Getting Started with ASP.NET MVC DropDownTree Control

30 May 20227 minutes to read

This section briefly explains about how to include ASP.NET MVC DropDownTree control in your ASP.NET MVC application using Visual Studio.

Prerequisites

System requirements for ASP.NET MVC controls

Create ASP.NET MVC application with HTML helper

Install ASP.NET MVC package in the application

Syncfusion ASP.NET MVC controls are available in nuget.org. Refer to NuGet packages topic to learn more about installing NuGet packages in various OS environments. To add ASP.NET MVC controls in the application, open the NuGet package manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), search for Syncfusion.EJ2.MVC5 and then install it.

The Syncfusion.EJ2.MVC5 NuGet package has dependencies, Newtonsoft.Json for JSON serialization and Syncfusion.Licensing for validating Syncfusion license key.

If you create ASP.NET MVC application with MVC4 package, search for Syncfusion.EJ2.MVC4 and then install it.

Add namespace

Add Syncfusion.EJ2 namespace reference in Web.config under Views folder.

<namespaces>
    <add namespace="Syncfusion.EJ2"/>
</namespaces>

Add style sheet

Checkout the Themes topic to learn different ways (CDN, NPM package, and CRG) to refer styles in ASP.NET MVC application, and to have the expected appearance for Syncfusion ASP.NET MVC controls. Here, the theme is referred using CDN inside the <head> of ~/Views/Shared/_Layout.cshtml file as follows,

<head>
    ...
    <!-- Syncfusion ASP.NET MVC controls styles -->
    <link rel="stylesheet" href="https://cdn.syncfusion.com/ej2/20.2.36/fluent.css" />
</head>

Add script reference

In this getting started walk-through, the required scripts are referred using CDN inside the <head> of ~/Views/Shared/_Layout.cshtml file as follows,

<head>
    ...
    <!-- Syncfusion ASP.NET MVC controls scripts -->
    <script src="https://cdn.syncfusion.com/ej2/20.2.36/dist/ej2.min.js"></script>
</head>

Register Syncfusion Script Manager

Open ~/Views/Shared/_Layout.cshtml page and register the script manager EJS().ScriptManager() at the end of <body> in the ASP.NET MVC application as follows.

<body>
...
    <!-- Syncfusion ASP.NET MVC Script Manager -->
    @Html.EJS().ScriptManager()
</body>

Add ASP.NET MVC DropDownTree control

Now, add the Syncfusion ASP.NET MVC DropDownTree control in ~/Views/Home/Index.cshtml page.

@Html.EJS().DropDownTree("data").Render()

Press Ctrl+F5 (Windows) or +F5 (macOS) to run the app. Then, the Syncfusion ASP.NET MVC DropDownTree control will be rendered in the default web browser.

ASP.NET MVC DropDownTree Control

Binding data source

The Dropdown Tree control can load data either the from local data sources or remote data services. This can be done using the dataSource property that is a member of the Fields property. The dataSource property supports nested list of data and DataManager. Here, nested list of data is passed to the Dropdown Tree control.

@model List<DropDownTreeSample.Controllers.Parent>
@{
    .....
    char[] value = { 'n', 'o', 'd', 'e', 'C', 'h', 'i', 'l', 'd' };
    string child = new string(value);
}

<div id='container' style="margin:0 auto; width:250px;">
    @Html.EJS().DropDownTree("treedata").Placeholder("Select a Item").Fields(field =>
                field.Value("nodeId").Child(child).Text("nodeText").DataSource(Model)).Render()
</div>
public class HomeController : Controller
{
    public ActionResult Index()
    {
        List<Parent> parentitem = new List<Parent>();
        List<Child> childitem = new List<Child>();
        parentitem.Add(new Parent
        {
            nodeId = "01",
            nodeText = "Music",
            nodeChild = childitem,
        });
        childitem.Add(new Child { nodeId = "01-01", nodeText = "Gouttes.mp3" });

        List<Child> childitem2 = new List<Child>();
        parentitem.Add(new Parent
        {
            nodeId = "02",
            nodeText = "Videos",
            expanded = true,
            nodeChild = childitem2,
        });
        childitem2.Add(new Child { nodeId = "02-01", nodeText = "Naturals.mp4" });
        childitem2.Add(new Child { nodeId = "02-02", nodeText = "Wild.mpeg" });
        List<Child> childitem3 = new List<Child>();
        parentitem.Add(new Parent
        {
            nodeId = "03",
            nodeText = "Documents",
            nodeChild = childitem3,
        });
        childitem3.Add(new Child { nodeId = "03-01", nodeText = "Environment Pollution.docx" });
        childitem3.Add(new Child { nodeId = "03-02", nodeText = "Global Water, Sanitation, & Hygiene.docx" });
        childitem3.Add(new Child { nodeId = "03-03", nodeText = "Global Warming.ppt" });
        childitem3.Add(new Child { nodeId = "03-04", nodeText = "Social Network.pdf" });
        childitem3.Add(new Child { nodeId = "03-05", nodeText = "Youth Empowerment.pdf" });
        //ViewBag.dataSource = parentitem;            
        return View(parentitem);
    }
    ....
}
public class Parent
{
    public string nodeId;
    public string nodeText;
    public string icon;
    public bool expanded;
    public bool selected;
    public List<Child> nodeChild;
}
public class Child
{
    public string nodeId;
    public string nodeText;
    public string icon;
    public bool expanded;
    public bool selected;
    public List<Child> nodeChild;
}

ASP.NET MVC DropDownTree with Childnode

View Sample in GitHub.