OnBeforeCollapse Method

Called before a node is collapsed

Syntax

Visual Basic

'Declaration
 
Protected Overridable Sub OnBeforeCollapse( _
   ByVal e As CancelableNodeEventArgs _
) 

C#

protected virtual void OnBeforeCollapse( 
   CancelableNodeEventArgs e
)

Parameters

e

An System.EventArgs that contains the event data.

Example

The following sample code illustrates some of the information available in the BeforeCollapse 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_BeforeCollapse(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinTree.CancelableNodeEventArgs) Handles ultraTree1.BeforeCollapse

    Dim sb As New System.Text.StringBuilder()

    sb.Append("Node: ")
    sb.Append(e.TreeNode.Key)
    sb.Append(" is about to be collapsed.")

    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_BeforeCollapse(object sender, Infragistics.Win.UltraWinTree.CancelableNodeEventArgs e)
{

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

	sb.Append("Node: ");
	sb.Append(e.TreeNode.Key);
	sb.Append(" is about to be collapsed.");

	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