Components not visible in VS 2019

[Herald]

Hello

I started a Winforms .net 3.1 project. All Telerik components are not visible in the Toolbox. When I try adding them (Right-clink in General, Chose-items, etc.) I can see all the Telerik components, checked, and when I uncheck-recheck a few nothing happens. The Telerik menu is visible and active in the Extensions menu. 

Also all forms (in designer mode) show this error: "The designer could not be shown for this file because none of the classes within it can be designed. The designer inspected the following classes in the file: The designer could not be shown for this file because none of the classes within it can be designed. The designer inspected the following classes in the file: \r\n NewEmailForm --- The base class 'Telerik.WinControls.UI.RadForm' could not be loaded. Ensure the assembly has been referenced and that all projects have been built." Even though the project is cleaned and rebuild multiple times. When run in dbeug mode, all runs fine without errors. The designer for any form is just not usable.

When trying to add a new RadForm i get and error about "Scenario wizard cannot be launched..." (see attached). I am thinking it cannot load the assembly files, yet everything runs fine when debugging and part of VS2019 seem to be aware of installation.

 

This only happens in a .NET Core (3.1) project. If I do the same on a .NET Framework project all works well.

 

Here are my versions:

- Microsoft Visual Studio Enterprise 2019 / Version 16.6.4
- Microsoft Windows 10 Enterprise / Version 10.0.1.18363 Build 18363
- Telerik UI for Winforms 2020.1.218.310

 

 

Thanks

Herald

 

 

[Dess | Tech Support Engineer, Principal]

Hello, Herald,

The WinForms designer in .NET Core is still in its preview and currently it misses key features like support for libraries of third party vendors. We are closely working with Microsoft to determine the best possible implementation approach. At the moment we cannot provide you with a time estimate for a possible release or preview of the feature. I would recommend you to have a look at the following blog post that Microsoft released on this topic: https://devblogs.microsoft.com/dotnet/windows-forms-designer-for-net-core-released/?fbclid=IwAR2q7fHPZ4RgS8bZwQSnTPjWqpKPOpxzc3j5PmPA-U4qbpF9xk0Iet4h_NE 

I can suggest referring the official Microsoft documentation for details on porting a project built on the full .NET framework to .NET Core: https://docs.microsoft.com/en-us/dotnet/core/porting/  Please bear in mind that the project file format in .NET Core is different so it will be necessary to update the old .csproj files. Microsoft have developed a tool to automate this process: https://github.com/dotnet/try-convert  Since R2 2020 Telerik UI for WinForms suite provides tooling in Visual Studio 2019, via our Visual Studio Extensions, that will convert client projects that use .NET Framework 4.8 (or lower) into .NET Core projects to ease out the migration: https://docs.telerik.com/devtools/winforms/core/net-core-project-converter  

As for the designer, please note that even the Microsoft implementation is still limited and only available as a preview in Visual Studio. If you need to target .NET Core and have complex designers you may consider trying the workaround as explained here: https://github.com/dotnet/winforms/blob/master/Documentation/winforms-designer.md . With this approach you can still target .NET Core and at the same time achieve the design-time experience you are already used to.

Additionally, you can also check some of our resources on this topic:
https://docs.telerik.com/devtools/winforms/core/core-migration 
https://docs.telerik.com/devtools/winforms/core/deploy-application 
https://www.telerik.com/blogs/3-ways-to-deploy-a-winforms-or-wpf-net-core-application

I hope this information helps. If you need any further assistance please don't hesitate to contact me. 

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik

[eliyahu]

I have the same problem.

I want to use a DataGridView control. I started from out-of-box VS 2019 and found that there's no designer support for the control. Then I went to the Telerik site https://www.telerik.com/products/winforms.aspx and found a claim about supporting .NET Core 3.1. I spent a few hours on installing and trying Telerik WinForms controls just to find out that it is even worse than Microsoft. With standard Microsoft, you can open a form and use other components except for the DataGridView. With Telerik, you can't even open a form in the first place. Your claim is misleading, you have to say on your site that the product is limited. I have a long good experience with Telerik and, till now, never ran into a situation of an inaccurate claim on the product page.

 

[Dess | Tech Support Engineer, Principal]

Hello, Eliyahu,

I am really sorry to hear that you were confused by the information on the product page.

