Check Nodes

• Mar 01, 2024
• 4 minutes to read

You can embed check boxes into nodes and allow an end user to check/uncheck them:

Run Demo: Node Check Boxes

To Embed Check Boxes into Nodes

1. Set the TreeListView.ShowCheckboxes property to true to display check boxes embedded into nodes.

2. Set values of check boxes. Do one of the following:

   • Specify the TreeListView.CheckBoxFieldName property to bind check boxes to a Boolean field in the grid’s data source.
   • Check nodes in code.

The code sample below shows how to display check boxes and bind them to the OnVacation field:

Xaml

<dxg:GridControl Name="gridControl">
    <dxg:GridControl.Columns>
        <dxg:GridColumn FieldName="Name"/>
        <dxg:GridColumn FieldName="Department"/>
        <dxg:GridColumn FieldName="Position"/>
    </dxg:GridControl.Columns>
    <dxg:GridControl.View>
        <dxg:TreeListView KeyFieldName="ID" ParentFieldName="ParentID" AutoExpandAllNodes="True"
            ShowCheckboxes="True" CheckBoxFieldName="OnVacation" />
    </dxg:GridControl.View>
</dxg:GridControl>

C#

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 bool OnVacation { get; set; }
}

VB.NET

Public Class Employee
    Public Property ID As Integer
    Public Property ParentID As Integer
    Public Property Name As String
    Public Property Position As String
    Public Property Department As String
    Public Property OnVacation As Boolean
End Class 

Note

The TreeListView does not post the focused row’s check box value until you focus another row. To make the TreeListView post check box values immediately, set the TreeListView.ImmediateUpdateCheckBoxState property to true.

Check Nodes in Code

Use the following members to check/uncheck nodes in code:

Method	Description
TreeListView.CheckAllNodes	Checks all nodes.
TreeListView.UncheckAllNodes	Unchecks all nodes.
TreeListNode.IsChecked	Checks/unchecks the node.

When a node’s check state is changed, the TreeListView raises the TreeListView.NodeCheckStateChanged event. Use the TreeListNode.IsChecked property to identify whether a node is checked.

Indeterminate State

Set the TreeListView.AllowIndeterminateCheckState property to true to allow an end user to set the node’s check box to one of three states (checked, unchecked, or indeterminate):

Tip

In this case, a user can specify a check box’s state despite the states of its parents and children. Refer to the Check Nodes Recursively section for information on how to update check states automatically based on child and parent node selection.

The TreeListNode.IsChecked property returns the following values:

• true - if a node is checked
• false - if a node is unchecked
• null - if a node is indeterminated

Check Nodes Recursively

Set the TreeListView.AllowRecursiveNodeChecking property to true if you want the control to update check states automatically based on child and parent node selection:

• When you check/uncheck a parent node, its children become checked/unchecked.
• When you check/uncheck all child nodes, its parent becomes checked/unchecked.
• When you check/uncheck a child node, but not all child nodes are checked/unchecked, its parent goes to the indeterminate check state.

Enabled State

Use the following properties to bind the enabled state of check boxes to a property:

Property	Description
TreeListView.IsCheckBoxEnabledFieldName	Gets or sets the name of a data source’s field whose values determine whether a node’s check box is enabled.
TreeListView.IsCheckBoxEnabledBinding	Gets or sets the binding that determines whether a node’s check box is enabled.

Note

The TreeListView.IsCheckBoxEnabledBinding property takes precedence over the TreeListView.IsCheckBoxEnabledFieldName property.

The code sample below shows how to bind the enabled state of check boxes to the Enabled field:

Xaml

<dxg:GridControl Name="gridControl">
    <dxg:GridControl.Columns>
        <dxg:GridColumn FieldName="Name"/>
        <dxg:GridColumn FieldName="Department"/>
        <dxg:GridColumn FieldName="Position"/>
    </dxg:GridControl.Columns>
    <dxg:GridControl.View>
        <dxg:TreeListView KeyFieldName="ID" ParentFieldName="ParentID" AutoExpandAllNodes="True"
                          ShowCheckboxes="True" CheckBoxFieldName="OnVacation" IsCheckBoxEnabledFieldName="Enabled" />
    </dxg:GridControl.View>
</dxg:GridControl>

C#

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 bool OnVacation { get; set; }
    public bool Enabled { get; set; }
}

VB.NET

Public Class Employee
    Public Property ID As Integer
    Public Property ParentID As Integer
    Public Property Name As String
    Public Property Position As String
    Public Property Department As String
    Public Property OnVacation As Boolean
    Public Property Enabled As Boolean
End Class