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

Hi,

The DataGrid does support or response to Custom Font set Using the ExportFont Attribute. But when a contentTemplate is used and a label control is place in it. The font shows on the label but not on the Header or Content of the Grid.

The DataGrid has the ability to add custom controls to the cell via Template columns; however, the contents of the cell are always visible and there is no way to distinguish between editing and display modes like you can with the type data columns. Furthermore, it may be desirable to create custom column types as the reusability would be easier than using a template or a template selector.

Currently, the DataGrid columns are public and unsealed; however, much of their internals are marked as internal. For example, overriding the CreateCellArranger method would allow custom editor types when the cell is edited. This would require exposing the CellArranger base classes as well.

Please mark more of the internals as public so that truely custom DataGridColumns can be created.

To reproduce:

Step 1 - File > New > LoadOnDemandCollection Demo

Follow the LoadOnDemandCollection documentation https://docs.telerik.com/devtools/xamarin/controls/datagrid/load_on_demand#loadondemandcollection

Step 2 - Deploy to UWP

=> Observe the DataGrid will be stuck in busy state after the initial set of items load

Currently in 2019 R2 and earlier, the "options" button at the bottom of the filtering UI allows the user to rearrange and toggle the visibility of columns in the DataGrid.

I request to have a property or setting on the DataGrid or the DataGridColumn that will prevent the user from changing the visibility or ordering of columns. from that UI (just like you can prevent user filtering or user sorting)

 When defining a Date column like

<tdg:DataGridDateColumn PropertyName="ExpiryDate" HeaderText="Expiry"/>

and binding data with a type with Nullable datetime

public System.DateTime? ExpiryDate
{
   get { return _expiryDate; }
   set { SetProperty(ref _expiryDate, value); }
} 

We get an exception

Is there a workaround?

Thanks 

in UWP and using Telerik UI Xamarin R3 2018 got (while Building it):

1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816: Loading assembly "C:\Program Files (x86)\Progress\Telerik UI for Xamarin R3 2018\Binaries\UWP\Telerik.XamarinForms.DataGrid.dll" failed. System.TypeLoadException: Could not load type 'Xamarin.Forms.Xaml.XamlResourceIdAttribute' from assembly 'Xamarin.Forms.Core, Version=2.0.0.0, Culture=neutral, PublicKeyToken=null'.
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.ModuleHandle.ResolveType(RuntimeModule module, Int32 typeToken, IntPtr* typeInstArgs, Int32 typeInstCount, IntPtr* methodInstArgs, Int32 methodInstCount, ObjectHandleOnStack type)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.ModuleHandle.ResolveTypeHandleInternal(RuntimeModule module, Int32 typeToken, RuntimeTypeHandle[] typeInstantiationContext, RuntimeTypeHandle[] methodInstantiationContext)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Reflection.RuntimeModule.ResolveType(Int32 metadataToken, Type[] genericTypeArguments, Type[] genericMethodArguments)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Reflection.CustomAttribute.FilterCustomAttributeRecord(CustomAttributeRecord caRecord, MetadataImport scope, Assembly& lastAptcaOkAssembly, RuntimeModule decoratedModule, MetadataToken decoratedToken, RuntimeType attributeFilterType, Boolean mustBeInheritable, Object[] attributes, IList derivedAttributes, RuntimeType& attributeType, IRuntimeMethodInfo& ctor, Boolean& ctorHasParameters, Boolean& isVarArg)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeModule decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes, Boolean isDecoratedTargetSecurityTransparent)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeAssembly assembly, RuntimeType caType)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Reflection.RuntimeAssembly.GetCustomAttributes(Type attributeType, Boolean inherit)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Attribute.GetCustomAttributes(Assembly element, Type attributeType, Boolean inherit)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Attribute.GetCustomAttribute(Assembly element, Type attributeType, Boolean inherit)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at System.Reflection.CustomAttributeExtensions.GetCustomAttribute[T](Assembly element)
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets(1203,5): error MSB3816:    at Microsoft.Build.Tasks.ProcessResourceFiles.ReadAssemblyResources(String name, String outFileOrDir)
1>C:\Program Files (x86)\Progress\Telerik UI for Xamarin R3 2018\Binaries\UWP\Telerik.XamarinForms.DataGrid.dll : error MSB3103: Invalid Resx file. String reference not set to an instance of a String.
1>C:\Program Files (x86)\Progress\Telerik UI for Xamarin R3 2018\Binaries\UWP\Telerik.XamarinForms.DataGrid.dll : error MSB3103: Parameter name: suffix

Tried to find a similar reported issue but none-is-found...

After first appearing on screen, the DataGrid will cause a NullReferenceException when navigating away. Also occurs if you have a DataGrid in a RadTabView and you switch to another tab.

