.

Seeing it on iOS right now.



Last Updated: 02 Mar 2021 06:49 by ADMIN

When I update Telerik.UI.for.Xamarin to v2021.1.119.1, I got following error:


Unable to resolve dependency 'Telerik.UI.for.Xamarin.Documents.Spreadsheet.FormatProviders.Xls'. Source(s) used: '', 'Telerik', 'Microsoft Visual Studio Offline Packages'.


Could you help to take a look? Thanks

Last Updated: 25 Jan 2021 11:59 by ADMIN
Created by: Vardan
Comments: 4
Category: UI for Xamarin
Type: Bug Report

Hi folks.


I am using the rad list view with grouping in my application. There are some cases when the list has empty groups (That's ok because according to the application's logic I can move items between groups). The problem is that the empty group it's not actually "Empty". It has a blank item which is not desirable behavior for me. I have a list view "item tapped" event which navigates the user to the details screen and when I tap on the empty group's item the application throws an exception because the list item is blank. I have attached a sample app according to this example and GIF files showing the issue.


Steps To Reproduce


  1. Download the zip file
  2. Open The app
  3. Add necessary Telerik dlls (Can't send dlls with the sample because of size)
  4. Tap on empty item


    1. Xamarin Forms
    2. Telerik Controls 2020.3 (latest)
    3. IDE Visual studio 2019


    Last Updated: 14 Dec 2020 08:38 by ADMIN
    Created by: Pavel R. Pavlov
    Comments: 18
    Category: SideDrawer
    Type: Feature Request
    Currently only Views can be hosted in the MainContent. If users can host Pages the RadSideDrawer could be used as root navigation component. This will allow customers to define the RadSideDrawer once throughout the application.
    Last Updated: 05 Dec 2020 20:13 by Mehdi
    Hi, I am getting NullReferenceException when trying to set AppointmentsSource for RadCalendar (version 2020.3.916.1) in my page, however, it is set and displayed successfully in the Android project.
    Last Updated: 19 Nov 2020 13:20 by Chris

    System.MissingFieldException: Field not found: Telerik.XamarinForms.SkiaSharp.SkiaDocumentView.purePainter Due to: Could not parse field signature 0a00031b due to: Could not resolve type with token 0100014e from typeref (expected class 'Telerik.XamarinForms.SkiaSharp.DocumentView.SkiaDocumentPurePainter' in assembly 'Telerik.XamarinForms.SkiaSharp, Version=2020.3.1106.460, Culture=neutral, PublicKeyToken=null') assembly:Telerik.XamarinForms.SkiaSharp, Version=2020.3.1106.460, Culture=neutral, PublicKeyToken=null type:Telerik.XamarinForms.SkiaSharp.DocumentView.SkiaDocumentPurePainter member:(null)
      at Telerik.XamarinForms.PdfViewer.RadPdfViewer.UpdatePresenter () [0x00037] in <bd15b7ab3df742a5908d5d151a9a58d8>:0
      at Telerik.XamarinForms.PdfViewer.RadPdfViewer..ctor () [0x00048] in <bd15b7ab3df742a5908d5d151a9a58d8>:0
      at OnaMobile.Views.PdfViewPage.InitializeComponent () [0x00012] in C:\Users\chris\Work\ONAMA\onama-mobile-app\OnaMobile\OnaMobile\obj\Debugetstandard2.0\Views\PdfViewPage.xaml.g.cs:22
      at OnaMobile.Views.PdfViewPage..ctor () [0x00008] in C:\Users\chris\Work\ONAMA\onama-mobile-app\OnaMobile\OnaMobile\Views\PdfViewPage.xaml.cs:19
      at OnaMobile.ViewModels.ResourcesPageViewModel.OpenResourceAsync (OnaMobile.OnlineResources.ResourceLink resource) [0x001ac] in C:\Users\chris\Work\ONAMA\onama-mobile-app\OnaMobile\OnaMobile\ViewModels\ResourcesPageViewModel.cs:186

    iOS SDK 14.1, ARM64. Happens regardless of Linker Behavior setting.

