WndProc Value and Description

Wm_null = 0x0000
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
Change the Enable state
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
Ask for a window to repaint itself
Wm_close = 0x0010
Send a signal when a window or application is about to close
Wm_queryendsession = 0x0011
When the user chooses the End dialog box or the program calls the ExitWindows function itself
Wm_quit = 0x0012
Used to end a program run or when a program calls the PostQuitMessage function
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 (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
Tell it whether the conversation is over
Wm_systemerror = 0x0017
Wm_showwindow = 0x0018
When the hidden or displayed window is sent this message to this window
Wm_activateapp = 0x001c
Send this message to the application which window is active and which is 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 in-progress state (operation)
Wm_setcursor = 0x0020
If the mouse causes the cursor to move through a window and the mouse input is not captured, a message is sent to a 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 clicks the title bar of this window, or when the window is activated, moves, changes the size
Wm_queuesync = 0x0023
This message is sent by a computer-based training program, via the Wh_journalpalyback hook program
Separating out user input messages
Wm_getminmaxinfo = 0x0024
This message is sent to the window when it is going to change size or position
Wm_painticon = 0x0026
Send to minimized window when its icon is going to be redrawn
Wm_iconerasebkgnd = 0x0027
This message is sent to a minimized window only if it's background must be redrawn before drawing the icon
Wm_nextdlgctl = 0x0028
Send this message to a dialog box program to change the focus position
Wm_spoolerstatus = 0x002a
This message is emitted whenever a print management queue increases or decreases a job
Wm_drawitem = 0x002b
Send when the visual appearance of the Button,combobox,listbox,menu changes
This message is given to the owner of these empty pieces
Wm_measureitem = 0x002c
When button, combo box, list box, List View control, or menu item is created
Send this message to the owner of the control
Wm_deleteitem = 0x002D
When the list box or combo box is destroyed or when certain items are deleted through lb_deletestring, lb_resetcontent, cb_deletestring, or cb_resetcontent messages
Wm_vkeytoitem = 0x002e
This message has a lbs_wantkeyboardinput style issued to its owner in response to the WM_KEYDOWN message
Wm_chartoitem = 0x002f
This message is sent by a lbs_wantkeyboardinput-style list box to his owner in response to the WM_CHAR message
Wm_setfont = 0x0030
The program sends this message when the text is drawn to get the color of the control to be used
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 can
Returns a handle to an icon or cursor that the system displays when the user drags and places the icon
Wm_compareitem = 0x0039
Send this message to determine the relative position of the newly added item in the ComboBox or ListBox
Wm_getobject = 0x003d
wm_compacting = 0x0041
Display memory is very low.
wm_windowposchanging = 0x0046
Call the SetWindowPos function or other window management function when sending this message to the size and position of the window that will be changed
wm_windowposchanged = 0x0047
Call the SetWindowPos function or other window management function when sending this message to the size and position of the window that has been changed
Wm_power = 0x0048 (for 16-bit Windows)
This message is sent when the system is about to enter a paused 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, the message is submitted to the program
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 platform site has been changed
Wm_tcard = 0x0052
Send this message to the application when the program has initialized the Windows Help routine
Wm_help = 0x0053
This message shows that the user pressed the F1, and if a menu is active, send this message to the menu associated with this window, otherwise
Sends this message to the currently active window if there is currently no focus.
wm_userchanged = 0x0054
When the user has logged in or exited to send this message to all windows, when the user log in or exit the system updates the user's specific
Set up information that the system sends this message as soon as the user updates the settings
Wm_notifyformat = 0x0055
Common controls, custom controls, and their parent window use this message to determine whether a control is using an ANSI or Unicode structure
In WM_NOTIFY messages, use this control to communicate with each other between a control and its parent control
Wm_contextmenu = 0x007b
This message is sent to this window when the user clicks the right button in a window
wm_stylechanging = 0x007c
This message is sent to the window when the call to the SetWindowLong function will change the style of one or more windows
wm_stylechanged = 0x007d
When you call the SetWindowLong function one or more window styles, send this message to that window
Wm_displaychange = 0x007e
Send this message to all windows when the resolution of the monitor changes
Wm_geticon = 0x007F
This message is sent to a window to return a handle to a large icon or small icon attached to a window
Wm_seticon = 0x0080
The program 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 the customer area of a window must be accounted for
Wm_nchittest = 0x0084//Occurs when the mouse is moved, pressed or released
Wm_ncpaint = 0x0085
The program sends this message to a window when it (the window) 's frame must be drawn
Wm_ncactivate = 0x0086
This message is sent to a window only if its non-client area needs to be changed to show whether it is active or inactive
Wm_getdlgcode = 0x0087
Send this message to a control that is associated with a dialog box program, widdows the control azimuth key and TAB key to make the input enter this control
By responding to Wm_getdlgcode messages, the application can treat him as a special input control and handle it
Wm_ncmousemove = 0x00a0
Send this message when the cursor moves within a window's non-client area to this window//non-client area: the title bar and window of the form
The Border body
Wm_nclbuttondown = 0x00A1
Submits this message when the cursor presses the left mouse button at the same time in the non-client area of a window
Wm_nclbuttonup = 0X00A2
This message is sent when the user releases the left mouse button while the cursor is in a window in non-client area 10
WM_NCLBUTTONDBLCLK = 0X00A3
This message is sent when the user double-clicks the left mouse button while the cursor is in a non-client area 10
Wm_ncrbuttondown = 0x00a4
This message is sent when the user presses the right mouse button while the cursor is in the non-client area of the window
Wm_ncrbuttonup = 0x00a5
This message is sent when the user releases the right mouse button while the cursor is in the non-client area of the window
WM_NCRBUTTONDBLCLK = 0x00a6
This message is sent when the user double-clicks the right mouse button while the cursor is in the non-client area 10
Wm_ncmbuttondown = 0x00a7
This message is sent when the user presses the middle mouse button while the cursor is in the non-client area of the window
Wm_ncmbuttonup = 0x00a8
This message is sent when the user releases the middle mouse button while the cursor is in the non-client area of the window
WM_NCMBUTTONDBLCLK = 0x00a9
This message is sent when the user double-clicks the middle mouse button while the cursor is in the non-client area of the window
Wm_keyfirst = 0x0100
Wm_keydown = 0x0100
Press a key
Wm_keyup = 0x0101
Release a key
WM_CHAR = 0x0102
Press a key and have issued WM_KEYDOWN, WM_KEYUP message
Wm_deadchar = 0x0103
Send this message to the window with focus when translating wm_keyup messages with the TranslateMessage function
Wm_syskeydown = 0x0104
Submits this message to the window that has focus when the user presses the ALT key while pressing another key
Wm_syskeyup = 0x0105
Submits this message to the window that has focus when the user releases a key while the ALT key is still pressed
Wm_syschar = 0x0106
When the Wm_syskeydown message is translated by the TranslateMessage function, the message is submitted to the window that has the focus
Wm_sysdeadchar = 0x0107
Send this message to the window with focus when the Wm_syskeydown message is translated by the TranslateMessage function
Wm_keylast = 0x0108
Wm_initdialog = 0x0110
Sends this message to a dialog box before it is displayed, typically using this message to initialize the control and perform other tasks
Wm_command = 0x0111
When a user selects a menu command item or when a control sends a message to its parent window, a shortcut key is translated
Wm_syscommand = 0x0112
The window receives this message when the user chooses a command on the Window menu or when the user chooses to maximize or minimize
Wm_timer = 0x0113//Timer event occurred
Wm_hscroll = 0x0114
When a window standard horizontal scrollbar produces a scrolling event, this message is sent to that window and also to the control that owns it
