How to Populate Nodes Without Binding Data as Unbound Mode in WPF TreeView?

This repository describes how to populate nodes without binding data as unbound mode in WPF TreeView (SfTreeview).

You can create and manage the TreeViewNode objects by yourself to display the data in a hierarchical view. To create a tree view, you use a TreeView control and a hierarchy of TreeViewNode objects. You create the node hierarchy by adding one or more root nodes to the SfTreeView.Nodes collection. Each TreeViewNode can have more nodes added to its Children collection. You can nest tree view nodes to whatever depth you require.

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:GettingStarted"
        xmlns:Syncfusion="http://schemas.syncfusion.com/wpf" xmlns:Engine="clr-namespace:Syncfusion.UI.Xaml.TreeView.Engine;assembly=Syncfusion.SfTreeView.WPF" x:Class="GettingStarted.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Syncfusion:SfTreeView HorizontalAlignment="Left" Height="414" Margin="318,0,0,0" VerticalAlignment="Center" Width="250">
            <Syncfusion:SfTreeView.Nodes>
                <Engine:TreeViewNode Content="Grains" IsExpanded="True">
                    <Engine:TreeViewNode.ChildNodes>
                        <Engine:TreeViewNode Content="Cereals" IsExpanded="True">
                            <Engine:TreeViewNode.ChildNodes>
                                <Engine:TreeViewNode Content="Rice"/>
                                <Engine:TreeViewNode Content="Barley"/>
                            </Engine:TreeViewNode.ChildNodes>
                        </Engine:TreeViewNode>
                        <Engine:TreeViewNode Content="Oilseeds">
                            <Engine:TreeViewNode.ChildNodes>
                                <Engine:TreeViewNode Content="Safflower"/>
                            </Engine:TreeViewNode.ChildNodes>
                        </Engine:TreeViewNode>
                    </Engine:TreeViewNode.ChildNodes>
                </Engine:TreeViewNode>
                <Engine:TreeViewNode Content="Fruits" IsExpanded="true">
                    <Engine:TreeViewNode.ChildNodes>
                        <Engine:TreeViewNode Content="Orange"/>
                        <Engine:TreeViewNode Content="Apples" IsExpanded="true"/>
                    </Engine:TreeViewNode.ChildNodes>
                </Engine:TreeViewNode>
                <Engine:TreeViewNode Content="Vegetables" IsExpanded="true">
                    <Engine:TreeViewNode.ChildNodes>
                        <Engine:TreeViewNode Content="Root Vegetables" IsExpanded="true">
                            <Engine:TreeViewNode.ChildNodes>
                                <Engine:TreeViewNode Content="Potato"/>
                                <Engine:TreeViewNode Content="Carrot"/>
                            </Engine:TreeViewNode.ChildNodes>
                        </Engine:TreeViewNode>
                        <Engine:TreeViewNode Content="Podded">
                            <Engine:TreeViewNode.ChildNodes>
                                <Engine:TreeViewNode Content="Peanut"/>
                                <Engine:TreeViewNode Content="Lentil"/>
                            </Engine:TreeViewNode.ChildNodes>
                        </Engine:TreeViewNode>
                    </Engine:TreeViewNode.ChildNodes>
                </Engine:TreeViewNode>
            </Syncfusion:SfTreeView.Nodes>
        </Syncfusion:SfTreeView>
    </Grid>
</Window>