When compiling with a multi-target framework, Avalonia's window UI does not preview properly

[pkq520]

Describe the bug

I use the class library of frmework4.8 with net8.0 multi-target framework, where frmework4.8's UI designer works fine, but Avalonia's UI can't be previewed, but the project compiles normally.

To Reproduce

类库框架的项目设置为 VS上的错误像这样

Expected behavior

It will be the same as what I see in my photo, the UI can't be previewed, but it compiles fine

Avalonia version

11.1.0

OS

Windows

Additional context

No response

[mrlacey]

Use of the Previewer requires a desktop build of the app. Try also adding a reference to the Avalonia.Desktop package as part of the net8.0 build.

    <PackageReference Include="Avalonia.Desktop" Version="11.3.4" />