This is in a Maui Embedded Project. Other Telerik Controls are working.
Xaml:
<telerik:RadComboBox AutomationId="staticItemsComboBox">
<telerik:RadComboBox.ItemsSource>
<x:Array Type="{x:Type x:String}">
<x:String>USA</x:String>
<x:String>Uganda</x:String>
<x:String>Ukraine</x:String>
<x:String>Canada</x:String>
<x:String>France</x:String>
<x:String>Italy</x:String>
<x:String>United Kingdom</x:String>
<x:String>China</x:String>
<x:String>Japan</x:String>
</x:Array>
</telerik:RadComboBox.ItemsSource>
</telerik:RadComboBox>StackTrace:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.TypeInitializationException: The type initializer for 'Telerik.Maui.Controls.RadComboBox' threw an exception.
---> System.TypeInitializationException: The type initializer for 'Telerik.Maui.Controls.ComboBoxConstants' threw an exception.
---> System.NullReferenceException: Object reference not set to an instance of an object.
at Telerik.Maui.Controls.ComboBoxConstants..cctor()
--- End of inner exception stack trace ---
at Telerik.Maui.Controls.RadComboBox..cctor()
--- End of inner exception stack trace ---
at System.Reflection.ConstructorInvoker.InterpretedInvoke(Object obj, Span`1 args, BindingFlags invokeAttr)
--- End of inner exception stack trace ---
at System.RuntimeType.CreateInstanceMono(Boolean nonPublic, Boolean wrapExceptions)
at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean wrapExceptions)
at System.Activator.CreateInstance(Type type, Boolean nonPublic, Boolean wrapExceptions)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.Activator.CreateInstance(Type type)
at Microsoft.Maui.Controls.Xaml.CreateValuesVisitor.Visit(ElementNode node, INode parentNode) in D:\a\_work\1\s\src\Controls\src\Xaml\CreateValuesVisitor.cs:line 102
at Microsoft.Maui.Controls.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlNode.cs:line 159
at Microsoft.Maui.Controls.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlNode.cs:line 155
at Microsoft.Maui.Controls.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlNode.cs:line 155
at Microsoft.Maui.Controls.Xaml.RootNode.Accept(IXamlNodeVisitor visitor, INode parentNode) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlNode.cs:line 212
at Microsoft.Maui.Controls.Xaml.XamlLoader.Visit(RootNode rootnode, HydrationContext visitorContext, Boolean useDesignProperties) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlLoader.cs:line 207
at Microsoft.Maui.Controls.Xaml.XamlLoader.Load(Object view, String xaml, Assembly rootAssembly, Boolean useDesignProperties) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlLoader.cs:line 78
at Microsoft.Maui.Controls.Xaml.XamlLoader.Load(Object view, String xaml, Boolean useDesignProperties) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlLoader.cs:line 53
at Microsoft.Maui.Controls.Xaml.XamlLoader.Load(Object view, Type callingType) in D:\a\_work\1\s\src\Controls\src\Xaml\XamlLoader.cs:line 49
at Microsoft.Maui.Controls.Xaml.Extensions.LoadFromXaml[StopList](StopList view, Type callingType) in D:\a\_work\1\s\src\Controls\src\Xaml\ViewExtensions.cs:line 37
at TransportACE_Maui.Source.UI.StopList.InitializeComponent() in C:\apacheta_git\TransportACE_HME\TransportACE_Maui\Microsoft.Maui.Controls.SourceGen\Microsoft.Maui.Controls.SourceGen.CodeBehindGenerator\Source_Views_StopList.xaml.sg.cs:line 26
at TransportACE_Maui.Source.UI.StopList..ctor(StopListViewModel viewModel) in C:\apacheta_git\TransportACE_HME\TransportACE_Maui\Source\Views\StopList.xaml.cs:line 13
at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=7.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSiteMain(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite, RuntimeResolverContext context)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2[[Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeResolverContext, Microsoft.Extensions.DependencyInjection, Version=7.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60],[System.Object, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].VisitCallSite(ServiceCallSite callSite, RuntimeResolverContext argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.RuntimeServiceProviderEngine.<>c__DisplayClass4_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
at Microsoft.Maui.MauiContext.WrappedServiceProvider.GetService(Type serviceType) in D:\a\_work\1\s\src\Core\src\MauiContext.cs:line 68
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[StopList](IServiceProvider provider)
at TransportACE.Droid.StopsListMaui.OnCreate(Bundle bundle) in C:\apacheta_git\TransportACE_HME\TransportACE_Maui\Platforms\Android\Source\UITasks\StopsListMaui.cs:line 199
1 Answer, 1 is accepted
Hello Jon,
Thank you for the isolated project.
I reproduced the exception on my side. I have logged an item on your behalf in our public feedback portal. I am sending you a link to the item: Null Reference exception when using Native embedding. You can subscribe to the item to track its progress and get notified by email for any status changes. I have updated your Telerik points as well.
Let me know if I can assist you further.
Regards,
Maria
Progress Telerik
Virtual Classroom, the free self-paced technical training that gets you up to speed with Telerik and Kendo UI products quickly just got a fresh new look + new and improved content including a brand new Blazor course! Check it out at https://learn.telerik.com/.
Rank 1
Hi Pushpalatha,
The behavior happens when native embedding is used. We have this logged here: https://feedback.telerik.com/maui/1604076-null-reference-exception-when-using-native-embedding
Press the follow button to track its progress.
If you do not use native embedding approach the control works as expected.
Hello Jon,
Thank you for the XAML snippet and provided stack trace.
I made a sample project with the code snippet you sent. I noticed that you have not set the x: Name to the ComboBox control. Can you please add this to your project and see if the exception is thrown again?
I am sending you a link to the issue which might occur if the x: Name is not set: Getting a XamlC error when trying to use common xmlns only in XAML without x:Name.
I tried to reproduce it but on my side, the code is buildable and works as expected once the x:Name property is set. I tested it with Visual Studio 2022, NET 7 version, and Telerik Ui for Maui 5.1.0 version. Can you please share more information what is the setup on your side? In addition, I am sending you the project I made. Can you please modify it if I have missed something on my side?
Looking forward to your answer.
Hello Jon,
Please see the attached project in my previous reply. Could you please modify it so I can test the unwanted behavior on my side? With the current information, I can't reproduce the exception.
Looking forward to your reply.
Hello Jon,
Do let us know once you manage to isolate the issue. I will be happy to assist you.