the following exceptions occur when upgrading to Xamarin.Forms v 4.0:

System.NotSupportedException: Unable to activate instance of type Telerik.XamarinForms.DataControlsRenderer.Android.ListView.TemplateCellContainer

System.NullReferenceException: Object reference not set to an instance of an object
  at Telerik.XamarinForms.InputRenderer.iOS.SegmentedControlRenderer.OnElementDetached

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.

If you have a project that has a dependency on: Xamarin.AndroidX.RecyclerView

It will cause a Release build failure due to Telerik.XamarinForms.DataControls using the wrong type in the renderer (AndroidX's RecyclerView instead of v7.Widgets's RecyclerView).

Here is the build error clarifying that it cannot find a `HasStableIds` property/method:

Error Mono.Linker.MarkException: Error processing method: 'System.Void Telerik.XamarinForms.DataControlsRenderer.Android.ItemsControlRenderer::OnElementAttached(Telerik.XamarinForms.DataControls.ItemsControl)' in assembly: 'Telerik.XamarinForms.DataControls.dll' ---> Mono.Cecil.ResolutionException: Failed to resolve System.Void AndroidX.RecyclerView.Widget.RecyclerView/Adapter::set_HasStableIds(System.Boolean)

Reproduce

You can use the attached project to reproduce the problem. Be sure to have the following settings:

• Build in Release configuration
• Set LinkerBehavior to SDK assemblies Only

Workaround

Uninstall Xamarin.AndroidX.RecyclerView

Hi there,

We're struggeling with the radentry control. For login purposes we use one for the password and one for the email. When we set IsPassword=true this does show dots instead of words, but some basic stuff isn't working.

1) The normal entry with IsPassword=true does also hide the suggestion tab that is above the keyboard. We also tried hiding this with other settings but to no result. This control should also hide suggestions since it is a password and we don't want to cache this in any way.

2) When we replace the radentry password field with a xamarin entry password field (so set IsPassword=true on both) then we also get the password fill option. In this case Samsung keypass. I imagine if people are using autofillers such as samsung, google, or something else, that this should also work since i'm stating the field is a password field.

Tested on android with multiple devices.

Thanks in advance!

Martijn

When the SelectionMode of the RadCalendar is Range and you have set a MaxDate - you should not be able to select dates after the MaxDate. However, swipe-selecting cells which are disabled is working. 

Available in the R3 2018 SP release.

When there are only two items in the ItemsSource and users reorder them, the underlying collection is not reordered

Edit: Avalable in R3 2017 SP release.

This can be reproduced using an image with binding for its source.

If the source data has only zero values initially, when the values are changed, the chart does not update its axis range.

Available in minor release 2017.3.927. It will also be available in the R3 2017 SP release.

Available in the R3 2017 release.

I met an issue related to Xamarin.Forms RadListView (telerik component) which occurs only on iOS platform, while working fine on Android.
More details here - http://www.telerik.com/forums/radlistview-not-fitting-on-ios

Multiple selected items that were selected become unselected when being filtered out.

Steps to reproduce:

1 - Select multiple items
2 - Apply filter where some or all of the selected items are filtered out
3 - Remove filter

Observe: 

1 - The items that were previously selected have lost their selection state after returning
2 - Items that were not filtered, or selected while filter was active, retain selection state

When using the __ItemStyle properties of RadListView, they are not being applied if the SelectionMode is set to None. It makes sense that the PressedItemStyle and SelectedItemStyle properties are not used, since they are not applicable if nothing can be selected. However, the ReorderItemStyle in particular should still be used.

Example:

    public class ItemStyleNotAppliedExample : ContentPage
    {
        private readonly ListViewItemStyle WhiteBG = new ListViewItemStyle
        {
            BackgroundColor = Color.White
        };

        private readonly ListViewItemStyle YellowBG = new ListViewItemStyle
        {
            BackgroundColor = Color.Yellow
        };

        private readonly ListViewItemStyle RedBG = new ListViewItemStyle
        {
            BackgroundColor = Color.Red
        };

        private readonly ListViewItemStyle BlueBG = new ListViewItemStyle
        {
            BackgroundColor = Color.Blue
        };

        public ItemStyleNotAppliedExample()
        {
            BackgroundColor = Color.Gray;

            var items = new ObservableCollection<Item>
            {
                new Item("Item 1"),
                new Item("Item 2"),
                new Item("Item 3"),
                new Item("Item 4"),
                new Item("Item 5"),
            };

            Content = new RadListView
            {
                SelectionMode = SelectionMode.None,
                IsItemsReorderEnabled = true,
                ItemsSource = items,
                ItemTemplate = new DataTemplate(typeof(ItemView)),

                ItemStyle = WhiteBG,
                PressedItemStyle = YellowBG,
                SelectedItemStyle = RedBG,
                ReorderItemStyle = BlueBG,
            };
        }

        private class Item
        {
            public string Name { get; }

            public Item(string name)
            {
                Name = name;
            }
        }

        private class ItemView : ListViewTemplateCell
        {
            public ItemView()
            {
                var checkbox = new CheckBox
                {
                    VerticalOptions = LayoutOptions.Center
                };

                var label = new Label
                {
                    VerticalOptions = LayoutOptions.Center
                };

                label.SetBinding(Label.TextProperty, nameof(Item.Name));

                View = new StackLayout
                {
                    BackgroundColor = Color.Transparent,
                    Orientation = StackOrientation.Horizontal,
                    Children =
                    {
                        checkbox,
                        label
                    }
                };
            }
        }
    }

