Ivor Horton's Beginning Visual C++®2008

Appendix C. Windows Message Types

The Windows operating system defines the type of system message that it sends to your application by a symbolic constant such as WM_PAINT. The symbolic constant is composed of two parts: a prefix, WM in this case, that identifies the type of window that can process the message, and the rest, PAINT in this case, that specifies what the window should do when the message is received. The following table shows the message prefixes and the corresponding target window category.

Message Prefix	Target Window Type
ABM	Application desktop toolbar control
BM	Button control
CB	Combo box control
CBEM	Extended combo box control
CDM	Common dialog box control
DBT	Device
DL	Drag list box control
DM	Default push button control
DTM	Date and time picker control
EM	Edit control
HDM	Header control
HKM	Hot key control
IPM	IP address control
LB	List box control
LVM	List view control
MCM	Month calendar control
PBM	Progress bar control
PGM	Pager control
PSM	Property sheet
RB	Rebar control
SB	Status bar control
SBM	Scroll bar control
STM	Static control
TB	Toolbar
TBM	Trackbar
TCM	Tab control
TTM	Tooltip control
TVM	Tree view control
UDM	Up-down control
WM	General window

The symbolic constants that identify system messages have values in the range 0 to WM_USER-1, so this range of values is reserved. An application can create messages for its own purposes and such messages can have identifiers with values in the range from WM_USER (that corresponds to the value 0x0400) to 0x7FFF.