ASP.NET Core Blazor project structure

This article describes the files and folders that make up a Blazor app generated from one of the Blazor framework's project templates.

Blazor WebAssembly

Blazor WebAssembly project template: blazorwasm

The Blazor WebAssembly template creates the initial files and directory structure for a Blazor WebAssembly app. The app is populated with demonstration code for a FetchData component that loads data from a static asset, weather.json, and user interaction with a Counter component.

  • Pages folder: Contains the routable components/pages (.razor) that make up the Blazor app. The route for each page is specified using the @page directive. The template includes the following components:

    • Counter component (Counter.razor): Implements the Counter page.
    • FetchData component (FetchData.razor): Implements the Fetch data page.
    • Index component (Index.razor): Implements the Home page.
  • Properties/launchSettings.json: Holds development environment configuration.

  • Shared folder: Contains the following shared components and stylesheets:

    • MainLayout component (MainLayout.razor): The app's layout component.
    • MainLayout.razor.css: Stylesheet for the app's main layout.
    • NavMenu component (NavMenu.razor): Implements sidebar navigation. Includes the NavLink component (NavLink), which renders navigation links to other Razor components. The NavLink component automatically indicates a selected state when its component is loaded, which helps the user understand which component is currently displayed.
    • NavMenu.razor.css: Stylesheet for the app's navigation menu.
    • SurveyPrompt component (SurveyPrompt.razor): Blazor survey component.
  • wwwroot: The Web Root folder for the app containing the app's public static assets, including appsettings.json and environmental app settings files for configuration settings. The index.html webpage is the root page of the app implemented as an HTML page:

    • When any page of the app is initially requested, this page is rendered and returned in the response.
    • The page specifies where the root App component is rendered. The component is rendered at the location of the div DOM element with an id of app (<div id="app">Loading...</div>).

Note

JavaScript (JS) files added to the wwwroot/index.html file should appear before the closing </body> tag. The order that custom JS code is loaded from JS files is important in some scenarios. For example, ensure that JS files with interop methods are included before Blazor framework JS files.

  • _Imports.razor: Includes common Razor directives to include in the app's components (.razor), such as @using directives for namespaces.

  • App.razor: The root component of the app that sets up client-side routing using the Router component. The Router component intercepts browser navigation and renders the page that matches the requested address.

  • Program.cs: The app's entry point that sets up the WebAssembly host:

    • The App component is the root component of the app. The App component is specified as the div DOM element with an id of app (<div id="app">Loading...</div> in wwwroot/index.html) to the root component collection (builder.RootComponents.Add<App>("#app")).
    • Services are added and configured (for example, builder.Services.AddSingleton<IMyDependency, MyDependency>()).

Blazor Server

Blazor Server project template: blazorserver

The Blazor Server template creates the initial files and directory structure for a Blazor Server app. The app is populated with demonstration code for a FetchData component that loads data from a registered service, WeatherForecastService, and user interaction with a Counter component.

  • Data folder: Contains the WeatherForecast class and implementation of the WeatherForecastService that provides example weather data to the app's FetchData component.

  • Pages folder: Contains the routable components/pages (.razor) that make up the Blazor app and the root Razor page of a Blazor Server app. The route for each page is specified using the @page directive. The template includes the following:

    • _Host.cshtml: The root page of the app implemented as a Razor Page:
      • When any page of the app is initially requested, this page is rendered and returned in the response.
      • The Host page specifies where the root App component (App.razor) is rendered.
    • _Layout.cshtml: The layout page for the _Host.cshtml root page of the app.
    • Counter component (Counter.razor): Implements the Counter page.
    • Error component (Error.razor): Rendered when an unhandled exception occurs in the app.
    • FetchData component (FetchData.razor): Implements the Fetch data page.
    • Index component (Index.razor): Implements the Home page.

Note

JavaScript (JS) files added to the Pages/_Layout.cshtml file should appear before the closing </body> tag. The order that custom JS code is loaded from JS files is important in some scenarios. For example, ensure that JS files with interop methods are included before Blazor framework JS files.

  • Properties/launchSettings.json: Holds development environment configuration.

