Use Custom Node Icons

wijtree allows you to use custom icons to mark the tree nodes. You can also switch icons based on a node's current state. See the Node Icons > Tree sample of the MVC Control Explorer live demos at http://demo.componentone.com/ASPNET/MVCExplorer/tree/Icons.

Create an ASP.NET MVC 5 Wijmo application.
In the Solution Explorer, expand the Views | Shared folder and double-click _Layout.cshtml to open the file.

Add the following markup within the <body> tags of the page.

<div>
        <ul id="tree">
            <li class="folder"><a><span>Folder 1</span></a>
                <ul>
                    <li class="folder"><a><span>Folder 1.1</span></a>
                        <ul>
                            <li class="file"><a><span>File 1.1</span></a></li>
                            <li class="file"><a><span>File 1.2</span></a></li>
                            <li class="file"><a><span>File 1.3</span></a></li>
                            <li class="file"><a><span>File 1.4</span></a></li>
                            <li class="file"><a><span>File 1.5</span></a></li>
                        </ul>
                    </li>
                    <li class="file"><a><span>File 1.2</span></a></li>
                    <li class="file"><a><span>File 1.3</span></a></li>
                    <li class="file"><a><span>File 1.4</span></a></li>
                    <li class="file"><a><span>File 1.5</span></a></li>
                </ul>
            </li>
            <li class="folder"><a><span>Folder 2</span></a>
                <ul>
                    <li class="file"><a><span>File 2.1</span></a></li>
                    <li class="file"><a><span>File 2.2</span></a></li>
                    <li class="file"><a><span>File 2.3</span></a></li>
                    <li class="file"><a><span>File 2.4</span></a></li>
                    <li class="file"><a><span>File 2.5</span></a></li>
                </ul>
            </li>
            <li class="folder"><a><span>Folder 3</span></a>
                <ul>
                    <li class="file"><a><span>File 3.1</span></a></li>
                    <li class="file"><a><span>File 3.2</span></a></li>
                    <li class="file"><a><span>File 3.3</span></a></li>
                    <li class="file"><a><span>File 3.4</span></a></li>
                    <li class="file"><a><span>File 3.5</span></a></li>
                </ul>
            </li>
        </ul>
    </div>

Add the following script to initialize the widget.

<script id="scriptInit" type="text/javascript">
        $(document).ready(function () {
            $("#tree").wijtree();
            $("li.folder").wijtreenode("option", "collapsedIconClass", "ui-icon-folder-collapsed")
                .wijtreenode("option", "expandedIconClass", "ui-icon-folder-open");
            $("li.file").wijtreenode("option", "itemIconClass", "ui-icon-document");
        });      
    </script>

Run your program. When you click on a node, observe how the file icon changes. It should resemble the following image.