Getting Started with Blazor ListBox Component

29 Jun 202211 minutes to read

This section briefly explains about how to include Blazor ListBox component in Blazor Server App and Blazor WebAssembly App using Visual Studio.

To get start quickly with ListBox Component using Blazor, check on this video:

Prerequisites

Create a new Blazor App in Visual Studio

You can create Blazor Server App or Blazor WebAssembly App using Visual Studio in one of the following ways,

Install Syncfusion Blazor DropDowns NuGet in the App

Syncfusion Blazor components are available in nuget.org. To use Syncfusion Blazor components in the application, add reference to the corresponding NuGet. Refer to NuGet packages topic for available NuGet packages list with component details and Benefits of using individual NuGet packages.

To add Blazor ListBox component in the app, open the NuGet package manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), search for Syncfusion.Blazor.DropDowns and then install it.

Register Syncfusion Blazor Service

Open ~/_Imports.razor file and import the Syncfusion.Blazor namespace.

@using Syncfusion.Blazor

Now, register the Syncfusion Blazor Service in the Blazor Server App or Blazor WebAssembly App. Here, Syncfusion Blazor Service is registered by setting IgnoreScriptIsolation property as true to load the scripts externally in the next steps.

From 2022 Vol1 (20.1) version - The default value of IgnoreScriptIsolation is changed as true, so, you don’t have to set IgnoreScriptIsolation property explicitly to refer scripts externally.

Blazor Server App

  • For .NET 6 app, open the ~/Program.cs file and register the Syncfusion Blazor Service.

  • For .NET 5 and .NET 3.X app, open the ~/Startup.cs file and register the Syncfusion Blazor Service.

using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web;
using Syncfusion.Blazor;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddSyncfusionBlazor(options => { options.IgnoreScriptIsolation = true; });

var app = builder.Build();
....
using Syncfusion.Blazor;

namespace BlazorApplication
{
    public class Startup
    {
        ...
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddRazorPages();
            services.AddServerSideBlazor();
            services.AddSyncfusionBlazor(options => { options.IgnoreScriptIsolation = true; });
        }
        ...
    }
}

Blazor WebAssembly App

Open ~/Program.cs file and register the Syncfusion Blazor Service in the client web app.

using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
using Syncfusion.Blazor;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.RootComponents.Add<HeadOutlet>("head::after");

builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });

builder.Services.AddSyncfusionBlazor(options => { options.IgnoreScriptIsolation = true; });
await builder.Build().RunAsync();
....
using Syncfusion.Blazor;

namespace WebApplication1
{
    public class Program
    {
        public static async Task Main(string[] args)
        {
            ....
            builder.Services.AddSyncfusionBlazor(options => { options.IgnoreScriptIsolation = true; });
            await builder.Build().RunAsync();
        }
    }
}

Add Style Sheet

Checkout the Blazor Themes topic to learn different ways (Static Web Assets, CDN and CRG) to refer themes in Blazor application, and to have the expected appearance for Syncfusion Blazor components. Here, the theme is referred using Static Web Assets. Refer to Enable static web assets usage topic to use static assets in your project.

To add theme to the app, open the NuGet package manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), search for Syncfusion.Blazor.Themes and then install it. Then, the theme style sheet from NuGet can be referred as follows,

If you are using Syncfusion.Blazor single NuGet, you don’t have to refer Syncfusion.Blazor.Themes NuGet. Since style sheets already inside the assets of Syncfusion.Blazor NuGet.

Blazor Server App

  • For .NET 6 app, add the Syncfusion bootstrap5 theme in the <head> of the ~/Pages/_Layout.cshtml file.

  • For .NET 5 and .NET 3.X app, add the Syncfusion bootstrap5 theme in the <head> of the ~/Pages/_Host.cshtml file.

<head>
    ...
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
    <!--Refer theme style sheet as below if you are using Syncfusion.Blazor Single NuGet-->
    <!--<link href="_content/Syncfusion.Blazor/styles/bootstrap5.css" rel="stylesheet" />-->
</head>
<head>
    ...
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
    <!--Refer theme style sheet as below if you are using Syncfusion.Blazor Single NuGet-->
    <!--<link href="_content/Syncfusion.Blazor/styles/bootstrap5.css" rel="stylesheet" />-->
</head>

Blazor WebAssembly App

For Blazor WebAssembly App, refer the theme style sheet from NuGet in the <head> of wwwroot/index.html file in the client web app.