I have upgraded my Xamarin.Forms to version 4.5 and installed the dependent AndroidX nuget packages.  After upgrading UI for Xamarin to version 2020.1.318.1, I'm getting 3 errors below in my Xamarin Android project that seems to have to do with min SDK version when I try to build:

java/lang/String;Ljava/util/List;)[B :  invalid opcode ba - invokedynamic requires --min-sdk-version >= 26 (currently 13) 

com.android.dx.cf.code.SimException: ERROR in androidx.browser.customtabs.CustomTabsService$1.newSessionInternal:(Landroid/support/customtabs/ICustomTabsCallback;Landroid/app/PendingIntent;)Z: invalid opcode ba - invokedynamic requires --min-sdk-version >= 26 (currently 13)

com.android.dx.cf.code.SimException: ERROR in androidx.browser.trusted.ConnectionHolder.getServiceWrapper:()Lcom/google/common/util/concurrent/ListenableFuture;: invalid opcode ba - invokedynamic requires --min-sdk-version >= 26 (currently 13) 

I'm targeting Android 9 and set the minimum supported SDK to 26.  The error hasn't gone away.

I upgraded to latest Telerik to address a reference issue with AndroidX.RecyclerView but it seems that these new errors are showing up now. 

Is there something I can do to resolve the error or do I just have to wait for the next Telerik UI for Xamarin release?

If we have a ListView with a CheckBox inside the ItemTemplate and the whole ListView is placed in a Popup control, following the next steps:

1. Open the popup

2. Check and uncheck the CheckBox control in any of the items.

3. Click into the popup and then outside to close it.

NullReferenceException is raised on iOS.

Hi Team,

I implemented radcheckbox in my xamarin telerik application. In which i select checkbox and afterword i post some data through webAPI. After completion of posting data i got response from server and my app got crashed and show me following stack trace data,

  at Telerik.XamarinForms.PrimitivesRenderer.iOS.CheckBoxRenderer.OnElementDetached (Telerik.XamarinForms.Primitives.RadCheckBox oldElement) [0x00025] in <f3723b4c1d3f406496717d69142c8f84>:0 

  at Telerik.XamarinForms.Common.iOS.IosRendererBase`2[S,T].Dispose (System.Boolean disposing) [0x0001f] in <81c15264f2164ef79a02e84ed79e8bfd>:0 

  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.14.0.114/src/Xamarin.iOS/Foundation/NSObject2.cs:147 

  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in <612eab01c6f546df983c0637f996b4cd>:0 

  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in <612eab01c6f546df983c0637f996b4cd>:0 

  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in <612eab01c6f546df983c0637f996b4cd>:0 

  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.14.0.114/src/Xamarin.iOS/Foundation/NSObject2.cs:147 

  at Xamarin.Forms.Platform.iOS.VisualElementPackager.OnChildRemoved (Xamarin.Forms.VisualElement view) [0x0003e] in <612eab01c6f546df983c0637f996b4cd>:0 

  at Xamarin.Forms.Platform.iOS.VisualElementPackager.OnChildRemoved (System.Object sender, Xamarin.Forms.ElementEventArgs e) [0x0000f] in <612eab01c6f546df983c0637f996b4cd>:0 

  at Xamarin.Forms.Element.OnChildRemoved (Xamarin.Forms.Element child) [0x00007] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:343 

  at Xamarin.Forms.VisualElement.OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\VisualElement.cs:750 

  at Xamarin.Forms.Layout`1[T].OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in <4542de7f0f544d51b46d63bd15d5f6b5>:0 

  at Xamarin.Forms.Layout.OnInternalRemoved (Xamarin.Forms.View view) [0x00012] in D:\a\1\s\Xamarin.Forms.Core\Layout.cs:464 

  at Xamarin.Forms.Layout.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0002b] in D:\a\1\s\Xamarin.Forms.Core\Layout.cs:427 

  at (wrapper delegate-invoke) <Module>.invoke_void_object_NotifyCollectionChangedEventArgs(object,System.Collections.Specialized.NotifyCollectionChangedEventArgs)

  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00018] in <a1ab7fc4639d4d84af41d68234158b1c>:0 

  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00009] in <a1ab7fc4639d4d84af41d68234158b1c>:0 

  at System.Collections.ObjectModel.ObservableCollection`1[T].RemoveItem (System.Int32 index) [0x00021] in <a1ab7fc4639d4d84af41d68234158b1c>:0 

  at System.Collections.ObjectModel.Collection`1[T].Remove (T item) [0x00027] in <939d99b14d934342858948926287beba>:0 

  at Xamarin.Forms.Layout.OnInternalAdded (Xamarin.Forms.View view) [0x0000b] in D:\a\1\s\Xamarin.Forms.Core\Layout.cs:451 

  at Xamarin.Forms.Layout.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00078] in D:\a\1\s\Xamarin.Forms.Core\Layout.cs:443 

  at (wrapper delegate-invoke) <Module>.invoke_void_object_NotifyCollectionChangedEventArgs(object,System.Collections.Specialized.NotifyCollectionChangedEventArgs)

  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00018] in <a1ab7fc4639d4d84af41d68234158b1c>:0 

  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00009] in <a1ab7fc4639d4d84af41d68234158b1c>:0 

My xaml code,

<telerikControls:RadCheckBox IsChecked="{Binding IsSelected, Mode=TwoWay}" HorizontalOptions="Center" VerticalOptions="Center" />

My model class code,

private bool _isSelected;
        public bool IsSelected
        {
            get { return _isSelected; }
            set
            {
                _isSelected = value;
            }
        } 

Version information,

Xmarin form version : 4.1.0

Telerik UI version : 2019.2.802.1

iOS version 12.2