Visual Studio is Interactable and Becomes Unresponsive When Displaying a Custom Form via UITypeEditor using ShowDialog() in a .NET Core Client-Server approach

[SreemonPremkumarMuthukrishnan]

Environment

Microsoft Visual Studio Professional 2022 (64-bit) - Current
Version 17.13.6

.NET version

.NET80 and .NET90

Did this work in a previous version of Visual Studio and/or previous .NET release?

No response

Issue description

When displaying a custom form for the UITypeEditor using ShowDialog() within the server project of a client-server approach, the form is successfully shown but fails to prevent interaction with Visual Studio. Consequently, Visual Studio becomes unresponsive until the form is closed, at which point responsiveness is restored. This issue is specific to .NET Core and does not occur in .NET Framework.

Code to show the form:

 internal class CustomEditorFormHandler : RequestHandler<CustomEditorFormEndpoint.Request, CustomEditorFormEndpoint.Response>
 {
     public override CustomEditorFormEndpoint.Response HandleRequest(CustomEditorFormEndpoint.Request request)
     {
         CustomControl customControl = (CustomControl)request.CustomControl;
         new CustomEditorForm().ShowDialog();
         return new CustomEditorFormEndpoint.Response();
     }
 }

We would appreciate any guidance or suggestions on resolving this issue, particularly in restricting interactions with Visual Studio and addressing the unresponsiveness.

Demo sample:

CustomControlLibrary_WithSample.zip

Issue replication video:

VS_Interactable_Unresponsive.mp4

Steps to reproduce

1. Open the Designer.
2. Click on the CustomControl and open the Properties window.
3. Open the custom form of the "MyCollection" property (via UITypeEditor).
4. Click randomly within Visual Studio.

Expected Behavior:
Visual Studio should not be interactable and should not become unresponsive, like the .NET Framework.

Observed Behavior:
Visual Studio remains interactable and becomes unresponsive.

Diagnostics

[SreemonPremkumarMuthukrishnan]

Is there any update regarding this issue?

[merriemcgaw]

It is not supported to use ShowDialog() in the server process because the server must never do any UI or try to get input from the user because it freezes Visual Studio.

This blog describes how the server-client breakup should be done.