<head>
    ...
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
    <!--Refer theme style sheet as below if you are using Syncfusion.Blazor Single NuGet-->
    <!--<link href="_content/Syncfusion.Blazor/styles/bootstrap5.css" rel="stylesheet" />-->
</head>

Add Script Reference

Checkout Adding Script Reference topic to learn different ways to add script reference in Blazor Application. In this getting started walk-through, the required scripts are referred using Static Web Assets externally inside the <head> as follows. Refer to Enable static web assets usage topic to use static assets in your project.

Blazor Server App

  • For .NET 6 app, refer script in the <head> of the ~/Pages/_Layout.cshtml file.

  • For .NET 5 and .NET 3.X app, refer script in the <head> of the ~/Pages/_Host.cshtml file.

<head>
    ....
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
    <script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>
    <!--Use below script reference if you are using Syncfusion.Blazor Single NuGet-->
    <!--<script  src="_content/Syncfusion.Blazor/scripts/syncfusion-blazor.min.js"  type="text/javascript"></script>-->
</head>
<head>
    ....
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
    <script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>
    <!--Use below script reference if you are using Syncfusion.Blazor Single NuGet-->
    <!--<script  src="_content/Syncfusion.Blazor/scripts/syncfusion-blazor.min.js"  type="text/javascript"></script>-->
</head>

Blazor WebAssembly App

For Blazor WebAssembly App, refer script in the <head> of the ~/index.html file.

<head>
    ....
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
    <script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>
    <!--Use below script reference if you are using Syncfusion.Blazor Single NuGet-->
    <!--<script  src="_content/Syncfusion.Blazor/scripts/syncfusion-blazor.min.js"  type="text/javascript"></script>-->
</head>

Syncfusion recommends to reference scripts using Static Web Assets, CDN and CRG by disabling JavaScript isolation for better loading performance of the Blazor application.

Add Blazor ListBox component

  • Open ~/_Imports.razor file or any other page under the ~/Pages folder where the component is to be added and import the Syncfusion.Blazor.DropDowns namespace.
@using Syncfusion.Blazor
@using Syncfusion.Blazor.DropDowns
  • Now, add the Syncfusion ListBox component in razor file. Here, the ListBox component is added in the ~/Pages/Index.razor file under the ~/Pages folder.
<SfListBox TValue="string[]"></SfListBox>

Binding data source

After initializing, populate the ListBox with data using the DataSource property. Here, an array of object values is passed to the ListBox component.

<SfListBox TValue="string[]" DataSource="@Vehicles" TItem="VehicleData">
    <ListBoxFieldSettings Text="Text" Value="Id" />
</SfListBox>
@code {
    public List<VehicleData> Vehicles = new List<VehicleData> {
        new VehicleData { Text = "Hennessey Venom", Id = "Vehicle-01" },
        new VehicleData { Text = "Bugatti Chiron", Id = "Vehicle-02" },
        new VehicleData { Text = "Bugatti Veyron Super Sport", Id = "Vehicle-03" },
        new VehicleData { Text = "SSC Ultimate Aero", Id = "Vehicle-04" },
        new VehicleData { Text = "Koenigsegg CCR", Id = "Vehicle-05" },
        new VehicleData { Text = "McLaren F1", Id = "Vehicle-06" },
        new VehicleData { Text = "Aston Martin One- 77", Id = "Vehicle-07" },
        new VehicleData { Text = "Jaguar XJ220", Id = "Vehicle-08" }
    };

    public class VehicleData {
      public string Text  { get; set; }
      public string Id  { get; set; }
    }
}

TValue is the type of value in the datasource to resolve type inference. It is generic type and can be given as string[], int[].

  • Press Ctrl+F5 (Windows) or +F5 (macOS) to run the application. Then, the Syncfusion Blazor ListBox component will be rendered in the default web browser.

Blazor ListBox Component

View Sample in GitHub.

See Also