  • Shared folder: Contains the following shared components and stylesheets:

    • MainLayout component (MainLayout.razor): The app's layout component.
    • MainLayout.razor.css: Stylesheet for the app's main layout.
    • NavMenu component (NavMenu.razor): Implements sidebar navigation. Includes the NavLink component (NavLink), which renders navigation links to other Razor components. The NavLink component automatically indicates a selected state when its component is loaded, which helps the user understand which component is currently displayed.
    • NavMenu.razor.css: Stylesheet for the app's navigation menu.
    • SurveyPrompt component (SurveyPrompt.razor): Blazor survey component.
  • wwwroot: The Web Root folder for the app containing the app's public static assets.

  • _Imports.razor: Includes common Razor directives to include in the app's components (.razor), such as @using directives for namespaces.

  • App.razor: The root component of the app that sets up client-side routing using the Router component. The Router component intercepts browser navigation and renders the page that matches the requested address.

  • appsettings.json and environmental app settings files: Provide configuration settings for the app.

  • Program.cs: The app's entry point that sets up the ASP.NET Core host and contains the app's startup logic, including service registrations and request processing pipeline configuration:

    • Specifies the app's dependency injection (DI) services. Services are added by calling AddServerSideBlazor, and the WeatherForecastService is added to the service container for use by the example FetchData component.
    • Configures the app's request handling pipeline:
      • MapBlazorHub is called to set up an endpoint for the real-time connection with the browser. The connection is created with SignalR, which is a framework for adding real-time web functionality to apps.
      • MapFallbackToPage("/_Host") is called to set up the root page of the app (Pages/_Host.cshtml) and enable navigation.

Additional resources

This article describes the files and folders that make up a Blazor app generated from one of the Blazor framework's project templates. For information on how to use tooling to create a Blazor app from a Blazor project template, see Tooling for ASP.NET Core Blazor. For information on Blazor's hosting models, Blazor WebAssembly and Blazor Server, see ASP.NET Core Blazor hosting models.

Blazor WebAssembly

Blazor WebAssembly project template: blazorwasm

The Blazor WebAssembly template creates the initial files and directory structure for a Blazor WebAssembly app. The app is populated with demonstration code for a FetchData component that loads data from a static asset, weather.json, and user interaction with a Counter component.

  • Pages folder: Contains the routable components/pages (.razor) that make up the Blazor app. The route for each page is specified using the @page directive. The template includes the following components:

    • Counter component (Counter.razor): Implements the Counter page.
    • FetchData component (FetchData.razor): Implements the Fetch data page.
    • Index component (Index.razor): Implements the Home page.
  • Properties/launchSettings.json: Holds development environment configuration.

  • Shared folder: Contains the following shared components and stylesheets:

    • MainLayout component (MainLayout.razor): The app's layout component.
    • MainLayout.razor.css: Stylesheet for the app's main layout.
    • NavMenu component (NavMenu.razor): Implements sidebar navigation. Includes the NavLink component (NavLink), which renders navigation links to other Razor components. The NavLink component automatically indicates a selected state when its component is loaded, which helps the user understand which component is currently displayed.
    • NavMenu.razor.css: Stylesheet for the app's navigation menu.
    • SurveyPrompt component (SurveyPrompt.razor): Blazor survey component.
  • wwwroot: The Web Root folder for the app containing the app's public static assets, including appsettings.json and environmental app settings files for configuration settings. The index.html webpage is the root page of the app implemented as an HTML page:

    • When any page of the app is initially requested, this page is rendered and returned in the response.
    • The page specifies where the root App component is rendered. The component is rendered at the location of the div DOM element with an id of app (<div id="app">Loading...</div>).

Note

JavaScript (JS) files added to the wwwroot/index.html file should appear before the closing </body> tag. The order that custom JS code is loaded from JS files is important in some scenarios. For example, ensure that JS files with interop methods are included before Blazor framework JS files.

  • _Imports.razor: Includes common Razor directives to include in the app's components (.razor), such as @using directives for namespaces.

  • App.razor: The root component of the app that sets up client-side routing using the Router component. The Router component intercepts browser navigation and renders the page that matches the requested address.

  • Program.cs: The app's entry point that sets up the WebAssembly host:

    • The App component is the root component of the app. The App component is specified as the div DOM element with an id of app (<div id="app">Loading...</div> in wwwroot/index.html) to the root component collection (builder.RootComponents.Add<App>("#app")).
    • Services are added and configured (for example, builder.Services.AddSingleton<IMyDependency, MyDependency>()).