Wm_vscroll = 0x0115
When a window standard vertical scrollbar produces a scrolling event, this message is sent to that window, which is also sent to the control that owns it wm_initmenu = 0x0116
This message is sent when a menu is about to be activated, it occurs on an item in the user's menu bar, or a menu key is pressed, which allows
The program changes 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 the program to change the menu before it is displayed, rather than
Change All
Wm_menuselect = 0x011f
Send this message to the owner of the menu (typically a window) when the user selects a menu item
Wm_menuchar = 0x0120
When the menu has been activated the user presses a key (unlike the accelerator key) and sends this message to the owner of the menu
Wm_enteridle = 0x0121
Sends this message to its owner when a modal dialog box or menu enters an empty state, and a modal dialog box or menu enters an empty state, which waits in the queue without a message after processing one or several previous messages
Wm_menurbuttonup = 0x0122
Wm_menudrag = 0x0123
Wm_menugetobject = 0x0124
Wm_uninitmenupopup = 0x0125
Wm_menucommand = 0x0126
Wm_changeuistate = 0x0127
Wm_updateuistate = 0x0128
Wm_queryuistate = 0x0129
Wm_ctlcolormsgbox = 0x0132
This message is sent to the owner window of the message box before Windows draws the message box, and by responding to this message, the owner window can
Sets the text and background color of a message box by using the handle of a given related display device
Wm_ctlcoloredit = 0x0133
When an edit control is about to be drawn when this message is sent to its parent window by responding to this message, the owner window can
Sets the text and background color of the edit box by using the handle of the given related display device
Wm_ctlcolorlistbox = 0x0134
When a ListBox control is going to be drawn before sending this message to its parent window by responding to this message, the owner window can
Sets the text and background color of a list box by using the handle of a given related display device
WM_CTLCOLORBTN = 0x0135
When a button control is about to be drawn when this message is sent to its parent window by responding to this message, the owner window can
Sets the text and background color of the button by using the handle of the given related display device
Wm_ctlcolordlg = 0x0136
When a dialog box control is going to be drawn before sending this message to its parent window by responding to this message, the owner window can
Sets the text background color of a dialog box by using the handle of a given related display device
Wm_ctlcolorscrollbar= 0x0137
When a scrollbar control is about to be drawn when this message is sent to its parent window by responding to this message, the owner window can
Sets the background color of the scroll bar by using the handle of the given related display device
Wm_ctlcolorstatic = 0x0138
When a static control is about to be drawn when this message is sent to its parent window by responding to this message, the owner window can
Sets the text and background color of a static control by using the handle of a given related display device
Wm_mousefirst = 0x0200
Wm_mousemove = 0x0200
Move mouse
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 when the mouse wheel is rotated a control that currently has focus
Wm_mouselast = 0x020a
Wm_parentnotify = 0x0210
When the MDI child window is created or destroyed, or the user presses the mouse button while the cursor is over the child window, the message is sent to its parent window
Wm_entermenuloop = 0x0211
Send this message to notify the application of the main window that has entered the menu loop mode
Wm_exitmenuloop = 0x0212
Send this message to notify the application of the main window that has exited the menu loop mode
Wm_nextmenu = 0x0213
wm_sizing = 532
When a user is resizing a window, sending this message to a window through this message application can monitor the window size and position
You can also modify their
wm_capturechanged = 533
Send this message to the window when it loses the captured mouse
wm_moving = 534
When the user sends this message while the window is being moved, the message application can monitor the window size and position
You can also modify their
Wm_powerbroadcast = 536
This message is sent to the application to notify it about power management events
Wm_devicechange = 537
Send this message to the application or device driver when the device's hardware configuration changes
Wm_ime_startcomposition = 0x010d
Wm_ime_endcomposition = 0x010e
Wm_ime_composition = 0x010f
Wm_ime_keylast = 0x010f
Wm_ime_setcontext = 0x0281
Wm_ime_notify = 0x0282
Wm_ime_control = 0x0283
Wm_ime_compositionfull = 0x0284
Wm_ime_select = 0x0285
Wm_ime_char = 0x0286
Wm_ime_request = 0x0288
Wm_ime_keydown = 0x0290
Wm_ime_keyup = 0x0291
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 a multi-document customer window to notify the client window to activate another MDI child window when the customer window receives
