CSS isolation in blazor-server components

Question

with the new .NET 5 preview CSS isolation comes in blazor. Does anybody know, is it possible to use the CSS isolation in blazor server?

I have play a lot around, but in my blazor server app CSS isolation doesn't work. Or is this feature only available in blazor WebAssembly?

so I tried it:

• create a new blazor component, e.g. test.razor
• create component CSS file with name test.razor.css and write the CSS code in this file
• now start the blazor-server app, but no static CSS file will added and the CSS classes doesn't found.

TargetFramework is "net5.0". installed dotnet version is "5.0.100-rc.2.20479.15".

greetings Daniel

Mog

The template uses it by default in Server-side. For example MainLayout.razor and MainLayout.razor.css – Bloom

i tried it exactly so, but it doesn't work – Mog

Answer 1

ok i found the issue. In my "_Host.cshtml" file was the link to the "project.styles.css" missing:

<link href="ProjectName.styles.css" rel="stylesheet" />

with this everything works fine.

Mog

Thank you for the hint. Also keep in mind that the {ProjectName} has to match Solution > Project > Properties > Package > Product. This may be different to the Project namespace. – Theall

This also worked for me, but is it anywhere in the documentation that this needs to be added for CSS isolation to work? – Ricercar

yes have a look at learn.microsoft.com/en-us/aspnet/core/blazor/components/… – Mog

Answer 2

If you are using .NET 6.0 blazor server side, paste the following line:

<link href="ProjectName.styles.css" rel="stylesheet" />

On the Pages > _Layout.cshtml file and it will work as expected.

Defensive