Indeed, .NET Core 3.1 is supported by the Telerik UI for WinForms suite and we do provide several builds of our assemblies including for .NET Core 3.1: https://docs.telerik.com/devtools/winforms/installation-and-upgrades/assemblies-version 

As to the Visual Studio designer, it is officially stated in the previously referred blog post by Microsoft what is coming next: https://devblogs.microsoft.com/dotnet/windows-forms-designer-for-net-core-released/?fbclid=IwAR2q7fHPZ4RgS8bZwQSnTPjWqpKPOpxzc3j5PmPA-U4qbpF9xk0Iet4h_NE 

"What’s coming next
- Project resources
- Complete localization
- Inherited dialogs support
- Data binding scenarios
This work is in progress, and you already can see some results in the Visual Studio 16.7 Preview 1 designer.
- Third-party control vendors support
We are working closely with the control vendors such as Progress Telerik, DevExpress and GrapeCity on supporting their controls in the Windows Forms designer in the nearest future for .NET Core and .NET 5 projects. We are also collaborating with ActiPro, Infragistics, and SyncFusion."

Currently, we are working hardly in collaboration with Microsoft to introduce VS designer for the controls in the Telerik UI for WinForms suite. Stay tuned and I strongly believe that we will be able to introduce considerable improvements in this feature in the upcoming releases. 

Should you have further questions please let me know.

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik

[Marc]

@Dess, any update on this?  VS 2019 Preview 16.8.0 Preview 3 is available.

 

When working on a .NET Core 5 WinForm project in the designer, the Telerik tabs are not shown.

Is there a timeline as to when we should expect full functionality?  I appreciate that Microsoft controls the schedule, but I assume that have provided target dates for when features need to be complete.

 

Thanks

 

-marc

[Dess | Tech Support Engineer, Principal]

Hi, Marc,

In order to use the Telerik WinForms designer for .NET Core, it is necessary to:

-         -  Target .NET 5.0

-         -  Install a Telerik WinForms NuGet package, e.g. the AllControls package

-         -  Use Visual Studio 2019 Preview, version 16.8.0 Preview 3

You can also check our documentation article here: https://docs.telerik.com/devtools/winforms/core/design-time

I hope this information helps. If you need any further assistance please don't hesitate to contact me. 

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik

[Patrick]

Hi Dess,

I have created a new Telerik WinForms solution using Visual Studio Community 2019 Preview (16.9.0 Preview 1.0), and targeted .NET 5 as per the instructions in your post.  I also included the latest Telerik NuGet packages based on the documentation that you referenced:

  <ItemGroup>
    <PackageReference Include="UI.for.WinForms.AllControls.Net50" Version="2020.3.1116-hotfix" />
    <PackageReference Include="UI.for.WinForms.AllControls.NetCore" Version="2020.3.1116-hotfix" />
  </ItemGroup>

 

Nevertheless, I am unable to open the designer for RadForm1 as I get the following error:

The designer could not be shown for this file because none of the classes within
it can be designed. The designer inspected the following classes in the file:
RadForm1 --- The base class 'Telerik.WinControls.UI.RadForm' could not be
loaded. Ensure the assembly has been referenced and that all projects have been
built.

 

The call stack trace information indicates the following issues:

Instances of this error (1)

1. Hide Call Stack
at System.ComponentModel.Design.Serialization.CodeDomDesignerLoader.EnsureDocument(IDesignerSerializationManager manager)
at System.ComponentModel.Design.Serialization.CodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager manager)
at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager serializationManager)
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager serializationManager)
at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.DeferredLoadHandler.Microsoft.VisualStudio.TextManager.Interop.IVsTextBufferDataEvents.OnLoadCompleted(Int32 fReload)

 

I would be happy to provide you with the project files if this could help.  Please let me know how to resolve this issue.

 

 

Thanks in Advance,

Patrick

[Dess | Tech Support Engineer, Principal]

Hello, Patrick,    

Telerik UI for WinForms suite officially supports .NET 5: https://www.telerik.com/blogs/dotnet-conf-2020-telerik-ui-for-winforms-wpf-officially-supports-dotnet-5

If you meet the specified requirements for using Visual Studio 2019 v16.9 Preview 1 and Telerik UI for WinForms version HotFix v2020.3.1116-hotfix and you are still experiencing any further difficulties with the designer, it would be greatly appreciated if you can provide a sample project with the problematic form.

You can either upload a sample project in the cloud and provide the link here to download it or open a support ticket with attaching the project there. Thus, we would be able to investigate the precise case and provide further assistance. Thank you in advance for your cooperation.

I am looking forward to your reply.

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik