Understanding Events and Event Handlers
Windows is a message-based, event-driven operating system. Events are simply occurrences that can be almost anything; basic occurrences are things like someone moving a window on the desktop. The movement of a form is an occurrence after which other forms need to be notified, so they can repaint their visible client regions. We refer to such occurrences as events.
At the OS level, an event is usually caused by an interrupt request. When you hit a key on your keyboard, special subprograms called interrupts (in the case of the keyboard, interrupts 9 and 16) are fired internally. The Windows OS detects the interrupt and packages up all the information necessary to describe the interrupt. The package describing ...
Get Visual Basic® .NET Unleashed now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
