INFO: Journal Hooks and Compatibility
PSS ID Number: 106717
Article Last Modified on 5/6/2003
The information in this article applies to:
- Microsoft Win32 Application Programming Interface (API), when used with:
- the operating system: Microsoft Windows NT 3.1
- the operating system: Microsoft Windows NT 3.5
- the operating system: Microsoft Windows 2000
This article was previously published under Q106717
SUMMARY
Journal hooks are used to record and play back events, such as keyboard and
mouse events. Journal hooks are system-wide hooks that take control of all
user input, and therefore should be used as little as possible.
MORE INFORMATION
Note that Windows NT does not ship with a Recorder application, as Windows
3.1 does. Therefore, it may be desirable to create an application that can
play back macros recorded under Windows 3.1. However, there are a number of
different problems with the Windows NT implementation of journaling that
make it difficult to use macros recorded under Windows 3.1.
The EVENTMSG structures recorded under Windows 3.1 that hold keystrokes do
not play back under Windows NT. They must be modified, because the journal
playback hook parses a scan code out of the EVENTMSG structure differently
than the Windows 3.1 journal record hook put it in the structure. Under
Windows 3.1, paramH specifies the repeat count. Under Windows NT, there is
no way to specify a repeat count; it is always assumed to be 1.
For more information on hooks, please see the Hooks Overview in Volume 1 of
the Win32 "Programmer's Reference" and the article "Win32 Hooks" included
in the MSDN CD #5.
Keywords: kbHook kbinfo KB106717
Technology: kbAudDeveloper kbOSWin2000 kbOSWinNT310 kbOSWinNT350 kbOSWinNTSearch kbOSWinSearch kbWin32API kbWin32sSearch