Same code works on UWP, Android. Crashes on iOS.

XAML:

            <tdg:RadDataGrid x:Name="grid"
                             ItemsSource="{Binding Parts}"
                             HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
                             IsVisible="{Binding ShowData}"
                             StyleClass="TelerikTheme"
                             AlternateRowBackgroundStyle="{StaticResource DefaultDataGridAlternatingRowStyle}"
                             GroupHeaderStyle="{StaticResource DefaultDataGridGroupHeaderStyle}"
                             AutoGenerateColumns="False"
                             SelectionMode="None"
                             UserEditMode="None">
                <tdg:RadDataGrid.Columns>
                    <tdg:DataGridTextColumn PropertyName="PrimaryId"
                                            HeaderText="Primary ID"
                                            CanUserFilter="False"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridTextColumn PropertyName="SecondaryId"
                                            HeaderText="Secondary ID"
                                            CanUserFilter="False"
                                            IsVisible="False"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridDateColumn PropertyName="Start"
                                            HeaderText="Start"
                                            CanUserFilter="False"
                                            CellContentFormat="{}{0:MM/dd/yy hh:mm:ss tt}"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridDateColumn PropertyName="End" 
                                            HeaderText="End" 
                                            CanUserFilter="False"
                                            IsVisible="False"
                                            CellContentFormat="{}{0:MM/dd/yy hh:mm:ss tt}"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridNumericalColumn PropertyName="ShiftNum" 
                                                 HeaderText="Shift #" 
                                                 CanUserFilter="False"
                                                 IsVisible="False"
                                                 HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                                 CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridNumericalColumn PropertyName="ShiftHr" 
                                                 HeaderText="Shift Hour" 
                                                 IsVisible="False"
                                                 HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                                 CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridNumericalColumn PropertyName="ShiftMins" 
                                                 HeaderText="Shift Minutes" 
                                                 CanUserFilter="False"
                                                 IsVisible="False"
                                                 HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                                 CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridTextColumn PropertyName="Line" 
                                            HeaderText="Line" 
                                            CanUserFilter="False"
                                            IsVisible="False"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridTextColumn PropertyName="Station" 
                                            HeaderText="Station"
                                            CanUserFilter="False"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridTextColumn PropertyName="Status" 
                                            HeaderText="Status"
                                            CanUserFilter="False"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                    <tdg:DataGridTextColumn PropertyName="Description" 
                                            HeaderText="Description" 
                                            CanUserFilter="False"
                                            IsVisible="False"
                                            HeaderStyle="{StaticResource DefaultDataGridColumnHeaderStyle}"
                                            CellContentStyle="{StaticResource DefaultDataGridTextCellStyle}" />
                </tdg:RadDataGrid.Columns>
            </tdg:RadDataGrid>

