TreeView.BeforeSelect Event
Occurs before the tree node is selected.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
For more information about handling events, see Consuming Events.
The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the BeforeSelect event. This report helps you to learn when the event occurs and can assist you in debugging. To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.
To run the example code, paste it into a project that contains an instance of type TreeView named TreeView1. Then ensure that the event handler is associated with the BeforeSelect event.
Private Sub TreeView1_BeforeSelect(sender as Object, e as TreeViewCancelEventArgs) _ Handles TreeView1.BeforeSelect Dim messageBoxVB as New System.Text.StringBuilder() messageBoxVB.AppendFormat("{0} = {1}", "Node", e.Node) messageBoxVB.AppendLine() messageBoxVB.AppendFormat("{0} = {1}", "Action", e.Action) messageBoxVB.AppendLine() messageBoxVB.AppendFormat("{0} = {1}", "Cancel", e.Cancel) messageBoxVB.AppendLine() MessageBox.Show(messageBoxVB.ToString(),"BeforeSelect Event") End Sub
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.