[BUG?] Hot Reload not working in VS Code

[Sorrow-Scarlet]

Overview

Trying to use hot reload, after reading hotreload.md in Docs.

I found that hot reload is not working at all.

Am I using it wrong?

Walkthrough

MewUiHotReload.RequestReload([typeof(MainView)])

• Bind above code to OnMouseEnter event
• Bind above code to Btn OnClick event
• Not bind to any event

MewUI Info

  <ItemGroup>
    <PackageReference Include="Aprillz.MewUI" Version="0.14.0" />
  </ItemGroup>

OS Info

Operating System

• Name: Microsoft Windows 11 Home CN
• Version: 10.0.26100
• Architecture: 64 bits
• Build: 26100
• Manufacturer: Microsoft Corporation

CPU

• Processor Name: Intel(R) Core(TM) i5-14400
• Cores: 10
• Logical Processors: 16
• Clock Speed: 2500 MHz

Memory

• Total Physical Memory: 16 GB
• Memory Type: 0

Ref Code

// ApplicationBuilder.cs
public static class ApplicationBuilder
{
    static readonly IconSource _Icon = IconSource.FromResource<MainView>("app_64_r.ico");
    static readonly string _AppTitle = "MVZ2SaveEditor";

    public static void Build()
    {
        RegisterPlatforms();
        CreateApp();
    }

    public static void HotBuild()
    {
        RegisterPlatforms();
        CreateHotApp();
    }

    private static void RegisterPlatforms()
    {
#if TARGET_WINDOWS
        Win32Platform.Register();
        Direct2DBackend.Register();

#elif TARGET_LINUX && !TARGET_ANDROID
        X11Platform.Register();
        MewVGX11Backend.Register();

#elif TARGET_OSX
        MacOSPlatform.Register();
        MewVGMacOSBackend.Register();
#endif
    }

    private static void CreateApp()
    {
        Application
            .Create()
            .BuildMainWindow(() =>
                new Window()
                    .Resizable(1280, 720)
                    .OnLoaded(() => { })
                    .OnClosed(() => { })
                    .Title(_AppTitle)
                    .Padding(8)
                    .Icon(_Icon)
                    .Content(new MainView(new MainVM()))
            )
            .Run();
    }

    private static void CreateHotApp()
    {
        var mv = new MainView(new MainVM());
        var window = new Window().OnBuild(x =>
            x.Resizable(1280, 720)
                .OnLoaded(() => { })
                .OnClosed(() => { })
                .Title(_AppTitle)
                .Padding(8)
                .Icon(_Icon)
                .Content(
                    new StackPanel()
                        .Spacing(8)
                        .Children(
                            mv,
                            new Button()
                                .Content("Reload")
                                .OnClick(() => MewUiHotReload.RequestReload([typeof(MainView)]))
                        )
                )
        );

        Application.Create().Run(window);
    }
}

// MVZ2SaveEditor.cs (The Program.cs with alias)
using MVZ2SaveEditor.Utils;
#if DEBUG

[assembly: System.Reflection.Metadata.MetadataUpdateHandler(
    typeof(Aprillz.MewUI.HotReload.MewUiMetadataUpdateHandler)
)]

#endif

namespace MVZ2SaveEditor;

class MVZ2SaveEditor
{
    [STAThread]
    static void Main()
    {
#if DEBUG
        ApplicationBuilder.HotBuild();
#endif
#if !DEBUG
        ApplicationBuilder.Build();
#endif
    }
}

[Sorrow-Scarlet]

When I changed MainView.cs 's layout, neither save source files nor click the reload button worked.

Also tried add content directly to window.Content() with this:

new TextBlock().Text($"Now: {DateTime.Now}")

Nothing happened.

[Sorrow-Scarlet]

Wait, is this hot reload for visual studio only? I'm using vs code.

[al6uiz]

This was caused by the filtering for modified types not working correctly during hot reload. As a temporary fix, I removed the filter.

Please check the v0.15.0 release.

[Sorrow-Scarlet]

This was caused by the filtering for modified types not working correctly during hot reload. As a temporary fix, I removed the filter.

Please check the v0.15.0 release.

I'm using the 0.15 MewUI, and in the counter sample, the hot reload is still not working, I'm a little bit confused. Any information needed?

[al6uiz]

I confirmed that this works correctly in Visual Studio 2026.

In VS Code, however, I was able to reproduce the issue: when Hot Reload changes are not applied, a warning is shown and the reload callback is not triggered.

At this point, this appears to be related to the VS Code Hot Reload behavior rather than the MewUI callback itself.

If I find a reliable workaround or solution, I will share it here.