Last Updated: 21 Jan 2020 07:39 by ADMIN
I have a listview with item templates in a modal popup but it is not visible on iOS simulator. On Android device it is OK.
Last Updated: 01 Nov 2019 11:47 by ADMIN
Created by: Yash
Comments: 0
Category: ListView
Type: Bug Report

Follow this tutorial https://docs.telerik.com/devtools/xamarin/controls/listview/listview-features-load-on-demand#loading-mode-with-collection 

It works on Android and iOS, but on UWP it is defaulting to Explicit mode and clicking the load button crashes the app.

Last Updated: 25 Oct 2019 11:31 by ADMIN

When RadListView is setup to load its items on demand and the LayoutDefinition is GridLayout with SpanCount set to 2 or more, the Footer Template does not take all the width, it expands only to the Width of the first column.

Last Updated: 21 Oct 2019 15:18 by ADMIN

The bug can be reproduced on iOS 13 only. It is not reproducible on earlier versions of iOS. Run the attached project on iOS 13 device or Simulator to reproduce it.

Sometimes when focusing an entry and the onscreen keyboard shows up, the ListView is not scrolled correctly, so the entry is overlapped by the keyboard. The ListView layout appears messed up after that and the scrolling does not behave correctly.

Last Updated: 15 Oct 2019 08:43 by ADMIN
Cell height is not being adjusted to show all the content. the text overflow and it overlap the cell below. It seems that dynamic size is not respected.
Last Updated: 14 Jan 2020 12:59 by ADMIN
With Automatic LoadOnDemand, once all items are loaded and IsLoadOnDemandEnabled is set to false, when I scroll till the end the loading indicator keeps flickering on knowing that no more items are called.
Last Updated: 08 Oct 2019 11:05 by ADMIN
if the swipe content of the cells are buttons, dragging the buttons up and down will keep the swiped cells in the same position of the screen, creating unexpected animations and showing the entire swipe content of the cell.
Last Updated: 08 Oct 2019 10:45 by ADMIN
When swiping a cell, the swipe content of the cell will be shown if the swipe threshold is reached.  On iOS, the swipe content of another cell can be shown immediately by swiping another cell (which is an expected behaviour).  However on Android, when the user swipes another cell, the swipe content of the other cell isn't shown (while the swipe content of the first cell becomes hidden).  The user has to swipe the other cell again to show the swipe content.
Last Updated: 07 Oct 2019 10:08 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: 04 Oct 2019 14:46 by ADMIN
Release 2019.3.1004 (R3 2019 minor release)
GroupHeaderTemplate has a default gray background applied and setting Transparent does not take any effect.
Last Updated: 04 Oct 2019 14:45 by ADMIN
Release 2019.3.1004 (R3 2019 minor release)
When any control (Frame, for example) with applied Margin is placed inside GroupHeaderTemplate of the ListView, the Margin value is not respected on iOS.
Last Updated: 18 Sep 2019 11:49 by ADMIN
Release R3 2019
RadListView item height is not adjusted to fit the content in the cell on iOS 13 Beta.
Last Updated: 05 Sep 2019 08:53 by ADMIN
When you initiate a swipe gesture and the SwipeContentTemplate is shown,  changing the device orientation from portrait to landscape, does not update the ListView layout and the swiped item width is incorrect.
Last Updated: 04 Nov 2019 15:25 by ADMIN
Java.Lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

For example change the IsPullToRefreshEnabled state on button click, when button is pressed several times, exception is throw.
Last Updated: 22 Jul 2019 12:29 by ADMIN
When using DataTemplates on the ListView for Android, items are constantly redrawn when data shown on the template is updated, this is obvious to the user as it flashes and doesn't look great. Note that the native ListView does not do this.
Last Updated: 19 Sep 2019 14:22 by ADMIN


I rolled my app with the ListView out to production and are getting 8+ crashes a day from 140 users with the above issue. I have included a stack trace. I cannot find the steps to reproduce the issue in development. I have rolled back to using the native ListView as this does not crash the app.

Attached is an example project to see what I am doing in general terms, but I have not been able to reproduce this crash in it.

My guess is that a DataTemplate is not being cleaned up properly and when the data behind is changed it attempts to access the control that represented the data in the DataTemplate.


Xamarin caused by: android.runtime.JavaProxyThrowable: System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'Android.Support.V7.Widget.SwitchCompat'.
Java.Interop.JniPeerMembers.AssertSelf(IJavaPeerable self)<9cb01525c8ce48268eb7a54e1b653d67>:0
Java.Interop.JniPeerMembers.JniInstanceMethods.InvokeVirtualVoidMethod(string encodedMember, IJavaPeerable self, JniArgumentValue* parameters)<9cb01525c8ce48268eb7a54e1b653d67>:0
Android.Widget.CompoundButton.set_Checked(bool value)<83e36ed05052486983583851de96589e>:0
Xamarin.Forms.Platform.Android.AppCompat.SwitchRenderer.HandleToggled(object sender, EventArgs e)<e6fe81c4055a4db5bd435b7d12d894e3>:0
at Xamarin.Forms.Switch+<>c.<.cctor>b__14_0 (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue) [0x0001c] in <209f66ed8fe04cb6a815feb8c3b62471>:0
Xamarin.Forms.BindableObject.SetValueActual(BindableProperty property, BindableObject.BindablePropertyContext context, object value, bool currentlyApplying, SetValueFlags attributes, bool silent)<209f66ed8fe04cb6a815feb8c3b62471>:0
Xamarin.Forms.BindableObject.SetValueCore(BindableProperty property, object value, SetValueFlags attributes, BindableObject.SetValuePrivateFlags privateAttributes)<209f66ed8fe04cb6a815feb8c3b62471>:0
Xamarin.Forms.BindingExpression.ApplyCore(object sourceObject, BindableObject target, BindableProperty property, bool fromTarget)<209f66ed8fe04cb6a815feb8c3b62471>:0
Xamarin.Forms.BindingExpression.Apply(bool fromTarget)<209f66ed8fe04cb6a815feb8c3b62471>:0
Java.Lang.IRunnableInvoker.n_Run(IntPtr jnienv, IntPtr native__this)<83e36ed05052486983583851de96589e>:0
at (wrapper dynamic-method) System.Object.31(intptr,intptr)
mono.java.lang.RunnableImplementor.n_run(Native Method)
java.lang.reflect.Method.invoke(Native Method)


Last Updated: 08 Aug 2019 11:58 by ADMIN
Created by: Anthony
Comments: 3
Category: ListView
Type: Bug Report


As the header suggests, Swipe No Longer Works When Offset And Threshold Are Equal, the swipe closes on finger release. This started happening in the latest release, 2019.2.619.1, previously this worked without issue.

This can be replicated in the SDKBrowser by setting the following in Cell Swipe - Interactive Content example:

SwipeOffset="70, 0, 0, 0"

I have only tested this on Android. 




Last Updated: 19 Sep 2019 14:17 by ADMIN

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="http://xamarin.com/schemas/2014/forms"
            <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: 19 Feb 2020 16:13 by ADMIN
Release R1 2020 SP1
Created by: Safan
Comments: 0
Category: ListView
Type: Bug Report
When the ListView has more items, it could be vertically scrolled, however, there is no UI for vertical scrollbar on Android.  The same can be observed with RadTreeView control.
Last Updated: 06 Jun 2019 14:45 by ADMIN
NullReferenceException is thrown when Singleton ViewModel is used
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