TreeViewControl.HasChildNodesPath Property

Gets or sets the name of a data source’s field that determines whether a node has children. This is a dependency property.

Namespace: DevExpress.Xpf.Grid

Assembly: DevExpress.Xpf.Grid.v24.1.dll

NuGet Package: DevExpress.Wpf.Grid.Core

Declaration

C#

public string HasChildNodesPath { get; set; }

VB.NET

Public Property HasChildNodesPath As String

Property Value

Type	Description
String	The name of a data source’s field that determines whether a node has children.

Remarks

The HasChildNodesPath property works only when you specify the ChildNodesPath property.

To build a tree structure, set the ChildNodesPath property to a field that contains child nodes (the Employees field in the code sample below).

XAML

<dxg:TreeViewControl ItemsSource="{Binding EmployeeDepartments}" 
                     ChildNodesPath="Employees" 
                     TreeViewFieldName="Name"
                     HasChildNodesPath="HasChildNodes"/>

C#

using System.Windows;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using DevExpress.Mvvm;

namespace TreeViewChildNodesSelector {
    public class MainWindowViewModel : ViewModelBase {
        public MainWindowViewModel() {
            EmployeeDepartments = Departments.GetDepartments();
        }
        public List<EmployeeDepartment> EmployeeDepartments { get; set; }
    }
    public class Employee {
        public Employee(int id, string name) {
            ID = id;
            Name = name;
        }
        public int ID { get; set; }
        public string Name { get; set; }
    }
    public class EmployeeDepartment {
        public string Name { get; set; }
        public ObservableCollection<Employee> Employees { get; }
        public bool HasChildNodes { get; set; }

        public EmployeeDepartment(string name, IEnumerable<Employee> employees) {
            Name = name;
            Employees = new ObservableCollection<Employee>(employees);
        }
    }
    public static class Departments {
        public static List<EmployeeDepartment> GetDepartments() {
            List<EmployeeDepartment> departments = new List<EmployeeDepartment> {
                new EmployeeDepartment("Management", new Employee[] {
                new Employee(0, "Gregory S. Price")
                }, true),
                new EmployeeDepartment("Marketing", new Employee[] {
                new Employee(1, "Irma R. Marshall"),
                new Employee(2, "Brian C. Cowling"),
                new Employee(3, "Thomas C. Dawson"),
                new Employee(4, "Bryan R. Henderson"),
                }, true),
                new EmployeeDepartment("Operations", new Employee[] {
                new Employee(5, "John C. Powell"),
                new Employee(6, "Harold S. Brandes"),
                new Employee(7, "Jan K. Sisk"),
                new Employee(8, "Sidney L. Holder"),
                }, true),
                new EmployeeDepartment("Production", new Employee[] {
                new Employee(9, "Christian P. Laclair"),
                new Employee(10, "James L. Kelsey"),
                new Employee(11, "Howard M. Carpenter"),
                new Employee(12, "Jennifer T. Tapia"),
                },false),
                new EmployeeDepartment("Finance", new Employee[] {
                new Employee(13, "Karen J. Kelly"),
                new Employee(14, "Judith P. Underhill"),
                new Employee(15, "Russell E. Belton"),
                },false)
            };
            return departments;
        }
    }
}

VB.NET

Imports System.Windows
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
Imports DevExpress.Mvvm

Namespace TreeViewChildNodesSelector
    Public Class MainWindowViewModel
        Inherits ViewModelBase

        Public Sub New()
            EmployeeDepartments = Departments.GetDepartments()
        End Sub

        Public Property EmployeeDepartments As List(Of EmployeeDepartment)
    End Class

    Public Class Employee
        Public Sub New(ByVal id As Integer, ByVal name As String)
            ID = id
            Name = name
        End Sub

        Public Property ID As Integer
        Public Property Name As String
    End Class

    Public Class EmployeeDepartment
        Public Property Name As String
        Public ReadOnly Property Employees As ObservableCollection(Of Employee)
        Public Property HasChildNodes As Boolean

        Public Sub New(ByVal name As String, ByVal employees As IEnumerable(Of Employee))
            Name = name
            Employees = New ObservableCollection(Of Employee)(employees)
        End Sub
    End Class

    Module Departments
        Function GetDepartments() As List(Of EmployeeDepartment)
            Dim departments As List(Of EmployeeDepartment) = New List(Of EmployeeDepartment) From {
                New EmployeeDepartment("Management", New Employee() {New Employee(0, "Gregory S. Price")}, True),
                New EmployeeDepartment("Marketing", New Employee() {New Employee(1, "Irma R. Marshall"), New Employee(2, "Brian C. Cowling"), New Employee(3, "Thomas C. Dawson"), New Employee(4, "Bryan R. Henderson")}, True),
                New EmployeeDepartment("Operations", New Employee() {New Employee(5, "John C. Powell"), New Employee(6, "Harold S. Brandes"), New Employee(7, "Jan K. Sisk"), New Employee(8, "Sidney L. Holder")}, True),
                New EmployeeDepartment("Production", New Employee() {New Employee(9, "Christian P. Laclair"), New Employee(10, "James L. Kelsey"), New Employee(11, "Howard M. Carpenter"), New Employee(12, "Jennifer T. Tapia")}, False),
                New EmployeeDepartment("Finance", New Employee() {New Employee(13, "Karen J. Kelly"), New Employee(14, "Judith P. Underhill"), New Employee(15, "Russell E. Belton")}, False)
            }
            Return departments
        End Function
    End Module
End Namespace