fluentui-blazor

name fluentui-blazor description Guide for using the Microsoft Fluent UI Blazor component library (Microsoft.FluentUI.AspNetCore.Components NuGet package) in Blazor applications. Use this when the user is building a Blazor app with Fluent UI components, setting up the library, using FluentUI components like FluentButton, FluentDataGrid, FluentDialog, FluentToast, FluentNavMenu, FluentTextField, FluentSelect, FluentAutocomplete, FluentDesignTheme, or any component prefixed with "Fluent". Also use when troubleshooting missing providers, JS interop issues, or theming. 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. 5. List component binding model FluentSelect<TOption> , FluentCombobox<TOption> , FluentListbox<TOption> , and FluentAutocomplete<TOption> do NOT work like <InputSelect> . They use: Items — the data source ( IEnumerable<TOption> ) OptionText — Func<TOption, string?> to extract display text OptionValue — Func<TOption, string?> to extract the value string SelectedOption / SelectedOptionChanged — for single selection binding SelectedOptions / SelectedOptionsChanged — for multi-selection binding <FluentSelect Items="@countries" OptionText="@(c => c.Name)" OptionValue="@(c => c.Code)" @bind-SelectedOption="@selectedCountry" Label="Country" /> NOT like this (wrong pattern): @* WRONG — do not use InputSelect pattern *@ <FluentSelect @bind-Value="@selectedValue"> <option value="1">One</option> </FluentSelect> 6. FluentAutocomplete specifics Use ValueText (NOT Value — it's obsolete) for the search input text OnOptionsSearch is the required callback to filter options Default is Multiple="true" <FluentAutocomplete TOption="Person" OnOptionsSearch="@OnSearch" OptionText="@(p => p.FullName)" @bind-SelectedOptions="@selectedPeople" Label="Search people" /> @code { private void OnSearch(OptionsSearchEventArgs<Person> args) { args.Items = allPeople.Where(p => p.FullName.Contains(args.Text, StringComparison.OrdinalIgnoreCase)); } } 7. Dialog service pattern Do NOT toggle visibility of <FluentDialog> tags. The service pattern is: Create a content component implementing IDialogContentComponent<TData> : public partial class EditPersonDialog : IDialogContentComponent < Person > { [ Parameter ] public Person Content { get ; set ; } = default !; [ CascadingParameter ] public FluentDialog Dialog { get ; set ; } = default !; private async Task SaveAsync () { await Dialog.CloseAsync(Content); } private async Task CancelAsync () { await Dialog.CancelAsync(); } } Show the dialog via IDialogService : [ Inject ] private IDialogService DialogService { get ; set ; } = default !; private async Task ShowEditDialog () { var dialog = await DialogService.ShowDialogAsync<EditPersonDialog, Person>( person, new DialogParameters { Title = "Edit Person" , PrimaryAction = "Save" , SecondaryAction = "Cancel" , Width = "500px" , PreventDismissOnOverlayClick = true , }); var result = await dialog.Result; if (!result.Cancelled) { var updatedPerson = result.Data as Person; } } For convenience dialogs: await DialogService.ShowConfirmationAsync( "Are you sure?" , "Yes" , "No" ); await DialogService.ShowSuccessAsync( "Done!" ); await DialogService.ShowErrorAsync( "Something went wrong." ); 8. Toast notifications [ Inject ] private IToastService ToastService { get ; set ; } = default !; ToastService.ShowSuccess( "Item saved successfully" ); ToastService.ShowError( "Failed to save" ); ToastService.ShowWarning( "Check your input" ); ToastService.ShowInfo( "New update available" ); FluentToastProvider parameters: Position (default TopRight ), Timeout (default 7000ms), MaxToastCount (default 4). 9. Design tokens and themes work only after render Design tokens rely on JS interop. Never set them in OnInitialized — use OnAfterRenderAsync . <FluentDesignTheme Mode="DesignThemeModes.System" OfficeColor="OfficeColor.Teams" StorageName="mytheme" /> 10. FluentEditForm vs EditForm FluentEditForm is only needed inside FluentWizard steps (per-step validation). For regular forms, use standard EditForm with Fluent form components: <EditForm Model="@model" OnValidSubmit="HandleSubmit"> <DataAnnotationsValidator /> <FluentTextField @bind-Value="@model.Name" Label="Name" Required /> <FluentSelect Items="@options" OptionText="@(o => o.Label)" @bind-SelectedOption="@model.Category" Label="Category" /> <FluentValidationSummary /> <FluentButton Type="ButtonType.Submit" Appearance="Appearance.Accent">Save</FluentButton> </EditForm> Use FluentValidationMessage and FluentValidationSummary instead of standard Blazor validation components for Fluent styling. Reference files For detailed guidance on specific topics, see: Setup and configuration Layout and navigation Data grid Theming