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 Invalidated 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 a type that inherits from Control, such as a Button or ComboBox. Then name the instance Control1 and ensure that the event handler is associated with the Invalidated event.

Private Sub Control1_Invalidated(sender as Object, e as InvalidateEventArgs) _ 
     Handles Control1.Invalidated

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

End Sub

private void Control1_Invalidated(Object sender, InvalidateEventArgs e) {

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

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

.NET Framework

Reference