ASP.NET Core 3.0

[Scott]

With this well underway now when might we see some versions that work with the 3.0 preview? Thinking mainly of the grid and, not for this forum, the reporting functionality.

Thanks,

Scott

[Pavlina]

Hello Scott,

Please excuse me for the late response here.

The Telerik UI for ASP.NET Core will fully support .NET Core 3.0 once the official version is released. 

We are actively testing against preview versions, so we'll be ready for it, but we don't have the preview builds available at this time.

Regards,
Pavlina
Progress Telerik

[Scott]

Thank you, Pavlina.

[Tom]

Hi Pavlina

Any idea when me might see some preview builds for this?  We've got a project we're in the middle of switching over to Core 3 that relies heavily on the Telerik controls, this is proving a bit of a blocker for us.

Thanks

Tom

[Viktor Tachev]

Hello Tom,

We are actively working on adding support for Core 3.0, testing various scenarios and fixing the issues that we encounter. We will do our best to provide an internal build that works with a preview version of Core 3 so you can test how the components behave in your environment. 

With that said, I cannot specify an exact time frame when .NET Core 3 will be officially supported as this depends on various factors. Nevertheless, I suggest monitoring the release notes of the internal builds - there will be an entry for 3.0 support when it is available. 


Regards,
Viktor Tachev
Progress Telerik

[Tom]

Thanks Viktor, that's good to know.  We've switched the migration to target Core 2.2 for now, we mistakenly thought Core 3 was coming with VS2019 and that things were further on than they actually are!

[Viktor Tachev]

Hi Tom,

Thank you for getting back to us. Do not hesitate to contact us again if you need further assistance.


Regards,
Viktor Tachev
Progress Telerik

[Milena]

Hello,

We are writing to you to let you know that Telerik UI for Asp.Net Core suite will include support for .Net Core 3.0 preview 3(3.0.100-preview3-010431) in the next official release R2 2019, which is scheduled for the middle of May. 
The good news is that you can test it in advance in the latest internal build.
Any feedback would be greatly appreciated, so let us know if some issues arise when apply the latest Kendo.Mvc.dll to your project and we will address them accordingly.

We are currently aware of a problem that is outside of the scope of Kendo UI, but you might encounter it when using JSON serialization:
https://github.com/aspnet/Announcements/issues/342


Regards,
Milena
Progress Telerik

[Scott]

This is great news, thank you Milena. One further question. My project also uses the Reporting library is that also available for 3.0 testing as well?

 

Thank you,

Scott

[Milena]

Hello,

Reporting team have confirmed that the product works as expected with .Net Core 3.0 Preview 3, so you can upgrade your project and verify how it works on your end.

Regards,
Milena
Progress Telerik

[Scott]

Milena,

I upgraded my app and while the Telerik.Reporting library does not cause any issues what does cause my program to not compile is the Telerik.Reporting.Services.AspNetCore library. With this added via Nuget the compilation will fail with the following message:

ErrorCS0579Duplicate 'Microsoft.AspNetCore.Mvc.ApplicationParts.ProvideApplicationPartFactoryAttribute' attributeASPNetCore3Preview3c:\temp\ASPNetCore3Preview3\ASPNetCore3Preview3\obj\Debug\netcoreapp3.0\ASPNetCore3Preview3.RazorTargetAssemblyInfo.cs16Active

I think there must be something in that referencing some part of 2.2 still. This library is required as it contains the ReportControllerBase that needs to be inherited from for reporting to work in ASP.Net Core.

Any thoughts?

Thanks,

Scott

[Ivan Hristov]

Hi Scott,

I'm a member of the Reporting Team and I was asked by my colleague Milena to provide further insight about .NET Core 3 Preview 3 support by our product.

I would like to apologize about the misunderstanding that happened. When Milena asked us about .NET Core support in Telerik Reporting, I misguidedly answered about the current development stage of our product. The currently available releases of Telerik Reporting are built against .NET Framework 4.0 and .NET Standard 2.0. The assemblies built against .NET Standard 2.0 can be used in .NET Core projects 2.1+. This includes the reporting runtime - i.e. the part that actually processes and renders the reports. We are currently testing the runtime on .NET Core 3.0 Preview 3 desktop projects (WinForms and WPF) and it runs as expected.

