Forms of common events
Events can be understood as the user's actions, such as clicking the mouse and keyboard
Applications need to respond to events as they occur, so the event is divided into:
Event registration: will be executed for the object must register an event (such as adding a click event for a control)
Triggering Event: event after registration must take place before the trigger (such as when the user clicks the control to trigger the event)
Quick add events:
Select a control panel to open the event, double-click in a blank space behind the event.
Common attributes: Click MouseDown KeyDown and so is generally based on the literal meaning to understand the significance of events