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Getting Started with Dropdown List Component

16 Apr 202610 minutes to read

This guide briefly explains how to include Syncfusion® Blazor DropDownList component in a Blazor WebAssembly App using Visual Studio, Visual Studio Code, and the .NET CLI. Ensure a valid Syncfusion license is registered in the application and choose a theme (Bootstrap, Fluent, Material, or Tailwind) as part of setup.

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.

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 BlazorApp

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 --version

Create 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 the Blazor WASM App Getting Started documentation.

dotnet new blazorwasm -o BlazorApp
cd BlazorApp

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 33.2.3
Install-Package Syncfusion.Blazor.Themes -Version 33.2.3

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 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 WebAssembly App.

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

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 ~/index.html 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 the Blazor application. Also, check out the Adding Script Reference topic to learn different approaches for adding script references in the Blazor application.

Add Syncfusion® Blazor DropDown List component

Add the Syncfusion® Blazor DropDown List component in the ~/Pages/Index.razor file.

@using Syncfusion.Blazor.DropDowns

<SfDropDownList TValue="string" TItem="string" Placeholder="Select a game"></SfDropDownList>
  • Press Ctrl+F5 (Windows) or ⌘+F5 (macOS) to launch the application. The Syncfusion® Blazor DropDownList component renders in the default web browser.
Blazor DropDownList Component

NOTE

View sample in GitHub.

Binding data source

After initialization, populate the DropDownList with data using the DataSource property.

@using Syncfusion.Blazor.DropDowns

<SfDropDownList TValue="string" TItem="Games" Placeholder="Select a game" DataSource="@LocalData">
  <DropDownListFieldSettings Value="ID" Text="Text"></DropDownListFieldSettings>
</SfDropDownList>

@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 DropDownList

Configure the popup list

By default, the popup list width automatically adjusts to the DropDownList input width, and the popup list height is 350px. Customize the height and width using the PopupHeight and PopupWidth properties.

@using Syncfusion.Blazor.DropDowns

<SfDropDownList TValue="string" TItem="Games" PopupHeight="350px" PopupWidth="350px" Placeholder="Select a game" DataSource="@LocalData">
  <DropDownListFieldSettings Value="ID" Text="Text"></DropDownListFieldSettings>
</SfDropDownList>

@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"},
  };
}
Changing Popup List Height in Blazor DropDownList

Get selected value

Get the selected value of the DropDownList component in the ValueChange event using the ChangeEventArgs.Value property.

  • Index.razor
    • @using Syncfusion.Blazor.DropDowns

<SfDropDownList TValue="string" TItem="Games" Placeholder="Select a game" DataSource="@LocalData">
  <DropDownListFieldSettings Value="Text" Text="Text"></DropDownListFieldSettings>
  <DropDownListEvents TValue="string" TItem="Games" ValueChange="OnValueChange"></DropDownListEvents>
</SfDropDownList>

@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"},
  };
    public void OnValueChange(ChangeEventArgs<string, Games> args)
    {
        Console.WriteLine($"The DropDownList Value is: {args.Value}");
    }
}

    Get the complete data object for the selected value in the ValueChange event using the ChangeEventArgs.ItemData property.

  • Index.razor
    • @using Syncfusion.Blazor.DropDowns

<SfDropDownList TValue="string" TItem="Games" Placeholder="Select a game" DataSource="@LocalData">
  <DropDownListFieldSettings Value="ID" Text="Text"></DropDownListFieldSettings>
  <DropDownListEvents TValue="string" TItem="Games" ValueChange="OnValueChange"></DropDownListEvents>
</SfDropDownList>

@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"},
  };
    public void OnValueChange(ChangeEventArgs<string, Games> args)
    {
        Console.WriteLine($"Selected - ID: {args.ItemData.ID}, Game: {args.ItemData.Text}");
    }
}

    See also