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Getting Started with Blazor ComboBox Component in Blazor Web App

14 Apr 20268 minutes to read

This section briefly explains about how to include Syncfusion® Blazor ComboBox component in your Blazor Web App using Visual Studio, Visual Studio Code, and the .NET CLI.

Prerequisites

Create a new Blazor Web App in Visual Studio

Create a Blazor Web App using Visual Studio via Microsoft Templates or the Syncfusion® Blazor Extension. For detailed instructions, refer to the Blazor Web App Getting Started documentation.

Prerequisites

Create a new Blazor Web App in Visual Studio Code

Create a Blazor Web App using Visual Studio Code via Microsoft Templates or the Syncfusion® Blazor Extension. For detailed instructions, refer to the Blazor Web App Getting Started documentation.

For example, in a Blazor Web App with the Auto interactive render mode, use the following commands in the integrated terminal (Ctrl+`).

dotnet new blazor -o BlazorWebApp -int Auto
cd BlazorWebApp
cd BlazorWebApp.Client

Prerequisites

Install the latest version of .NET SDK. If you previously installed the SDK, you can determine the installed version by executing the following command in a command prompt (Windows) or terminal (macOS) or command shell (Linux).

dotnet --version

Create a Blazor Web App using .NET CLI

Run the following command to create a new Blazor Web App in a command prompt (Windows) or terminal (macOS) or command shell (Linux). For detailed instructions, refer to the Blazor Web App Getting Started documentation.

For example, in a Blazor Web App with the Auto interactive render mode, use the following commands:

dotnet new blazor -o BlazorWebApp -int Auto
cd BlazorWebApp
cd BlazorWebApp.Client

This command creates a new Blazor Web App and places it in a new directory called BlazorWebApp inside your current location. See the Create a Blazor App and dotnet new CLI command topics for more details.

NOTE

Configure the appropriate Interactive render mode and Interactivity location while creating a Blazor Web App. For detailed information, refer to the interactive render mode documentation.

Install Syncfusion® Blazor packages

Install Syncfusion.Blazor.DropDowns and Syncfusion.Blazor.Themes NuGet packages in your project using the NuGet Package Manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), or the integrated terminal in Visual Studio Code (dotnet add package), or the .NET CLI.

Alternatively, run the following commands in the Package Manager Console to achieve the same.

Install-Package Syncfusion.Blazor.DropDowns -Version 33.1.44
Install-Package Syncfusion.Blazor.Themes -Version 33.1.44

If using the WebAssembly or Auto render modes in the Blazor Web App, install these packages in the client project.

NOTE

All Syncfusion Blazor packages are available on nuget.org. See the NuGet packages topic for details.

Add import namespaces

After the packages are installed, open the ~/_Imports.razor file in the client project and import the Syncfusion.Blazor and Syncfusion.Blazor.DropDowns namespaces.

@using Syncfusion.Blazor
@using Syncfusion.Blazor.DropDowns

Register Syncfusion® Blazor service

Register the Syncfusion® Blazor service in the Program.cs file of your Blazor Web App.

....
using Syncfusion.Blazor;
....
builder.Services.AddSyncfusionBlazor();
....

NOTE

If the Interactive Render Mode is set to WebAssembly or Auto, register the Syncfusion® Blazor service in Program.cs files of both the server and client projects in your Blazor Web App.

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 in the ~/Components/App.razor file.

<link href="_content/Syncfusion.Blazor.Themes/fluent2.css" rel="stylesheet" />
....
<script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>

NOTE

Check out the Blazor Themes topic to discover various methods (Static Web Assets, CDN, and CRG) for referencing themes in your Blazor application. Also, check out the Adding Script Reference topic to learn different approaches for adding script references in your Blazor application.

Add Syncfusion® Blazor ComboBox component

Add the Syncfusion® Blazor ComboBox component in the ~/Components/Pages/*.razor file. If the interactivity location is set to Per page/component in the Web App, define a render mode at the top of the ~Pages/*.razor file. (For example, InteractiveServer, InteractiveWebAssembly or InteractiveAuto).

NOTE

If the Interactivity Location is set to Global with Auto or WebAssembly, the render mode is automatically configured in the App.razor file by default.

@* desired render mode define here *@
@rendermode InteractiveAuto
<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.
Blazor ComboBox Component

Binding data source

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

<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"},
  };
}
Blazor ComboBox with Data Binding

Custom values

The ComboBox allows users to input custom values that are not present in the predefined list. This support is enabled by the AllowCustom property. In this case, the text and value are treated the same, 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>
Blazor ComboBox with Custom Values

Configure the popup list

By default, the popup list width automatically matches the ComboBox input width, and the popup height is 350px. The height and width can be customized using the PopupHeight and PopupWidth properties, respectively.

<SfComboBox TValue="string" TItem="Games"PopupHeight="350px" PopupWidth="350px" Placeholder="Select a game" DataSource="@LocalData">
    <ComboBoxFieldSettings Value="ID" Text="Text"></ComboBoxFieldSettings>
</SfComboBox>
Customizing Popup Height and Width in Blazor ComboBox

NOTE

View Sample in GitHub.

See also

  1. Getting Started with Syncfusion® Blazor for client-side in .NET Core CLI
  2. Getting Started with Syncfusion® Blazor for client-side in Visual Studio
  3. Getting Started with Syncfusion® Blazor for server-side in .NET Core CLI