Exception:
2018-10-22 14:56:01.776266-0400 Dynimetrics.iOS[9217:125873] 
Unhandled Exception:
System.NullReferenceException: Object reference not set to an instance of an object
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].UpdateTabStop () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:159 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Xamarin.Forms.Platform.iOS.IVisualElementRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x0000c] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:142 
  at Telerik.XamarinForms.Common.RadPlatform.RetireRenderer (Xamarin.Forms.VisualElement visualElement) [0x0001a] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Telerik.XamarinForms.Common.iOS.RadViewContainer.ClearContainer () [0x00075] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Telerik.XamarinForms.Common.iOS.RadViewContainer.Dispose (System.Boolean disposing) [0x0000a] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Foundation.NSObject.Dispose 
() [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Telerik.XamarinForms.PrimitivesRenderer.iOS.ScrollViewRenderer.RetireViewContainer (Telerik.XamarinForms.Common.iOS.RadViewContainer viewContainer) [0x00004] in <c4c4f7bc21d74b21927d9e243e48a659>:0 
  at Telerik.XamarinForms.PrimitivesRenderer.iOS.ScrollViewRenderer.OnElementContentChanged () [0x0000c] in <c4c4f7bc21d74b21927d9e243e48a659>:0 
  at Telerik.XamarinForms.PrimitivesRenderer.iOS.ScrollViewRenderer.OnElementDetached (Telerik.XamarinForms.Primitives.RadScrollView oldElement) [0x00032] in <c4c4f7bc21d74b21927d9e243e48a659>:0 
  at Telerik.XamarinForms.Common.iOS.IosRendererBase`2[S,T].OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs`1[TElement] e) [0x00016] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x00122] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRen
derer.cs:259 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x0008c] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:340 
  at Xamarin.Forms.Platform.iOS.ViewRenderer`2[TView,TNativeView].Dispose (System.Boolean disposing) [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\ViewRenderer.cs:84 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:69 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:37 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:331 
  at Foundation
.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:69 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:37 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:331 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:69 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x0000
0] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:37 
  at Xamarin.Forms.Platform.iOS.PageRenderer.Dispose (System.Boolean disposing) [0x00070] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Renderers\PageRenderer.cs:164 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.DisposeHelpers.DisposeModalAndChildRenderers (Xamarin.Forms.Element view) [0x00038] in D:\a\1\s\Xamarin.Forms.Platform.iOS\DisposeHelpers.cs:17 
  at Xamarin.Forms.Platform.iOS.Platform.HandleChildRemoved (System.Object sender, Xamarin.Forms.ElementEventArgs e) [0x00006] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Platform.cs:297 
  at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:617 
  at Xamarin.Forms.Element.OnChildRemoved (Xamarin.Forms.Element child) [0x0001f] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:357 
  at Xamarin.Fo
rms.VisualElement.OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\VisualElement.cs:748 
  at Xamarin.Forms.Page.OnInternalRemoved (Xamarin.Forms.VisualElement view) [0x00013] in D:\a\1\s\Xamarin.Forms.Core\Page.cs:380 
  at Xamarin.Forms.Page.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00022] in D:\a\1\s\Xamarin.Forms.Core\Page.cs:358 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0000f] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:288 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00000] in /Library/Framewor
ks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:351 
  at System.Collections.ObjectModel.ObservableCollection`1[T].RemoveItem (System.Int32 index) [0x0002b] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:205 
  at System.Collections.ObjectModel.Collection`1[T].Remove (T item) [0x00027] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/collections/objectmodel/collection.cs:113 
  at Xamarin.Forms.MasterDetailPage.set_Detail (Xamarin.Forms.Page value) [0x0004b] in D:\a\1\s\Xamarin.Forms.Core\MasterDetailPage.cs:44 
  at Dynimetrics.UI.Views.MainPage+<NavigateFromMenu>d__6.MoveNext () [0x0006f] in C:\src\PlantFloorConnect\Dynimetrics\Dynimetrics.UI\Views\MainPage.xaml.cs:54 
--- End of stack trace from previo
us location where exception was thrown ---
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.TaskAwaiter.GetResult () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/1
2.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:113 
  at Dynimetrics.UI.Views.MenuPage+<<-ctor>b__3_0>d.MoveNext () [0x0005d] in C:\src\PlantFloorConnect\Dynimetrics\Dynimetrics.UI\Views\MenuPage.xaml.cs:54 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSAction.cs:178 
--- End of stack trace from previous location where exception was thrown ---
  at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
  at UIKit.UIApplication.Main 
(System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:63 
  at Dynimetrics.iOS.Application.Main (System.String[] args) [0x00001] in C:\src\PlantFloorConnect\Dynimetrics\Dynimetrics.UI.iOS\Main.cs:17
2018-10-22 14:56:01.780638-0400 Dynimetrics.iOS[9217:125873] Unhandled managed exception:
Object reference not set to an instance of an object (System.NullReferenceException)
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].UpdateTabStop () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:159 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Xamarin.Forms.Platform.iOS.IVisualElementRenderer.SetE
lement (Xamarin.Forms.VisualElement element) [0x0000c] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:142 
  at Telerik.XamarinForms.Common.RadPlatform.RetireRenderer (Xamarin.Forms.VisualElement visualElement) [0x0001a] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Telerik.XamarinForms.Common.iOS.RadViewContainer.ClearContainer () [0x00075] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Telerik.XamarinForms.Common.iOS.RadViewContainer.Dispose (System.Boolean disposing) [0x0000a] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Telerik.XamarinForms.PrimitivesRenderer.iOS.ScrollViewRenderer.RetireViewContainer (Telerik.XamarinForms.Common.iOS.RadViewContainer viewContainer) [0x00004] in <c4c4f7bc21d74b21927d9e243e48a659>:0 
  at Telerik.XamarinForms.PrimitivesRenderer.iOS.ScrollViewRenderer.OnElementContentChanged () [0x0000c] in <c4c4f7bc21d74b
21927d9e243e48a659>:0 
  at Telerik.XamarinForms.PrimitivesRenderer.iOS.ScrollViewRenderer.OnElementDetached (Telerik.XamarinForms.Primitives.RadScrollView oldElement) [0x00032] in <c4c4f7bc21d74b21927d9e243e48a659>:0 
  at Telerik.XamarinForms.Common.iOS.IosRendererBase`2[S,T].OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs`1[TElement] e) [0x00016] in <854ee8369bca461384d3ac3224bfd96a>:0 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x00122] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:259 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x0008c] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:340 
  at Xamarin.Forms.Platform.iOS.ViewRenderer`2[TView,TNativeView].Dispose (System.Boolean disposing) [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\ViewRenderer.cs:84 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.fram
ework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:69 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:37 
  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:331 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:69 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:37 