However, the officially released REST service implementation in Telerik.Reporting.Services.AspNet.Core project has dependencies on AspNetCore 2.1 and AspNetCore.Mvc 2.1 and this part is to be updated in our next release to support .NET Core 3.0. Microsoft has introduced significant changes to these libraries, making them not backwards-compatible. We are addressing these issues and really believe we will ship Telerik Reporting with REST service working on .NET Core 3.0 Preview 3 in our R2 2019 release which is due May 15th.

You can read more about .NET Core support in Telerik Reporting here:
.NET Core Support
How to implement Telerik Reporting in ASP.NET Core 2.1 MVC

Regards,
Ivan Hristov
Progress Telerik

[Scott]

Hello Ivan,

Thanks for the response. A little disappointing after spending time on the conversion but I understand completely how this might happen. Best of luck on the REST library, looking forward to using it.

Also, thanks for the great products you folks put out!

Regards,

Scott

[Scott]

So....I can compile successfully compile my application now, but am unable to get reporting to work with it under 3.0. So, to try and work things out, I took the netcore sample that came with the 2019.2 download but was unable to convert it to 3.0 and have it work properly either. Any chance of getting a sample for 3.0 Preview 5 that shows what exactly needs to change? Or at least some thoughts on what I should look into.

Thank you,

Scott

[Peter]

Hello Scott,

I have attached a working sample project for ASP.NET Core 3.0 Preview 5 .We will make this sample public after the ASP.NET Core 3.0 stable release.

Regards,
Peter
Progress Telerik

[Scott]

Outstanding, thank you so much, Peter!

Regards,

Scott

[Abhijit]

Hi Telerik Team,

I installed Visual studio 2019 with .net core 3.0 preview version. I need to migrate MVC project having kendo controls to ASP.NET Core 3.0. I went to telerik site, and install the installer for TelerikUIForAspNetCoreSetup.exe and telerik.ui.for.aspnet.core.2019.2.619.commercial.msi to install this in visual studio, and i am able to do it successfully too.

However, when i choose a new project with template "TelerikUIForAspNetCore". it gives me option for core 2.2 only and not 3.0 and henece i cannot move further. I attach the screenshot too. Please can anyone help me urgently.

 

[Denitsa]

Hello Abhijit,

The Telerik UI for ASP.NET Core will support .NET Core 3.0 once the official version is released. 
We are actively testing against preview versions, so we'll be ready for it. But we don't have the .NET Core 3.0 available in the New Project wizzard at this time.

In previos post there is attached a working sample project for ASP.NET Core 3.0 Preview 5. You could try it, until the offical samples are available. 

Regards,
Denitsa
Progress Telerik

[Abhijit]

Thanks Denitsa for the update.

Please tell us the timeline if scheduled, when it will release? The official .NET Core 3.0 stable version is scheduled for september though.

[Denitsa]

Hello Abhijit,

The support for ASP.NET Core 3.0 to the existing project templates is planned for our R3 2019 release. It is scheduled for the middle of September.

Regards,

Denitsa
Progress Telerik

[Marco]

Hi,

I couldn't find any preview of the release.

