Common messages and meanings of Windows

Message Range	Description
0 ~ wm_user–1	System messages
Wm_user ~ 0x7FFF	Custom window class integer messages
Wm_app ~ 0xBFFF	Application Custom Messages
0xc000 ~ 0xFFFF	Application string Messages
> 0xFFFF	Apply retention for future systems

Message name	Value	Meaning
Wm_null	0x0000	Empty message, this message will be ignored by the receiving window
Wm_create	0x0001	Application creates a window
Wm_destroy	0x0002	A window is destroyed
Wm_move	0x0003	Move a window
Wm_size	0x0005	Change the size of a window
Wm_activate	0x0006	A window is activated or inactive
Wm_setfocus	0x0007	After gaining focus
Wm_killfocus	0x0008	Lose focus
Wm_enable	0x000A	Generated when the application Enable state changes
Wm_setredraw	0x000b	Sets whether the window can be redrawn
Wm_settext	0x000c	The application sends this message to set the text of a window
Wm_gettext	0x000d	The application sends this message to copy the corresponding window's text to the buffer
Wm_gettextlength	0x000e	Gets the length of the text associated with a window (does not contain null characters)
Wm_paint	0x000f	require a window to redraw itself
Wm_close	0x0010	Send a signal when a window or application is about to close
Wm_queryendsession	0x0011	The user selects the End dialog box or the application calls the ExitWindows function itself
Wm_quit	0x0012	Used to end a program run or an application calling the PostQuitMessage function to produce this message
Wm_queryopen	0x0013	Sends this message to an icon when the user window restores the previous size position
Wm_erasebkgnd	0x0014	When the window background must be erased (for example, when the window changes size)
Wm_syscolorchange	0x0015	Send this message to all top-level windows when the system color changes
Wm_endsession	0x0016	When the system process issues a WM_QUERYENDSESSION message, this message is sent to the application
Wm_showwindow	0x0018	When the hidden or displayed window is sent this message to this window
Wm_activateapp	0x001c	When a window will be activated, the window will be activated and the current activity (about to lose the activation) window will receive this message, sending this message to the application which window is active, which is the inactive
Wm_fontchange	0x001d	This message is sent to all top-level windows when the system's font repository changes
Wm_timechange	0x001e	Send this message to all top-level windows when the system's time changes
Wm_cancelmode	0x001f	Send this message to cancel an operation that is in progress
Wm_setcursor	0x0020	If the mouse causes the cursor to move through a window and the mouse input is not captured, send a message to the window
Wm_mouseactivate	0x0021	When the cursor is in a non-activated window and the user is pressing a key on the mouse to send this message to the current window
Wm_childactivate	0x0022	Send this message to the MDI child window when the user taps the title bar of this window, or when the window is activated, moved, resized
Wm_queuesync	0x0023	This message is sent by a computer-based training program that separates the user input message from the Wh_journalpalyback Hook program
Wm_getminmaxinfo	0x0024	When the window is going to change size or position, send this message to the window
Wm_painticon	0x0026	When the window icon is going to be redrawn, send this message to the window
Wm_iconerasebkgnd	0x0027	This message is sent to the window when the icon background must be redrawn before the icon in a minimized window is redrawn
Wm_nextdlgctl	0x0028	Send this message to a dialog box program to change the focus location
Wm_spoolerstatus	0x002a	This message is emitted when a print management queue increases or decreases a job
Wm_drawitem	0x002b	When the appearance of the Button,combobox,listbox,menu control changes, this message is sent to the owner of these controls
Wm_measureitem	0x002c	When the Button,combobox,list box,listview,menu item is created, this message is sent to the owner of the control
Wm_deleteitem	0x002D	When a ListBox or ComboBox is destroyed or when certain items are deleted by sending lb_deletestring, Lb_resetcontent, cb_deletestring, cb_resetcontent messages, Send this message to the owner of the control
Wm_vkeytoitem	0x002e	A ListBox control with a lbs_wantkeyboardinput style sends this message to its owner in response to the WM_KEYDOWN message
Wm_chartoitem	0x002f	A ListBox control with a lbs_wantkeyboardinput style sends this message to its owner in response to the WM_CHAR message
Wm_setfont	0x0030	When the application draws the control, this message is sent to get the text in the control in which font is drawn
Wm_getfont	0x0031	The application sends this message to get the font of the current control drawing text
Wm_sethotkey	0x0032	The application sends this message to have a window associated with a hotkey
Wm_gethotkey	0x0033	The application sends this message to determine if a hot key is associated with a window
Wm_querydragicon	0x0037	This message is sent to the minimized window, and when the window is about to be dragged and the icon is not defined in its class, the application returns an icon or a handle to the cursor that the system displays when the user drags and puts the icon
Wm_compareitem	0x0039	Send this message to determine the relative position of the newly added item in the ComboBox or ListBox
Wm_compacting	0x0041	Display memory is very low.
