Getting Started with Blazor ComboBox Component
23 Dec 20258 minutes to read
This section explains how to include the Blazor ComboBox component in a Blazor WebAssembly app using Visual Studio, Visual Studio Code, and the .NET CLI.
To get started quickly with the Blazor ComboBox component, refer to this GitHub sample.
Prerequisites
Create a new Blazor App in Visual Studio
Create a Blazor WebAssembly App using Visual Studio via Microsoft Templates or the Syncfusion® Blazor Extension. For detailed instructions, refer to the Blazor WASM App Getting Started documentation.
Install Syncfusion® Blazor DropDowns and Themes NuGet in the App
To add the Blazor ComboBox component to the app, open the NuGet Package Manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), then search and install Syncfusion.Blazor.DropDowns and Syncfusion.Blazor.Themes. Alternatively, run the following commands in the Package Manager Console to achieve the same.
Install-Package Syncfusion.Blazor.DropDowns -Version 32.1.19
Install-Package Syncfusion.Blazor.Themes -Version 32.1.19NOTE
Syncfusion® Blazor components are available in nuget.org. Refer to the NuGet packages topic for the available NuGet packages list with component details.
Prerequisites
Create a new Blazor App in Visual Studio Code
Create a Blazor WebAssembly App using Visual Studio Code via Microsoft Templates or the Syncfusion® Blazor Extension. For detailed instructions, refer to the Blazor WASM App Getting Started documentation.
Alternatively, create a WebAssembly application by using the following command in the integrated terminal(Ctrl+`).
dotnet new blazorwasm -o BlazorApp
cd BlazorAppInstall Syncfusion® Blazor DropDowns and Themes NuGet in the App
- Press Ctrl+` to open the integrated terminal in Visual Studio Code.
- Ensure in the project root directory where the
.csprojfile is located. - Run the following commands to install the Syncfusion.Blazor.DropDowns and Syncfusion.Blazor.Themes NuGet packages and ensure all dependencies are installed.
dotnet add package Syncfusion.Blazor.DropDowns -v 32.1.19
dotnet add package Syncfusion.Blazor.Themes -v 32.1.19
dotnet restoreNOTE
Syncfusion® Blazor components are available in nuget.org. Refer to the NuGet packages topic for the available NuGet packages list with component details.
Prerequisites
Install the latest version of .NET SDK. If the .NET SDK is already installed, determine the installed version by running the following command in a command prompt (Windows), terminal (macOS), or command shell (Linux).
dotnet --versionCreate a Blazor WebAssembly App using .NET CLI
Run the following command to create a new Blazor WebAssembly App in a command prompt (Windows) or terminal (macOS) or command shell (Linux). For detailed instructions, refer to this Blazor WASM App Getting Started documentation.
dotnet new blazorwasm -o BlazorApp
cd BlazorAppInstall Syncfusion® Blazor DropDowns and Themes NuGet in the App
To add the Blazor ComboBox component to the application, run the following commands in a command prompt (Windows), command shell (Linux), or terminal (macOS) to install the Syncfusion.Blazor.DropDowns and Syncfusion.Blazor.Themes NuGet packages. See Install and manage packages using the dotnet CLI for more details.
dotnet add package Syncfusion.Blazor.DropDowns -Version 32.1.19
dotnet add package Syncfusion.Blazor.Themes -Version 32.1.19
dotnet restoreNOTE
Syncfusion® Blazor components are available in nuget.org. Refer to the NuGet packages topic for the available NuGet packages list with component details.
Add Import Namespaces
Open the ~/_Imports.razor file and import the Syncfusion.Blazor and Syncfusion.Blazor.DropDowns namespaces.
@using Syncfusion.Blazor
@using Syncfusion.Blazor.DropDownsRegister Syncfusion® Blazor Service
Register the Syncfusion® Blazor Service in the ~/Program.cs file of the Blazor WebAssembly 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();
await builder.Build().RunAsync();
....Add stylesheet and script resources
The theme stylesheet and script can be accessed from NuGet through Static Web Assets. Include the stylesheet and script references within the <head> section 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>
</head>NOTE
See the Blazor Themes topic for different methods (Static Web Assets, CDN, and CRG) to reference themes. See Adding Script Reference for guidance on adding script references in a Blazor application.
Add Blazor ComboBox component
Add the Syncfusion® Blazor ComboBox component to the ~/Pages/Index.razor file.
<SfComboBox TValue="string" TItem="string" Placeholder="Select a game"></SfComboBox>- Press Ctrl+F5 (Windows) or ⌘+F5 (macOS) to launch the application. This will render the Syncfusion® Blazor ComboBox component in the default web browser.
Binding data source
After initialization, populate the ComboBox with data using the DataSource property. In the following example, a list of objects (with ID and Text fields) is bound to the ComboBox.
<SfComboBox TValue="string" TItem="Games" Placeholder="Select a game" DataSource="@LocalData">
<ComboBoxFieldSettings Value="ID" Text="Text"></ComboBoxFieldSettings>
</SfComboBox>
@code {
public class Games
{
public string ID { get; set; }
public string Text { get; set; }
}
List<Games> LocalData = new List<Games> {
new Games() { ID= "Game1", Text= "American Football" },
new Games() { ID= "Game2", Text= "Badminton" },
new Games() { ID= "Game3", Text= "Basketball" },
new Games() { ID= "Game4", Text= "Cricket" },
new Games() { ID= "Game5", Text= "Football" },
new Games() { ID= "Game6", Text= "Golf" },
new Games() { ID= "Game7", Text= "Hockey" },
new Games() { ID= "Game8", Text= "Rugby"},
new Games() { ID= "Game9", Text= "Snooker" },
new Games() { ID= "Game10", Text= "Tennis"},
};
}
Custom values
The ComboBox supports custom values that are not present in the predefined list. This behavior is enabled by the AllowCustom property. In this mode, the typed text is treated as both the display text and the value, and the custom value is posted with the form on submit.
<SfComboBox TValue="string" TItem="Games" AllowCustom=true Placeholder="Select a game" DataSource="@LocalData">
<ComboBoxFieldSettings Value="ID" Text="Text"></ComboBoxFieldSettings>
</SfComboBox>
Configure the popup list
By default, the popup list width automatically adjusts to the ComboBox input width, and the popup height is 350px. The height and width of the popup list can be customized using the PopupHeight and PopupWidth properties.
<SfComboBox TValue="string" TItem="Games"PopupHeight="350px" PopupWidth="350px" Placeholder="Select a game" DataSource="@LocalData">
<ComboBoxFieldSettings Value="ID" Text="Text"></ComboBoxFieldSettings>
</SfComboBox>