Since for every "DataSourceRequest" model binding attempt, this error is risen

System.TypeLoadException: Could not load type 'Microsoft.AspNetCore.Mvc.ModelBinding.Internal.ModelBindingHelper' from assembly 'Microsoft.AspNetCore.Mvc.Core, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. at Kendo.Mvc.Extensions.ValueProviderResultExtensions.ConvertValueTo(ValueProviderResult result, Type type) at Kendo.Mvc.UI.DataSourceRequestModelBinder.TryGetValue[T](ModelMetadata modelMetadata, IValueProvider valueProvider, String modelName, String key, Action`1 action) at Kendo.Mvc.UI.DataSourceRequestModelBinder.CreateDataSourceRequest(ModelMetadata modelMetadata, IValueProvider valueProvider, String modelName) at Kendo.Mvc.UI.DataSourceRequestModelBinder.BindModelAsync(ModelBindingContext bindingContext) at Microsoft.AspNetCore.Mvc.ModelBinding.Binders.BinderTypeModelBinder.BindModelAsync(ModelBindingContext bindingContext) at Microsoft.AspNetCore.Mvc.ModelBinding.ParameterBinder.BindModelAsync(ActionContext actionContext, IModelBinder modelBinder, IValueProvider valueProvider, ParameterDescriptor parameter, ModelMetadata metadata, Object value) at Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider.<>c__DisplayClass0_0.<<CreateBinderDelegate>g__Bind|0>d.MoveNext() --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync() --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker) at Microsoft.AspNetCore.Builder.RouterMiddleware.Invoke(HttpContext httpContext) at EFS.Web.Extensions.ExceptionMiddleware.InvokeAsync(HttpContext httpContext) in C:\temp\repos\3FS\EFS.Web\Infrastructure\Extensions\ExceptionMiddleware.cs:line 24 at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

 

I think older version can't be used in any 3.0 project 

[Denitsa]

Hi Marco,

You could Create New Telerik Project with Grid for .NET Core 3.0. It is available in the latest version of Telerik ASP.NET Core VSExtension.

The created sample project contains DataSourceRequest.

I hope this will help you.  

Regards,
Denitsa
Progress Telerik

[Dave]

Hello,

Out of the box, using the 'Telerik UI for ASP.NET Core' -> Create New Telerik Project (Grid and Menu) in Visual Studio 2019 + .NET Core 3.0 does not appear to work correctly. The project will get created and will build and run correctly, however when I try to add a new View or Controller I will get the attached error. I kept adding libraries that the error was complaining about until it worked, however I'm not sure this was the correct way to go about fixing this (see attached). 

 

Is there a reason the out of the box extension to create a project is not working?

I've submitted a bug regarding this as well. 

 

Thanks,

Dave

[Denitsa]

Hello Dave,

We tried to reproduce the problem by creating new Telerik Project and then following basic Microsoft tutorial. No errors appeared. 

We have released 2019.3.1023 (R3 2019 SP1), which fixes a conflict issue between Telerik.UI.for.AspNet.Core and ASP.NET Core 3.0. You could try it out.

If the probplem remains could you confirm it is not reproducible with ASP.NET Core 2.2, but only with ASP.NET Core 3.0? 

Regards,
Denitsa
Progress Telerik

[John A]

Hi,

After upgrade to .Net core 3.0, Kendo Html grid displays the data as undefined.

I was required to change my controller action (as part of .Net core 3.0 upgrade)From: return Json(datatable..ToDataSourceResult(request)); To: return Json(datatable.AsEnumerable().ToDataSourceResult(request));

As a result of it my controller response changed as mentioned below

Before Upgrade:
Response:{"Data":[{"Id":"bef5a32f-c5f3-4b8c-99be-66a55c54358e","Filename":"Obligations Register monthly update in depth training .ics","FileType":".ics","Folder":"TEST 24-09-19","FileSize":"0.0065

After Upgrade:
{"Data":[{"RowError":"","RowState":4,"Table":[{"Id":"05467393-5338-4497-b570-ac48d35488b0","Filename":"Kndo-GridQuery (1) (1).docx","FileType":".docx","Folder":"Test0811","FileSize":"0.21

 

[Denitsa]

Hi John,

Thank you for sharing your feedback. 

Indeed migrating from ASP.NET Core 2.2 to 3.0 might be a complicated process. Here are the main articles by Microsoft that should be considered when Migrate from ASP.NET Core 2.2 to 3.0  and Breaking changes introduced.

 

Regards,
Denitsa
Progress Telerik

[Denitsa]

Hi John,

We have modified the method ToDataSourceResult() so it could be used with DataTable in ASP.NET Core 3.0 as in  ASP.NET Core 2.2.

It is available in the latest Internal Build (2019.3.1219) and in the next Official Release that is expected in the middle of January 2020.

 

Regards,
Denitsa
Progress Telerik