Wm_windowposchanging	0x0046	When the SetWindowPos function is called to change the size and position of the window, send this message to the window
Wm_power	0x0048	This message is sent to all processes when the system will go into a pending state
Wm_copydata	0x004a	This message is sent when an application passes data to another application
Wm_canceljournal	0x004b	When a user cancels the program Log activation state, this message is sent to the application
Wm_notify	0x004e	Sends this message to its parent window when an event for a control has already occurred or if the control needs to get some information
Wm_inputlangchangerequest	0x0050	When the user chooses an input language, or the hotkey of the input language changes
Wm_inputlangchange	0x0051	Send this message to the affected top-level window when the application input language changes
Wm_tcard	0x0052	Send this message to the application when the application has initialized the Windows help routine
Wm_help	0x0053	When the user presses F1, if a menu is active, send this message to the menu associated with the window, otherwise it will be sent to the focus window, and if there is no focus, send the message to the currently active window
Wm_userchanged	0x0054	When the user has logged in or exited to send this message to all windows, when the user logs on or exits the system updates the user's specific settings information, the system sends this message as soon as the user updates the settings
Wm_notifyformat	0x0055	This message is used by common controls and their parent window to determine whether the structure is in ANSI or UNICODE form in the WM_NOTIFY message, which enables the control to communicate with its parent control
Wm_contextmenu	0x007b	When the user clicks the right button in a window, this message is sent to the window
Wm_stylechanging	0x007c	When you are about to invoke one or more styles of the SetWindowLong function window, send this message to the window
Wm_stylechanged	0x007d	When the call SetWindowLong function changes one or more styles of the window, send this message to the window
Wm_displaychange	0x007e	Send this message to all windows when the resolution of the monitor changes
Wm_geticon	0x007F	Send this message to a window that returns a handle to a large icon or small icon associated with a window
Wm_seticon	0x0080	The application sends this message to have a new large icon or small icon associated with a window
Wm_nccreate	0x0081	When a window is first created, this message is sent before the WM_CREATE message is sent
Wm_ncdestroy	0x0082	This message notifies a window that the non-client area is being destroyed
Wm_nccalcsize	0x0083	This message is sent when calculating the client area size and location of a window
Wm_nchittest	0x0084	Generate this message when you move the mouse, press and hold or release the mouse
Wm_ncpaint	0x0085	When a window's frame must be drawn, the application sends this message to the window
Wm_ncactivate	0x0086	This message is sent to a window by changing its non-client area to indicate whether the window is active or inactive
Wm_ncmousemove	0x00a0	This message is sent to the window when the cursor moves within the window's non-client area (window title bar and border)
Wm_nclbuttondown	0x00A1	This message is sent when the cursor is in the non-client area of the window and the left mouse button is pressed
Wm_nclbuttonup	0x00a2	This message is sent when the cursor is in the non-client area of the window and the left mouse button is released
Wm_nclbuttondblclk	0x00a3	This message is sent when the cursor is in the non-client area of the window and the left mouse button is double-clicked
Wm_ncrbuttondown	0x00a4	This message is sent when the cursor is in the non-client area of the window and the right mouse button is pressed
Wm_ncrbuttonup	0x00a5	This message is sent when the cursor is in the non-client area of the window and the right mouse button is released
Wm_ncrbuttondblclk	0x00a6	This message is sent when the cursor is in the non-client area of the window and the right mouse button is double-clicked
Wm_ncmbuttondown	0x00a7	This message is sent when the cursor is in the non-client area of the window and the middle mouse button is pressed
Wm_ncmbuttonup	0x00a8	This message is sent when the cursor is in the non-client area of the window and releases the middle mouse button
Wm_ncmbuttondblcl	0x00a9	This message is sent when the cursor is in the non-client area of the window and the middle mouse button is double-clicked
Wm_keydown	0x0100	Press a non-system key (the "ALT" key is not pressed when the key is pressed)
Wm_keyup	0x0101	Release a non-system key
Wm_char	0x0102	Press a key to send this message when TranslateMessage forwards Wm_keydown
Wm_deadchar	0x0103	Release a key, send this message when TranslateMessage forwards Wm_keyup
Wm_syskeydown	0x0104	Send this message to a window that has keyboard focus when you hold down the ALT key while pressing another key
Wm_syskeyup	0x0105	Send this message to a window that has keyboard focus when releasing a key while holding down the ALT key
Wm_syschar	0x0106	Send this message to a window that has keyboard focus when the TranslateMessage function forwards Wm_syskeydown
Wm_sysdeadchar	0x0107	Send this message to a window that has keyboard focus when the TranslateMessage function forwards Wm_syskeyup
Wm_initdialog	0x0110	Send this message dialog box before it is displayed, typically using this message to initialize the control and perform other tasks
Wm_command	0x0111	This message is generated when you select a Window menu item or a control to send a message to its parent window or to press a shortcut key
Wm_syscommand	0x0112	When you select a Window menu item or select Maximize or minimize, this message is sent to the window
Wm_timer	0x0113	A timer event has occurred
Wm_hscroll	0x0114	This message is sent to the owner of the window and scroll bar when the window horizontal scrollbar produces a scrolling event
Wm_vscroll	0x0115	This message is sent to the owner of the window and scroll bar when the window vertical scrollbar produces a scrolling event
Wm_initmenu	0x0116	This message is sent when a menu is about to be activated, it occurs when a menu item is pressed, or when a menu shortcut is pressed, which allows the program to change the menu before it is displayed
Wm_initmenupopup	0x0117	This message is sent when a drop-down menu or submenu is about to be activated, allowing it to be displayed before the menu is modified without having to change the entire menu
Wm_menuselect	0x011f	Send this message to the owner of the menu when a menu item is selected (typically a window)
Wm_menuchar	0x0120	When the menu is activated and the user presses a key (non-accelerator), the message is sent to the owner of the menu
Wm_enteridle	0x0121	Sends this message to its owner when a modal dialog box or menu enters an idle state, which means that the message queue is empty after one or several previous messages have been processed
Wm_menurbuttonup	0x0122	When the cursor is over a menu item, release the right mouse button to generate this message
Wm_menudrag	0x0123	When you drag a menu item, this message is sent to the owner of the drag-and-drop menu
Wm_menugetobject	0x0124	Send this message to the owner of the drop-down menu when the cursor moves into the menu item or moves from the center of the menu item to the top or bottom of the item
Wm_uninitmenupopup	0x0125	This message is generated when the drop-down menu or submenu is destroyed
Wm_menucommand	0x0126	This message is generated when the user selects a menu item
Wm_changeuistate	0x0127	The application sends this message indicating that the user interface (UI) state should be changed
Wm_updateuistate	0x0128	The application sends this message to change the user interface (UI) state of the specified window and its child windows
Wm_queryuistate	0x0129	The application sends this message to get the user interface (UI) state of a window
Wm_ctlcolormsgbox	0x0132	Sends this message to its parent window before the message box is drawn, and in response to this message, the parent window can set the text and background color of the message box by using the handle of the given related display device