Blazor Server

Blazor Server project template: blazorserver

The Blazor Server template creates the initial files and directory structure for a Blazor Server app. The app is populated with demonstration code for a FetchData component that loads data from a registered service, WeatherForecastService, and user interaction with a Counter component.

  • Data folder: Contains the WeatherForecast class and implementation of the WeatherForecastService that provides example weather data to the app's FetchData component.

  • Pages folder: Contains the routable components/pages (.razor) that make up the Blazor app and the root Razor page of a Blazor Server app. The route for each page is specified using the @page directive. The template includes the following:

    • _Host.cshtml: The root page of the app implemented as a Razor Page:
      • When any page of the app is initially requested, this page is rendered and returned in the response.
      • The Host page specifies where the root App component (App.razor) is rendered.
    • Counter component (Counter.razor): Implements the Counter page.
    • Error component (Error.razor): Rendered when an unhandled exception occurs in the app.
    • FetchData component (FetchData.razor): Implements the Fetch data page.
    • Index component (Index.razor): Implements the Home page.

Note

JavaScript (JS) files added to the Pages/_Host.cshtml file should appear before the closing </body> tag. The order that custom JS code is loaded from JS files is important in some scenarios. For example, ensure that JS files with interop methods are included before Blazor framework JS files.

  • Properties/launchSettings.json: Holds development environment configuration.

  • Shared folder: Contains the following shared components and stylesheets:

    • MainLayout component (MainLayout.razor): The app's layout component.
    • MainLayout.razor.css: Stylesheet for the app's main layout.
    • NavMenu component (NavMenu.razor): Implements sidebar navigation. Includes the NavLink component (NavLink), which renders navigation links to other Razor components. The NavLink component automatically indicates a selected state when its component is loaded, which helps the user understand which component is currently displayed.
    • NavMenu.razor.css: Stylesheet for the app's navigation menu.
    • SurveyPrompt component (SurveyPrompt.razor): Blazor survey component.
  • wwwroot: The Web Root folder for the app containing the app's public static assets.

  • _Imports.razor: Includes common Razor directives to include in the app's components (.razor), such as @using directives for namespaces.

  • App.razor: The root component of the app that sets up client-side routing using the Router component. The Router component intercepts browser navigation and renders the page that matches the requested address.

  • appsettings.json and environmental app settings files: Provide configuration settings for the app.

  • Program.cs: The app's entry point that sets up the ASP.NET Core host.

  • Startup.cs: Contains the app's startup logic. The Startup class defines two methods:

    • ConfigureServices: Configures the app's dependency injection (DI) services. Services are added by calling AddServerSideBlazor, and the WeatherForecastService is added to the service container for use by the example FetchData component.
    • Configure: Configures the app's request handling pipeline:
      • MapBlazorHub is called to set up an endpoint for the real-time connection with the browser. The connection is created with SignalR, which is a framework for adding real-time web functionality to apps.
      • MapFallbackToPage("/_Host") is called to set up the root page of the app (Pages/_Host.cshtml) and enable navigation.

Additional resources

This article describes the files and folders that make up a Blazor app generated from one of the Blazor framework's project templates. For information on how to use tooling to create a Blazor app from a Blazor project template, see Tooling for ASP.NET Core Blazor. For information on Blazor's hosting models, Blazor WebAssembly and Blazor Server, see ASP.NET Core Blazor hosting models.

Blazor WebAssembly

Blazor WebAssembly project template: blazorwasm

The Blazor WebAssembly template creates the initial files and directory structure for a Blazor WebAssembly app. The app is populated with demonstration code for a FetchData component that loads data from a static asset, weather.json, and user interaction with a Counter component.

  • Pages folder: Contains the routable components/pages (.razor) that make up the Blazor app. The route for each page is specified using the @page directive. The template includes the following components:

    • Counter component (Counter.razor): Implements the Counter page.
    • FetchData component (FetchData.razor): Implements the Fetch data page.
    • Index component (Index.razor): Implements the Home page.
  • Properties/launchSettings.json: Holds development environment configuration.

