Getting Started with Blazor TreeView in Blazor Web App

16 Feb 20245 minutes to read

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

Prerequisites

System requirements for Blazor components

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 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 27.2.2
Install-Package Syncfusion.Blazor.Themes -Version 27.2.2

NOTE

Syncfusion Blazor components are available in nuget.org. 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.Navigations namespace .

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

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;
....
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 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>
</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 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:

RAZOR

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

RAZOR
<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.