    The page itself has nothing in its code-behind other than the default constructor calling InitializeComponent(). In the XAML, the RadPdfViewer control is in a two-row, one-column grid, where it is in the second row:

    <Grid VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" ColumnSpacing="0" RowSpacing="0">
            <RowDefinition Height="60" />
            <RowDefinition Height="*" />
        <Frame Grid.Row="0"><!-- ... --></Frame>
        <pdf:RadPdfViewer Grid.Row="1" HorizontalOptions="Fill" VerticalOptions="FillAndExpand" Source="{Binding Source}" />
    The view model has a DocumentSource property Source and implements INotifyPropertyChanged. However the exception occurs before the BindingContext of the page is set to the view model.
    Last Updated: 18 Nov 2020 17:34 by Chris

    Runtime exception: Java.Lang.RuntimeException: Font asset not found Fonts/telerikfont.ttf, when trying to access any page with controls that use telerikfont, like AutoCompleteView, TreeView, etc.

    Last Updated: 05 Nov 2020 07:29 by ADMIN
    Created by: Stefan
    Comments: 2
    Category: UI for Xamarin
    Type: Bug Report

    In Selection Changed method SelectedSeries is always empty.

    Is there other way to get which series is selected?


    Last Updated: 23 Oct 2020 06:54 by ADMIN
    Created by: Robert
    Comments: 7
    Category: DatePicker
    Type: Bug Report

    When RadDatePicker is used in debug/testing modes:


    When running in release mode:





    The border is missing, and the line under the header date as well.


    A coworker reports he can't set the header template at all, but I haven't confirmed that yet).


    The control is defined as follows:


    <telerikInput:RadDateTimePicker WidthRequest="175" BorderColor="#333" BorderThickness="1" ...
    Last Updated: 01 Oct 2020 13:16 by ADMIN

    A few things are missing from Xamarin RadSideDrawer. Here's some we found in Android docs, unavailable on Xamarin Forms (and currently causing us issues that require rethinking the app's workflow, as we really needed a drawer that stays fully locked and cannot be dismissed by the user).





    Last Updated: 01 Oct 2020 12:59 by ADMIN

    if the Flow Direction RTL

    the sort of columns changing each time item source changed when customize HeaderContentTemplates  as a data template


    and if HeaderText ysed instead of customizing label as data template the Arabic letters not shown correctly

    Last Updated: 01 Oct 2020 10:36 by ADMIN
    Created by: Clément
    Comments: 3
    Category: AutoComplete
    Type: Feature Request
    I have a page where many AutoComplete controls are used. Selecting a value in one must select a value in another. We know that this value is selected by setting Text property (through object binding), but by doing this, suggestion view shows up.
    I test many tweaks with ShowSuggestionView property, SuggestMode, or whatever, and there is no proper way to achieve the behavior I want.
    Last Updated: 01 Oct 2020 08:25 by ADMIN
    Created by: Thorsten
    Comments: 11
    Category: AutoComplete
    Type: Feature Request
    Currently it is not possible to initialize the tokens of the autocomplete so the UI shows already selected tokens.
    This is necessary to use the control for a CREATE/EDIT scenario.
    - Create an event (party) and select all the friends from the autocompelte (another issue is that already selected tokens cannot be removed from the suggestion list)
    - Save the event
    - Edit the event => now you would need to see the already selected friends so you can add and remove some
    Last Updated: 29 Sep 2020 07:24 by ADMIN
    Created by: Yana
    Comments: 1
    Category: AutoComplete
    Type: Feature Request
    Last Updated: 29 Sep 2020 07:13 by ADMIN
    Created by: Stefan Nenchev
    Comments: 1
    Category: AutoComplete
    Type: Feature Request
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