BeforeCheck Event

Occurs before the CheckedState of a node is changed.

Syntax

Visual Basic

'Declaration
 
Public Event BeforeCheck As BeforeCheckEventHandler

C#

public event BeforeCheckEventHandler BeforeCheck

Event Data

The event handler receives an argument of type BeforeCheckEventArgs containing data related to this event. The following BeforeCheckEventArgs properties provide information specific to this event.

Property	Description
Cancel (Inherited from System.ComponentModel.CancelEventArgs)
NewValue	Gets/sets the new value of the node's checkbox.
TreeNode (Inherited from Infragistics.Win.UltraWinTree.CancelableNodeEventArgs)	The UltraTreeNode (read-only)

Remarks

The CancelableNodeEventArgs.TreeNode property of the CancelableNodeEventArgs contains a reference to UltraTreeNode whose CheckedState is about to change.

Setting the System.ComponentModel.CancelEventArgs.Cancel property to true will prevent the CheckedState of the UltraTreeNode from changing.

The BeforeCheckEventArgs.NewValue parameter gets/sets the new value of the CheckedState property of the UltraTreeNode.

This event applies only to nodes whose Override.NodeStyle is set to CheckBox, CheckBoxTripleState, or OptionButton.

Example

The following sample code illustrates some of the information available in the BeforeCheck event.

For an overview of how to handle events in Visual Basic or Visual C#, see Event Handlers in Visual Basic and Visual C#. For specific information and code examples illustrating how to consume events in your application, see Consuming Events in the .NET Framework Developer's Guide.

Visual Basic

Imports Infragistics.Win.UltraWinTree

Private Sub ultraTree1_BeforeCheck(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinTree.BeforeCheckEventArgs) Handles ultraTree1.BeforeCheck

    Dim sb As New System.Text.StringBuilder()

    sb.Append("Node: ")
    sb.Append(e.TreeNode.Key)
    sb.Append(" check state is about to change from ")
    sb.Append(e.TreeNode.CheckedState)
    sb.Append(" to ")
    sb.Append(e.NewValue)

    Debug.WriteLine(sb.ToString())

    ' Note : This action can be canceled by the following line of code.
    'e.Cancel = True

End Sub

C#

using System.Diagnostics;
using Infragistics.Win.UltraWinTree;

private void ultraTree1_BeforeCheck(object sender, Infragistics.Win.UltraWinTree.BeforeCheckEventArgs e)
{

	System.Text.StringBuilder sb = new System.Text.StringBuilder();

	sb.Append("Node: ");
	sb.Append(e.TreeNode.Key);
	sb.Append(" check state is about to change from ");
	sb.Append(e.TreeNode.CheckedState);
	sb.Append(" to ");
	sb.Append(e.NewValue);

	Debug.WriteLine( sb.ToString() );
		
	// Note : This action can be canceled by the following line of code.
	//e.Cancel = true;

}

Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2