The HelpButtonClicked event occurs when the Help button in the form's caption bar is clicked. The Help button is displayed when the HelpButton property is set to true. HelpButtonClicked can be canceled.

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 HelpButtonClicked 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 Form named Form1. Then ensure that the event handler is associated with the HelpButtonClicked event.

Private Sub Form1_HelpButtonClicked(sender as Object, e as CancelEventArgs) _ 
     Handles Form1.HelpButtonClicked

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "Cancel", e.Cancel)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"HelpButtonClicked Event")

End Sub

private void Form1_HelpButtonClicked(Object sender, CancelEventArgs e) {

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

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference