Key events Code Example-P-4

Keyboard Events
Windows Forms provides two events that occur when a user presses a keyboard key and one event when a user releases a keyboard key:
The KeyDown event occurs once
The KeyPress event, which can occur multiple times when a user holds down the same key.
The KeyUp event occurs once when a user releases a key.
When a user presses a key, Windows Forms determines which event to raise based on whether the keyboard message specifies a character key or a physical key. For more information about character and physical keys,
KeyDown
This event is raised when a user presses a physical key.
The handler for KeyDown receives:
• A KeyEventArgs parameter, which provides the KeyCode property (which specifies a physical keyboard button).
• The Modifiers property (SHIFT, CTRL, or ALT).
• The KeyData property (which combines the key code and modifier). The KeyEventArgs parameter also provides:
KeyPress
This event is raised when the key or keys pressed result in a character. For example, a user presses SHIFT and the lowercase "a" keys, which result in a capital letter "A" character.
• The handler for KeyPress receives:
• A KeyPressEventArgs parameter, which contains the character code of the key that was pressed. This character code is unique for every combination of a character key and a modifier key.