Wm_ctlcoloredit	0x0133	Sends this message to its parent window before drawing the edit control, which can be used to set the text and background color of the edit box
Wm_ctlcolorlistbox	0x0134	Sends this message to its parent window before drawing the ListBox control, which can be used to set the text and background color of the edit box
Wm_ctlcolorbtn	0x0135	Sends this message to its parent window before drawing the button control, which can be used to set the text and background color of the edit box
Wm_ctlcolordlg	0x0136	Sends this message to its parent window before drawing the dialog box, which can be used to set the text and background color of the edit box
Wm_ctlcolorscrollbar	0x0137	Sends this message to its parent window before drawing the scrollbar control, which you can use to set the text and background color of the scroll bar control
Wm_ctlcolorstatic	0x0138	Sends this message to its parent window before drawing a static control, which can be used to set the text and background color of a static control
Wm_mousemove	0x0200	Mouse movement
Wm_lbuttondown	0x0201	Press the left mouse button
Wm_lbuttonup	0x0202	Release left mouse button
Wm_lbuttondblclk	0x0203	Double click left mouse button
Wm_rbuttondown	0x0204	Press the right mouse button
Wm_rbuttonup	0x0205	Release the right mouse button
Wm_rbuttondblclk	0x0206	Double-click the right mouse button
Wm_mbuttondown	0x0207	Press the middle mouse button
Wm_mbuttonup	0x0208	Release middle mouse button
Wm_mbuttondblclk	0x0209	Double-click the middle mouse button
WM_MouseWheel	0x020a	Sends this message to the currently focused window when the mouse wheel is rotated
Wm_parentnotify	0x0210	When the MDI child window is created or destroyed, or when the cursor is over a child window and the user presses the mouse button, the message is sent to its parent window
Wm_entermenuloop	0x0211	Send this message to notify the application that the main window process has entered the menu mode loop
Wm_exitmenuloop	0x0212	Send this message to notify the application that the main window process has exited the menu mode loop
Wm_sizing	0x0214	Adjust window Large hours send this message to the window through which the application can monitor or modify the window size and position
Wm_capturechanged	0x0215	When the window is set to not capture mouse events, this message is sent to the window
Wm_moving	0x0216	When you move a window, this message is sent to the window through which the application can monitor or modify the window size and position
Wm_powerbroadcast	0x0218	Send this message to the application to notify it about power management events
Wm_devicechange	0x0219	Send this message to the application or device driver when the device's hardware configuration changes
Wm_mdicreate	0x0220	The application sends this message to a multi-document client window to create an MDI child window
Wm_mdidestroy	0x0221	The application sends this message to a multi-document client window to close an MDI child window
Wm_mdiactivate	0x0222	The application sends this message to the multi-document Customer window to notify the client window to activate another MDI child window, and when the client window receives this message, it issues a wm_mdiactive message to the MDI child window (not activated) to activate it
Wm_mdirestore	0x0223	The application sends this message to the MDI client window to notify the child window to revert to its original size
Wm_mdinext	0x0224	The application sends this message to the MDI client window to activate the next or previous window
Wm_mdimaximize	0x0225	The application sends this message to the MDI client window to maximize an MDI child window
Wm_mditile	0x0226	The application sends this message to the MDI client window to re-arrange all MDI child windows in a tiled manner
Wm_mdicascade	0x0227	The application sends this message to the MDI client window to cascade all MDI child windows
Wm_mdiiconarrange	0x0228	The application sends this message to the MDI client window to rearrange all the minimized MDI child windows
Wm_mdigetactive	0x0229	The application sends this message to the MDI client window to find the handle to the active child window
Wm_mdisetmenu	0x0230	The application sends this message to the MDI client window using the MDI menu instead of the child window's menu
Wm_entersizemove	0x0231	This message is sent to the window when the window enters the move or changes the size mode loop
Wm_exitsizemove	0x0232	This message is sent to the window when the window exits the move or changes the size mode loop
Wm_dropfiles	0x0233	This message is generated when a user drags a file in the application window
Wm_mdirefreshmenu	0x0234	The application sends this message to the MDI client window to refresh the Window menu
Wm_mousehover	0x02a1	When the cursor hovers over the window client area beyond the time specified by the TrackMouseEvent function, this message is sent to the window
Wm_mouseleave	0x02a3	This message is sent to the window when the cursor leaves the window client area longer than the time specified by the TrackMouseEvent function
Wm_cut	0x0300	The application sends this message to an edit box or ComboBox to delete the currently selected text
Wm_copy	0x0301	The application sends this message to an edit box or ComboBox to copy the currently selected text to the Clipboard
Wm_paste	0x0302	The application sends this message to an edit box or ComboBox to get the data from the Clipboard
Wm_clear	0x0303	The application sends this message to an edit box or ComboBox to clear the currently selected content
Wm_undo	0x0304	The application sends this message to an edit box or ComboBox to undo the last action
Wm_destroyclipboard	0x0307	When the EmptyClipboard function is called to empty the Clipboard, this message is sent to the clipboard owner
Wm_drawclipboard	0x0308	When the contents of the Clipboard are changed, this message is sent to the first window in the Clipboard Watch chain, which allows the Clipboard viewing window to display new contents of the Clipboard
Wm_paintclipboard	0x0309	This message is sent to the Clipboard owner when the Clipboard contains data in Cf_ownerdiplay format and the client area of the Clipboard Watch window needs to be redrawn
Wm_vscrollclipboard	0x030a	When the Clipboard contains Cf_ownerdiplay formatted data and the Clipboard Watch window has a vertical scrollbar event, the Clipboard Watch window sends this message to the Clipboard owner
Wm_sizeclipboard	0x030b	When the Clipboard contains data in cf_ownerdiplay format and the size of the client area of the Clipboard Watch window has changed, the Clipboard Watch window sends this message to the owner of the Clipboard
Wm_askcbformatname	0x030c	Clipboard Watch Window sends this message to the Clipboard owner to get the name of the Cf_ownerdisplay Clipboard format
Wm_changecbchain	0x030d	Send this message to the first window in the Clipboard watch chain when a window is removed from the Clipboard watch chain
Wm_hscrollclipboard	0x030e	The Clipboard Watch window sends this message to the Clipboard owner when the Clipboard contains Cf_ownerdiplay formatted data and the Clipboard Watch window has a horizontal scrollbar event
Wm_querynewpalette	0x030f	Send this message to the window that will get the keyboard focus, which gives the window a chance to implement its logical palette while gaining focus
Wm_paletteischanging	0x0310	The application will implement its logical palette when sending this message to notify all applications
Wm_palettechanged	0x0311	The window that gets the focus implements its logical palette after sending this message to all top-level and overlapping windows to change the system palette
Wm_hotkey	0x0312	This message is generated when the user presses a hotkey registered by the RegisterHotKey function
Wm_print	0x0317	The application sends this message to the window, requiring the window to draw itself in the specified device environment, typically the printer device environment
Wm_printclient	0x0318	The application sends this message to the window, requiring the window to draw windows in the specified device Environment client area, typically the printer device environment
Wm_app	0x8000	Help users customize messages, custom messages can be wm_app+x,x as positive integers
Wm_user	0x0400	Help users customize messages, custom messages can be wm_user+x,x as positive integers