Getting Started with Blazor TreeView in Blazor Web App

16 Sep 202511 minutes to read

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

• Visual Studio
• Visual Studio Code
• .NET CLI

Prerequisites

• System requirements for Blazor components

Create a new Blazor Web App in Visual Studio

You can create a Blazor Web App using Visual Studio 2022 via Microsoft Templates or the Syncfusion^® Blazor Extension. For detailed instructions, refer to this Blazor Web App Getting Started documentation.

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

Install Syncfusion^® Blazor Navigations and Themes NuGet in the App

To add Blazor TreeView 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.Navigations 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.

Package Manager

Install-Package Syncfusion.Blazor.Navigations -Version 31.1.17
Install-Package Syncfusion.Blazor.Themes -Version 31.1.17

NOTE

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

Prerequisites

• System requirements for Blazor components

Create a new Blazor Web App in Visual Studio Code

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

Configure the appropriate interactive render mode and interactivity location when setting up a Blazor Web Application. For detailed information, refer to the interactive render mode 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

For more information on creating a Blazor Web App with various interactive modes and locations, refer to this link.

Install Syncfusion^® Blazor Navigations and Themes NuGet in the App

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.

• Press Ctrl+` to open the integrated terminal in Visual Studio Code.
• Ensure you’re in the project root directory where your .csproj file is located.
• Run the following command to install a Syncfusion.Blazor.Navigations and Syncfusion.Blazor.Themes NuGet package and ensure all dependencies are installed.

Package Manager

dotnet add package Syncfusion.Blazor.Navigations -v 31.1.17
dotnet add package Syncfusion.Blazor.Themes -v 31.1.17
dotnet restore

NOTE

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

Prerequisites

Latest version of the .NET Core 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).

.NET CLI

dotnet --version

Create a Blazor Web project 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 this Blazor Web App Getting Started documentation.

Configure the appropriate interactive render mode and interactivity location when setting up a Blazor Web Application. For detailed information, refer to the interactive render mode documentation.

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

.NET CLI

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

This command creates new Blazor Web app project and places it in a new directory called BlazorApp inside your current location. See Create Blazor app topic and dotnet new CLI command topics for more details.

Install Syncfusion^® Blazor Navigations and Themes NuGet in the App

Here’s an example of how to add Blazor Treeview component in the application using the following command in the command prompt (Windows) or terminal (Linux and macOS) to install a Syncfusion.Blazor.Navigations and Syncfusion.Blazor.Themes NuGet package. See Install and manage packages using the dotnet CLI topics for more details.

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.

.NET CLI

dotnet add package Syncfusion.Blazor.Navigations --version 31.1.17
dotnet add package Syncfusion.Blazor.Themes --version 31.1.17
dotnet restore

NOTE

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

Add Import Namespaces

Open the ~/_Imports.razor file from the client project and import the Syncfusion.Blazor and Syncfusion.Blazor.Navigations namespace.

~/_Imports.razor

@using Syncfusion.Blazor
@using Syncfusion.Blazor.Navigations

Register Syncfusion^® Blazor Service

Register the Syncfusion^® Blazor Service in the ~/Program.cs file of your Blazor Web App.

If your Blazor Web App uses WebAssembly or Auto interactive render modes, you must register the Syncfusion^® Blazor service in the ~/Program.cs files of the main server project and associated .Client project.

Server(~/_Program.cs)

...
...
using Syncfusion.Blazor;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents()
    .AddInteractiveWebAssemblyComponents();
builder.Services.AddSyncfusionBlazor();

var app = builder.Build();
....

Client(~/_Program.cs)

...
using Syncfusion.Blazor;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
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 reference in the <head> section and the script reference at the end of the <body> in the ~/Components/App.razor file as shown below:

<head>
    ....
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
</head>

<body>
    ....
    <script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>

    //Blazor TreeView Component script reference.
    <!-- <script src="_content/Syncfusion.Blazor.Navigations/scripts/sf-treeview.min.js" type="text/javascript"></script> -->
</body>

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 TreeView component

Add the Syncfusion^® Blazor TreeView component to a Razor page located under the Pages folder (e.g., Pages/Home.razor) in either the Server or Client project. 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:

Interactivity location	RenderMode	Code
Per page/component	Auto	@rendermode InteractiveAuto
	WebAssembly	@rendermode InteractiveWebAssembly
	None	—

NOTE

If an Interactivity Location is set to Global and the Render Mode is set to Auto or WebAssembly, the render mode is configured in the App.razor file by default.

RAZOR

@* desired render mode define here *@
@rendermode InteractiveAuto

RAZOR

@using Syncfusion.Blazor.Navigations

<SfTreeView TValue="MailItem">
    <TreeViewFieldsSettings TValue="MailItem" Id="Id" DataSource="@MyFolder" Text="FolderName" ParentID="ParentId" HasChildren="HasSubFolders" Expanded="Expanded"></TreeViewFieldsSettings>
</SfTreeView>

@code{
    public class MailItem
    {
        public string? Id { get; set; }
        public string? ParentId { get; set; }
        public string? FolderName { get; set; }
        public bool Expanded { get; set; }
        public bool HasSubFolders { get; set; }
    }
    List<MailItem> MyFolder = new List<MailItem>();
    protected override void OnInitialized()
    {
        base.OnInitialized();
        MyFolder.Add(new MailItem
        {
            Id = "1",
            FolderName = "Inbox",
            HasSubFolders = true,
            Expanded = true
        });
        MyFolder.Add(new MailItem
        {
            Id = "2",
            ParentId = "1",
            FolderName = "Categories",
            Expanded = true,
            HasSubFolders = true
        });
        MyFolder.Add(new MailItem
        {
            Id = "3",
            ParentId = "2",
            FolderName = "Primary"
        });
        MyFolder.Add(new MailItem
        {
            Id = "4",
            ParentId = "2",
            FolderName = "Social"
        });
        MyFolder.Add(new MailItem
        {
            Id = "5",
            ParentId = "2",
            FolderName = "Promotions"
        });
    }
}

• Press Ctrl+F5 (Windows) or ⌘+F5 (macOS) to launch the application. This will render the Syncfusion^® Blazor TreeView component in your default web browser.

NOTE

View Sample in GitHub.

See Also

• Getting Started with Syncfusion^® Blazor for Client-Side in .NET Core CLI
• Getting Started with Syncfusion^® Blazor for Client-Side in Visual Studio
• Getting Started with Syncfusion^® Blazor for Server-Side in .NET Core CLI