  at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Dispose (System.Boolean disposing) [0x00058] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementRenderer.cs:331 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose (System.Boolean disposing) [0x0003f] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:69 
  at Xamarin.Forms.Platform.iOS.VisualElementPackager.Dispose () [0x00000] in D:\a\1\s\Xamarin.Forms.Platform.iOS\VisualElementPackager.cs:37 
  at Xamarin.Forms.Platform.iOS.PageRenderer.Dispose (System.Boolean disposing) [0x00070] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Renderers\PageRenderer.cs:164 
  at Foundation.NSObject.Dispose () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSObject2.cs:147 
  at Xamarin.Forms.Platform.iOS.DisposeHelpers.DisposeModalAndC
hildRenderers (Xamarin.Forms.Element view) [0x00038] in D:\a\1\s\Xamarin.Forms.Platform.iOS\DisposeHelpers.cs:17 
  at Xamarin.Forms.Platform.iOS.Platform.HandleChildRemoved (System.Object sender, Xamarin.Forms.ElementEventArgs e) [0x00006] in D:\a\1\s\Xamarin.Forms.Platform.iOS\Platform.cs:297 
  at Xamarin.Forms.Element.OnDescendantRemoved (Xamarin.Forms.Element child) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:617 
  at Xamarin.Forms.Element.OnChildRemoved (Xamarin.Forms.Element child) [0x0001f] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:357 
  at Xamarin.Forms.VisualElement.OnChildRemoved (Xamarin.Forms.Element child) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\VisualElement.cs:748 
  at Xamarin.Forms.Page.OnInternalRemoved (Xamarin.Forms.VisualElement view) [0x00013] in D:\a\1\s\Xamarin.Forms.Core\Page.cs:380 
  at Xamarin.Forms.Page.InternalChildrenOnCollectionChanged (System.Object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x00022] in D:\a\1\s\Xamarin.Forms.Core\P
age.cs:358 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedEventArgs e) [0x0000f] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:288 
  at System.Collections.ObjectModel.ObservableCollection`1[T].OnCollectionChanged (System.Collections.Specialized.NotifyCollectionChangedAction action, System.Object item, System.Int32 index) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:351 
  at System.Collections.ObjectModel.ObservableCollection`1[T].RemoveItem (System.Int32 index) [0x0002b] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/System/compmod/system/collections/objectmodel/observablecollection.cs:205 
  a
t System.Collections.ObjectModel.Collection`1[T].Remove (T item) [0x00027] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/collections/objectmodel/collection.cs:113 
  at Xamarin.Forms.MasterDetailPage.set_Detail (Xamarin.Forms.Page value) [0x0004b] in D:\a\1\s\Xamarin.Forms.Core\MasterDetailPage.cs:44 
  at Dynimetrics.UI.Views.MainPage+<NavigateFromMenu>d__6.MoveNext () [0x0006f] in C:\src\PlantFloorConnect\Dynimetrics\Dynimetrics.UI\Views\MainPage.xaml.cs:54 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00037] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0
x00028] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.TaskAwaiter.GetResult () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:113 
  at Dynimetrics.UI.Views.MenuPage+<<-ctor>b__3_0>d.MoveNext () [0x0005d] in C:\src\PlantFloorConnect\Dynimetrics\Dynimetrics.UI\Views\MenuPage.xaml.cs:54 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state)
 [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 
  at Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/Foundation/NSAction.cs:178 
--- End of stack trace from previous location where exception was thrown ---
  at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:79 
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.0.0.15/src/Xamarin.iOS/UIKit/UIApplication.cs:63 
  at Dynimetrics.iOS.Ap
plication.Main (System.String[] args) [0x00001] in C:\src\PlantFloorConnect\Dynimetrics\Dynimetrics.UI.iOS\Main.cs:17

When using a TemplateCell, selection does not fire on Android. 

Reproducible (use SelectionChanged and SelectionUnit="Row"):

<telerikGrid:RadDataGrid.Columns>
    <telerikGrid:DataGridTemplateColumn HeaderText="Key">
        <telerikGrid:DataGridTemplateColumn.CellContentTemplate>
            <DataTemplate>
                <Grid Padding="0,5">
                    <Label Text="{Binding Key}"
                           VerticalOptions="Center"
                           TextColor="Black" />
                </Grid>
            </DataTemplate>
        </telerikGrid:DataGridTemplateColumn.CellContentTemplate>
    </telerikGrid:DataGridTemplateColumn>
</telerikGrid:RadDataGrid.Columns>


WORKAROUND

Set the DataTemplate content's InputTransparent="True" so that input event is passed through the template to the DataGrid:

<DataTemplate>
    <Grid InputTransparent="True">
        ...
    </Grid>
</DataTemplate>