Getting Started with Blazor MultiSelect DropDown in Web App

16 Feb 20245 minutes to read

This section briefly explains about how to include Blazor MultiSelect DropDown component in your Blazor Web App using Visual Studio.


Create a new Blazor Web App

You can create a Blazor Web App using Visual Studio 2022 via Microsoft Templates or the Syncfusion Blazor Extension.

You need to configure the corresponding Interactive render mode and Interactivity location while creating a Blazor Web Application.

Install Syncfusion Blazor DropDowns and Themes NuGet in the App

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

If you utilize WebAssembly or Auto render modes in the Blazor Web App need to be install Syncfusion Blazor components NuGet packages within the client project.

Alternatively, you can utilize the following package manager command to achieve the same.

Install-Package Syncfusion.Blazor.DropDowns -Version 26.1.35
Install-Package Syncfusion.Blazor.Themes -Version 26.1.35


Syncfusion Blazor components are available in Refer to NuGet packages topic for available NuGet packages list with component details.

Register Syncfusion Blazor Service

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

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

Now, register the Syncfusion Blazor Service in the ~/Program.cs file of your Blazor Web App.

If you select an Interactive render mode as WebAssembly or Auto, you need to register the Syncfusion Blazor service in both ~/Program.cs files of your Blazor Web App.

using Syncfusion.Blazor;

Add stylesheet and script resources

The theme stylesheet and script can be accessed from NuGet through Static Web Assets. Include the stylesheet reference in the <head> section and the script reference at the end of the <body> in the ~/Components/App.razor file as shown below:

    <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>


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 MultiSelect DropDown component

Add the Syncfusion Blazor MultiSelect DropDown component in the ~Pages/.razor file. If an interactivity location as Per page/component in the web app, define a render mode at the top of the ~Pages/.razor component, as follows:

@* desired render mode define here *@
@rendermode InteractiveAuto
<SfMultiSelect TValue="string[]" TItem="string" Placeholder='First Name'></SfMultiSelect>
  • Press Ctrl+F5 (Windows) or +F5 (macOS) to launch the application. This will render the Syncfusion Blazor MultiSelect DropDown component in your default web browser.
Blazor MultiSelect DropDown Component


View Sample in GitHub.

Binding data source

After initialization, populate the MultiSelect with data using the DataSource property. Here, an array of string values is passed to the MultiSelect component. TItem specifies the type of the Datasource in MultiSelect.

<SfMultiSelect TValue="string[]" TItem="Games" Placeholder="Favorite Sports" DataSource="@LocalData">
    <MultiSelectFieldSettings Text="Text" Value="ID"></MultiSelectFieldSettings>

@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"},
Data Binding in Blazor MultiSelect DropDown

Configure the popup list

By default, the width of the popup list automatically adjusts according to the MultiSelect input element’s width, and the height auto adjust’s according to the height of the popup list items.

The height and width of the popup list can also be customized using the PopupHeight and PopupWidth properties respectively.

<SfMultiSelect TValue="string[]" TItem="Games" Placeholder="Favorite Sports" PopupHeight="350px" PopupWidth="350px" DataSource="@LocalData">
    <MultiSelectFieldSettings Text="Text" Value="ID"></MultiSelectFieldSettings>
Configuring Popup List in Blazor MultiSelect DropDown

See also