The class encapsulates the event data for the various TreeView.BeforeXXX events. You can determine the Action that caused the event and the Node that will be modified. If you wish to abort the action, you can set the Cancel property.

public class TreeViewCancelEventArgs : System.ComponentModel.CancelEventArgs {
// Public Constructors
   public TreeViewCancelEventArgs(TreeNode node, bool cancel, TreeViewAction action);
// Public Instance Properties
   public TreeViewAction Action{get; }
   public TreeNode Node{get; }
}

Hierarchy

System.Object System.EventArgs System.ComponentModel.CancelEventArgs TreeViewCancelEventArgs

Passed To

TreeView.{OnBeforeCheck(), OnBeforeCollapse(), OnBeforeExpand(), OnBeforeSelect()}, TreeViewCancelEventHandler.{BeginInvoke(), Invoke()}