  • Shared folder: Contains the following shared components:

    • MainLayout component (MainLayout.razor): The app's layout component.
    • NavMenu component (NavMenu.razor): Implements sidebar navigation. Includes the NavLink component (NavLink), which renders navigation links to other Razor components. The NavLink component automatically indicates a selected state when its component is loaded, which helps the user understand which component is currently displayed.
    • SurveyPrompt component (SurveyPrompt.razor): Blazor survey component.
  • wwwroot: The Web Root folder for the app containing the app's public static assets, including appsettings.json and environmental app settings files for configuration settings. The index.html webpage is the root page of the app implemented as an HTML page:

    • When any page of the app is initially requested, this page is rendered and returned in the response.
    • The page specifies where the root App component is rendered. The component is rendered at the location of the app DOM element (<app>Loading...</app>).

Note

JavaScript (JS) files added to the wwwroot/index.html file should appear before the closing </body> tag. The order that custom JS code is loaded from JS files is important in some scenarios. For example, ensure that JS files with interop methods are included before Blazor framework JS files.

  • _Imports.razor: Includes common Razor directives to include in the app's components (.razor), such as @using directives for namespaces.

  • App.razor: The root component of the app that sets up client-side routing using the Router component. The Router component intercepts browser navigation and renders the page that matches the requested address.

  • Program.cs: The app's entry point that sets up the WebAssembly host:

    • The App component is the root component of the app. The App component is specified as the app DOM element (<app>Loading...</app> in wwwroot/index.html) to the root component collection (builder.RootComponents.Add<App>("app")).
    • Services are added and configured (for example, builder.Services.AddSingleton<IMyDependency, MyDependency>()).

Blazor Server

Blazor Server project template: blazorserver

The Blazor Server template creates the initial files and directory structure for a Blazor Server app. The app is populated with demonstration code for a FetchData component that loads data from a registered service, WeatherForecastService, and user interaction with a Counter component.

  • Data folder: Contains the WeatherForecast class and implementation of the WeatherForecastService that provides example weather data to the app's FetchData component.

  • Pages folder: Contains the routable components/pages (.razor) that make up the Blazor app and the root Razor page of a Blazor Server app. The route for each page is specified using the @page directive. The template includes the following:

    • _Host.cshtml: The root page of the app implemented as a Razor Page:
      • When any page of the app is initially requested, this page is rendered and returned in the response.
      • The Host page specifies where the root App component (App.razor) is rendered.
    • Counter component (Counter.razor): Implements the Counter page.
    • Error component (Error.razor): Rendered when an unhandled exception occurs in the app.
    • FetchData component (FetchData.razor): Implements the Fetch data page.
    • Index component (Index.razor): Implements the Home page.

Note

JavaScript (JS) files added to the Pages/_Host.cshtml file should appear before the closing </body> tag. The order that custom JS code is loaded from JS files is important in some scenarios. For example, ensure that JS files with interop methods are included before Blazor framework JS files.

  • Properties/launchSettings.json: Holds development environment configuration.

  • Shared folder: Contains the following shared components:

    • MainLayout component (MainLayout.razor): The app's layout component.
    • NavMenu component (NavMenu.razor): Implements sidebar navigation. Includes the NavLink component (NavLink), which renders navigation links to other Razor components. The NavLink component automatically indicates a selected state when its component is loaded, which helps the user understand which component is currently displayed.
    • SurveyPrompt component (SurveyPrompt.razor): Blazor survey component.
  • wwwroot: The Web Root folder for the app containing the app's public static assets.

  • _Imports.razor: Includes common Razor directives to include in the app's components (.razor), such as @using directives for namespaces.

  • App.razor: The root component of the app that sets up client-side routing using the Router component. The Router component intercepts browser navigation and renders the page that matches the requested address.

  • appsettings.json and environmental app settings files: Provide configuration settings for the app.

  • Program.cs: The app's entry point that sets up the ASP.NET Core host.

  • Startup.cs: Contains the app's startup logic. The Startup class defines two methods:

    • ConfigureServices: Configures the app's dependency injection (DI) services. Services are added by calling AddServerSideBlazor, and the WeatherForecastService is added to the service container for use by the example FetchData component.
    • Configure: Configures the app's request handling pipeline:
      • MapBlazorHub is called to set up an endpoint for the real-time connection with the browser. The connection is created with SignalR, which is a framework for adding real-time web functionality to apps.
      • MapFallbackToPage("/_Host") is called to set up the root page of the app (Pages/_Host.cshtml) and enable navigation.

Additional resources