How to: Iterate Through Nodes via the Node Iterator

  • 6 minutes to read

This example shows how to traverse through all visible nodes to expand those nodes that have more than four child nodes. Nodes that have less than four child nodes are collapsed.

<Window xmlns:dxg="clr-namespace:DevExpress.Xpf.Grid;assembly=DevExpress.Xpf.Grid.v11.1"  x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
        dx:ThemeManager.ThemeName="Office2007Black"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <dxg:GridControl Name="grid" Loaded="grid_Loaded">
            <dxg:GridControl.Columns>
                <dxg:GridColumn FieldName="Name"/>
                <dxg:GridColumn FieldName="Department"/>
                <dxg:GridColumn FieldName="Position"/>
            </dxg:GridControl.Columns>
            <dxg:GridControl.View>
                <dxg:TreeListView Name="treeListView" AutoWidth="True"
                                  KeyFieldName="ID" ParentFieldName="ParentID"/>
            </dxg:GridControl.View>
        </dxg:GridControl>
    </Grid>
</Window>
using System;
using System.Collections.Generic;

public class Employee {
    public int ID { get; set; }
    public int ParentID { get; set; }
    public string Name { get; set; }
    public string Position { get; set; }
    public string Department { get; set; }
}

public static class Stuff {
    public static List<Employee> GetStuff() {
        List<Employee> stuff = new List<Employee>();
        stuff.Add(new Employee() { ID = 1, ParentID = 0, Name = "Gregory S. Price", Department = "", Position = "President" });
        stuff.Add(new Employee() { ID = 2, ParentID = 1, Name = "Irma R. Marshall", Department = "Marketing", Position = "Vice President" });
        stuff.Add(new Employee() { ID = 3, ParentID = 1, Name = "John C. Powell", Department = "Operations", Position = "Vice President" });
        stuff.Add(new Employee() { ID = 4, ParentID = 1, Name = "Christian P. Laclair", Department = "Production", Position = "Vice President" });
        stuff.Add(new Employee() { ID = 5, ParentID = 1, Name = "Karen J. Kelly", Department = "Finance", Position = "Vice President" });

        stuff.Add(new Employee() { ID = 6, ParentID = 2, Name = "Brian C. Cowling", Department = "Marketing", Position = "Manager" });
        stuff.Add(new Employee() { ID = 7, ParentID = 2, Name = "Thomas C. Dawson", Department = "Marketing", Position = "Manager" });
        stuff.Add(new Employee() { ID = 8, ParentID = 2, Name = "Angel M. Wilson", Department = "Marketing", Position = "Manager" });
        stuff.Add(new Employee() { ID = 9, ParentID = 2, Name = "Bryan R. Henderson", Department = "Marketing", Position = "Manager" });

        stuff.Add(new Employee() { ID = 10, ParentID = 3, Name = "Harold S. Brandes", Department = "Operations", Position = "Manager" });
        stuff.Add(new Employee() { ID = 11, ParentID = 3, Name = "Michael S. Blevins", Department = "Operations", Position = "Manager" });
        stuff.Add(new Employee() { ID = 12, ParentID = 3, Name = "Jan K. Sisk", Department = "Operations", Position = "Manager" });
        stuff.Add(new Employee() { ID = 13, ParentID = 3, Name = "Sidney L. Holder", Department = "Operations", Position = "Manager" });

        stuff.Add(new Employee() { ID = 14, ParentID = 4, Name = "James L. Kelsey", Department = "Production", Position = "Manager" });
        stuff.Add(new Employee() { ID = 15, ParentID = 4, Name = "Howard M. Carpenter", Department = "Production", Position = "Manager" });
        stuff.Add(new Employee() { ID = 16, ParentID = 4, Name = "Jennifer T. Tapia", Department = "Production", Position = "Manager" });

        stuff.Add(new Employee() { ID = 17, ParentID = 5, Name = "Judith P. Underhill", Department = "Finance", Position = "Manager" });
        stuff.Add(new Employee() { ID = 18, ParentID = 5, Name = "Russell E. Belton", Department = "Finance", Position = "Manager" });
        return stuff;
    }
}
using System.Windows;
using DevExpress.Xpf.Grid;

namespace WpfApplication1 {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
            grid.ItemsSource = Stuff.GetStuff();
        }

        private void SmartExpandNodes(int minChildCount) {
            TreeListNodeIterator nodeIterator = new TreeListNodeIterator(treeListView.Nodes, true);
            while (nodeIterator.MoveNext())
                nodeIterator.Current.IsExpanded = nodeIterator.Current.Nodes.Count >= minChildCount;
        }

        private void grid_Loaded(object sender, RoutedEventArgs e) {
            SmartExpandNodes(4);
        }
    }
}