fluentui-blazor

Fluent UI Blazor — Consumer Usage Guide

This skill teaches how to correctly use the Microsoft.FluentUI.AspNetCore.Components (version 4) NuGet package in Blazor applications.

Critical Rules

1. No manual <script> or <link> tags needed

The library auto-loads all CSS and JS via Blazor's static web assets and JS initializers. Never tell users to add <script> or <link> tags for the core library.

2. Providers are mandatory for service-based components

These provider components MUST be added to the root layout (e.g. MainLayout.razor) for their corresponding services to work. Without them, service calls fail silently (no error, no UI).

<FluentToastProvider />
<FluentDialogProvider />
<FluentMessageBarProvider />
<FluentTooltipProvider />
<FluentKeyCodeProvider />

3. Service registration in Program.cs

builder.Services.AddFluentUIComponents();

// Or with configuration:
builder.Services.AddFluentUIComponents(options =>
{
    options.UseTooltipServiceProvider = true;  // default: true
    options.ServiceLifetime = ServiceLifetime.Scoped; // default
});

ServiceLifetime rules:

• ServiceLifetime.Scoped — for Blazor Server / Interactive (default)
• ServiceLifetime.Singleton — for Blazor WebAssembly standalone
• ServiceLifetime.Transient — throws NotSupportedException

4. Icons require a separate NuGet package

dotnet add package Microsoft.FluentUI.AspNetCore.Components.Icons

Usage with a @using alias:

@using Icons = Microsoft.FluentUI.AspNetCore.Components.Icons

<FluentIcon Value="@(Icons.Regular.Size24.Save)" />
<FluentIcon Value="@(Icons.Filled.Size20.Delete)" Color="@Color.Error" />

Pattern: Icons.[Variant].[Size].[Name]

• Variants: Regular, Filled
• Sizes: Size12, Size16, Size20, Size24, Size28, Size32, Size48

Custom image: Icon.FromImageUrl("/path/to/image.png")

Never use string-based icon names — icons are strongly-typed classes.