Hi!

Content pages that use RadListView will throw

System.TypeLoadException: 'VTable setup of type Telerik.XamarinForms.DataControlsRenderer.Android.ListViewAccessibilityDelegateCompat failed'

This is the code i added in my xaml.

How can i fix this problem?

We had a Xamarin 3 iOS application built using Telerik 2018 components and it was working fine until the recent update in iOS. However, after the iOS update to 15, Xamarin 3 iOS app started crashing. Then we updated our app to Xamarin 5 and were able to successfully compile and run it on an iOS 15 simulator. But the Telerik 2018 controls did not render on screen. So we upgraded Telerik control to 2021 version (trial), and now we are having following error which broke the compilation of the entire project.

you must add a reference to assembly 'netstandard version=2.0.0.0 xamarin

It seems that Telerik 2021 controls have a dependency on netstandard library which is either not supported or cannot be installed from NuGet. 

It would be great if you could help us to resolve this issue. This way we would recover our app from crashes, and purchase the latest updates for Telerik.

We developed a mobile app using Telerik Xamarin components in 2017.

It is all working fine till Apple released IOS 15. Now when we try to open the list view the app just shuts down. The app still works fine till 14.7 version

Any of you had a similar issue or support has a clue. Pls let us know.

{Telerik.Windows.Documents.Spreadsheet.FormatProviders.InvalidDataTypeException: Invalid data passed
  at Telerik.Windows.Documents.Spreadsheet.FormatProviders.DataTableFormatProvider.ValidateDataType

ColumnIndex = 0

CurrentDataType = "System.Double"

ExpectedDataType = "System.String"

RowIndex = 41

error occurs when i add number in the worksheet cell.

ive tried testing  a blank worksheet it works fine.

Hi Team,

I am working in Xamarin Forms. I want to remove the reset option in Telerik RadDataGrid Filter.  I am using Customised Filter View with Two Entry boxes. Referred this below link to achieve custom Filter UI.  Kindly give us the solution to remove the reset button.

Ref LInk: https://docs.telerik.com/devtools/xamarin/controls/datagrid/howto/custom-filtering-ui

Hello, 

im new in Xamarin Forms. I tried to get the Row Values of a selected row in DataGrid. The Problem ist when i try this Knowledge Base Article it shows me null  in the selectedItem Breackpoint. Can someone help me to get this Values?

My MainPage.xaml.cs

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.SqlClient;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Telerik.XamarinForms.DataGrid.Commands;
using Xamarin.Forms;


namespace LagerApp.Portable
{
    public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
            GetArticles();
        }
        

        private void buttonbearbeiten_Clicked(object sender, EventArgs e)
        {
            
        }

        private void buttonNew_Clicked(object sender, EventArgs e)
        {
            popupNew.IsOpen = true;
            ArtNumber.Focus();
            ArtNumber.Text = "";
            WerkNumber.Text = "";
            Description.Text = "";
        }

        private void buttonDelete_Clicked(object sender, EventArgs e)
        {

        }

        private async void GetArticles()
        {
            HttpClientHandler clientHandler = new HttpClientHandler();
            clientHandler.ServerCertificateCustomValidationCallback = delegate { return true; };

            HttpClient client = new HttpClient(clientHandler);
            
            var response = await client.GetStringAsync("https://lagerapp.api.leonhardlang.at/api/Lager/GetArticle");
            var articles = JsonConvert.DeserializeObject<List<Articles>>(response);
            var columns = from c in articles select new { c.Artikelnummer, c.Werk, c.Kommentar };
            DataGrid.ItemsSource = columns;
        }

        private async void btnSave_Clicked(object sender, EventArgs e)
        {
            Articles articles = new Articles()
            {
                Artikelnummer = ArtNumber.Text,
                Werk = WerkNumber.Text,
                Kommentar = Description.Text
            };



            var json = JsonConvert.SerializeObject(articles);
            var content = new StringContent(json, Encoding.UTF8, "application/json");
            HttpClientHandler clientHandler = new HttpClientHandler();
            clientHandler.ServerCertificateCustomValidationCallback = delegate { return true; };


            HttpClient client = new HttpClient(clientHandler);
            
            var result = await client.PostAsync("https://lagerapp.api.leonhardlang.at/api/Lager/CreateArticle", content);

            if (result.StatusCode == HttpStatusCode.OK)
            {
                await DisplayAlert("Information","Erfolgreich angelegt", "Ok");
            }

            GetArticles();
            popupNew.IsOpen = false;
        }
       

        private void btnCancel_Clicked(object sender, EventArgs e)
        {
            popupNew.IsOpen = false;
        }

        private void DataGrid_SelectionChanged(object sender, Telerik.XamarinForms.DataGrid.DataGridSelectionChangedEventArgs e)
        {

            if (e.AddedItems.Count() > 0)
            {
                var selectedItem = e.AddedItems as Articles;

                
                Application.Current.MainPage.DisplayAlert("Info", $"{selectedItem.id}, " +
                    $"{selectedItem.Artikelnummer}, {selectedItem.Werk}, {selectedItem.Kommentar}", "OK");
            }

        }
    }

}

My Class: 

using System;
using System.Collections.Generic;
using System.Text;

namespace LagerApp.Portable
{
   
    public class Articles
    {
        public int id { get; set; }
        public string Artikelnummer { get; set; }
        public string Werk { get; set; }
        public string Kommentar { get; set; }
    }
}

Thank you

Good Day,

Kindly help with the issue below:

I implemented RadAutoCompleteView in my Xamarin.forms application.

It works fine on  Android phones and Android tablets.

it works fine on the IOS tablets but failed on ios phones.

The entry input is displayed on IOS phones but the SuggestionItemTemplate does not display.

Kindly help on this issue as below is the name of the package i installed.

Telerik.UI..for,Xamarin.Lite

On iOS, when  the Selected Item is the last item in the Carousal and that Item is removed from the ObservableCollection, the result is the user can only navigate between 2 carousal items even though there are more. The Dot Indicator clearly shows you have more than 5 items but only the last 2 items can be reached through swiping.

Seen on

Telerik UI - 2021.2.728.1

XForms - 5.0.0.2083

Hello everyone,

I have a question on 'refreshing' chart when data source in updated.

Briefly: is there a fixed refresh rate for RadCartesianChart ?

In deep: in my xamarin forms app I added a RadCartesianChart  with a LineSerie updated as follow

     <telerikChart:LineSeries
                        CategoryBinding="MillisecondsCategory"
                        ItemsSource="{Binding Measures}"
                        Stroke="{StaticResource AccentColor}"
                        ValueBinding="Value" />

The "Measures" are data that I received in real time, therefore  they are constantly updated

 private IList<SensorMeasure> measures;
        public IList<SensorMeasure> Measures
        {
            get => measures;
            set => Set(ref measures, value);
        }

I have two way to add data to "Measures": 1) 100 samples every second 2) one sample every 10 millisecond.
When I add data in the way number one everything seems ok and I see the chart updating itself every second with a 'block' of new data, but if I try the second approach (in order to have a "real" real-time visualization) the chart seems to refresh itself in the same way as first one... that's why I am asking:

are there limits in the refresh rate of RadCartesianChart ? Is there a property that I can set to 'speed up' the refreshing process?

I tested my app only on Android device since I am not able to test on iOs.

Thanks in advance