Getting Started with Blazor DropDown List Component in Blazor Web App

29 May 202611 minutes to read

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

• Visual Studio
• Visual Studio Code
• .NET CLI

Prerequisites

• System requirements for Blazor components

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

• System requirements for Blazor components

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+`):

Blazor Web App

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, determine the installed version by executing the following command in a command prompt (Windows) or terminal (macOS/Linux).

.NET CLI

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:

Blazor Web App

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

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 the Syncfusion.Blazor.DropDowns and Syncfusion.Blazor.Themes NuGet packages using one of the following methods.

Visual Studio (NuGet Package Manager):

1. Go to Tools → NuGet Package Manager → Manage NuGet Packages for Solution.
2. Search the required NuGet packages (Syncfusion.Blazor.DropDowns and Syncfusion.Blazor.Themes) and install it.

Visual Studio Code or .NET CLI:

Open the terminal or command prompt and run the following commands:

.NET CLI

dotnet add package Syncfusion.Blazor.DropDowns -v 33.2.3
dotnet add package Syncfusion.Blazor.Themes -v 33.2.3

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.

~/_Imports.razor

@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.

Program.cs

....
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 DropDown List component

• Open a Razor file located in the ~/Components/Pages (for example, Home.razor) and add the Blazor DropDown List component inside the 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 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.

Home.razor

@rendermode InteractiveAuto
@using Syncfusion.Blazor.DropDowns

<SfDropDownList TValue="string" TItem="string" Placeholder="Select a game"></SfDropDownList>

Run the application

Visual Studio:

• Press Ctrl+F5 (Windows) or ⌘+F5 (macOS) to launch the application. The Blazor DropDown List component will render in your default web browser.

Visual Studio Code or .NET CLI:

1. Open the terminal (Visual Studio Code) or command prompt (.NET CLI) and navigate to the Client project folder.

2. Run the following command:

    dotnet run
   

3. The application will start and display in your default web browser.

Binding data source

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

Home.razor

@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"},
  };
}

Configure the popup list

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

Home.razor

@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"},
  };
}

Get selected value

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

Home.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 object list of the selected value in the ValueChange event using the ChangeEventArgs.ItemData property.

Home.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}");
    }
}

NOTE

View Sample in GitHub.

See also

1. Getting Started with Syncfusion^® Blazor Web Assembly App in Visual Studio or .NET CLI
2. Getting Started with Syncfusion^® Blazor Web App in Visual Studio or .NET CLI