In this code sample, VFP form registers for receiving the raw input from each and any keyboard type device connected to the computer. That includes keyboards, numeric keypads, keyboard wedge scanners and so on.
The testing is simple. Any text typed in another Windows application (like text editor, spreadsheet, browser) will be duplicated in an EditBox on the VFP form.
Note that this code sample requires VFP9 version of the BINDEVENT() function. The one that can handle Windows messages.
By default, no application receives raw input. For doing that, an application must register a device type it wants to get data from. When registered, an application receives the raw input through the WM_INPUT messages.
User input comes not just from keyboard and mouse, but also from a joystick, a touch screen, a microphone, and other devices collectively known as Human Interface Devices (HIDs).
Global keyboard and mouse hooks can produce similar results.
In case of multiple input devices of same type, the Raw Input API has means to separate the input (i.g. keystrokes, mouse events) by source.
* * *
Curiously: initially I chose registering keystrokes on KeyUps. And switched to KeyDowns after finding that fast typed keystrokes sometimes get released not in the sequence of pressing.
Credits: PHP (4.4.9), an HTML-embedded scripting language,
MySQL (5.1.55-log), the Open Source standard SQL database,
AceHTML Freeware
Version 4, freeware HTML Editor of choice. Hosted by Korax Online Inc.
How to change display settings: screen resolution, screen refresh rate
