BeforeSelect Event

TreeView.BeforeSelect Event


Occurs before the tree node is selected.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public event TreeViewCancelEventHandler BeforeSelect

For more information about how to handle events, see Handling and Raising 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 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 void TreeView1_BeforeSelect(Object sender, TreeViewCancelEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "Node", e.Node );
messageBoxCS.AppendFormat("{0} = {1}", "Action", e.Action );
messageBoxCS.AppendFormat("{0} = {1}", "Cancel", e.Cancel );
MessageBox.Show(messageBoxCS.ToString(), "BeforeSelect Event" );

.NET Framework
Available since 1.1
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