INFO: Windows WM_SYSTIMER Message Is an Undocumented Message

ID: Q108938

The information in this article applies to:

• Microsoft Win32 Software Development Kit (SDK)
• Microsoft Windows Software Development Kit (SDK) version 3.1

SUMMARY

The WM_SYSTIMER message in Windows is an undocumented system message; it should not be trapped or relied on by an application. This message can occasionally be viewed in Spy or in CodeView while debugging.

Windows uses the WM_SYSTIMER message internally to control the scroll rate of highlighted text (text selected by the user) in edit controls, or highlighted items in list boxes.

NOTE: The WM_SYSTIMER message is for Windows's internal use only and can be changed without prior notice.

Additional query words:

Keywords          : kbNTOS kbGrpUser kbWinOS kbWndw kbWndwMsg 
Issue type        : kbinfo

Last Reviewed: December 26, 1998