After this message, it emits a wm_mdiactive message to the MDI child window (not activated) to activate it
Wm_mdirestore = 0x0223
The program sends this message to the MDI client window to restore the child window to its original size from the maximum minimized
Wm_mdinext = 0x0224
The program sends this message to the MDI client window to activate the next or previous window
Wm_mdimaximize = 0x0225
The program sends this message to the MDI client window to maximize an MDI child window
Wm_mditile = 0x0226
The program sends this message to the MDI client window to re-arrange all MDI child windows in a tiled manner
Wm_mdicascade = 0x0227
The program sends this message to the MDI client window to rearrange all MDI child windows in a cascade manner
Wm_mdiiconarrange = 0x0228
The program sends this message to the MDI client window to rearrange all the minimized MDI child windows
Wm_mdigetactive = 0x0229
The program sends this message to the MDI client window to find the handle to the active child window
Wm_mdisetmenu = 0x0230
The program sends this message to the MDI client window using the MDI menu instead of the child window's menu
Wm_entersizemove = 0x0231
Wm_exitsizemove = 0x0232
Wm_dropfiles = 0x0233
Wm_mdirefreshmenu = 0x0234
Wm_mousehover = 0X02A1
Wm_mouseleave = 0x02a3
Wm_cut = 0x0300
The program sends this message to an edit box or ComboBox to delete the currently selected text
Wm_copy = 0x0301
The program sends this message to an edit box or ComboBox to copy the currently selected text to the Clipboard
Wm_paste = 0x0302
The program sends this message to the Editcontrol or ComboBox to get data from the Clipboard
Wm_clear = 0x0303
The program sends this message to the Editcontrol or ComboBox to clear the currently selected content
Wm_undo = 0x0304
The program sends this message to the Editcontrol or ComboBox to undo the last action
Wm_renderformat = 0x0305

Wm_renderallformats = 0x0306
Wm_destroyclipboard = 0x0307
Send this message to the owner of the Clipboard when the Enptyclipboard function is called
Wm_drawclipboard = 0x0308
This message is sent to the Clipboard in the first window of the watch chain when the contents of the Clipboard change. It allows the Clipboard to be viewed with a window to
Show new contents of clipboard
Wm_paintclipboard = 0x0309
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
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, this message is sent to the Clipboard owner through the Clipboard Observation window
Wm_askcbformatname = 0x030c
Send this message through the Clipboard Watch window to the owner of the Clipboard to request a Cf_ownerdisplay-formatted clipboard name
Wm_changecbchain = 0x030d
Send this message to the first window of the Clipboard watch chain when a window is removed from the Clipboard watch chain
Wm_hscrollclipboard = 0x030e
This message is sent to the owner of the Clipboard through a Clipboard observation window it occurs when the Clipboard contains data in cfownerdispaly format and there is an event on the horizontal scroll bar of the Clipboard view the owner should scroll the clipboard image and update the ScrollBar's value
Wm_querynewpalette = 0x030f
This message is sent to the window that will receive the focus, which gives the window a chance to implement his logical palette when it receives the focus
wm_paletteischanging= 0x0310
Send this message to notify all applications when an application is about to implement its logical palette
wm_palettechanged = 0x0311
This message sends this message to all top-level and overlapping windows after it implements its logical palette in a window that has the focus.
To change the system palette
Wm_hotkey = 0x0312
This message is submitted when the user presses a hotkey registered by the RegisterHotKey function
Wm_print = 791
The application sends this message only when Windows or another application makes a request to draw part of an application
Wm_printclient = 792
Wm_handheldfirst = 856
Wm_handheldlast = 863
Wm_penwinfirst = 0x0380
Wm_penwinlast = 0x038f
Wm_coalesce_first = 0x0390
Wm_coalesce_last = 0x039f
Wm_dde_first = 0x03e0
Wm_dde_initiate = wm_dde_first + 0
A DDE client submits this message to start a session with the server program in response to the specified program and subject name
Wm_dde_terminate = Wm_dde_first + 1
A DDE application (either client or server) submits this message to terminate a session
Wm_dde_advise = Wm_dde_first + 2
A DDE client submits this message to a DDE service program to request that the server update it whenever the data item changes
Wm_dde_unadvise = Wm_dde_first + 3
A DDE client notifies a DDE service through this message that the item is not updated by the specified item or a special Clipboard format
Wm_dde_ack = Wm_dde_first + 4
This message informs a DDE (Dynamic data exchange) program that it has received and is processing Wm_dde_poke, Wm_dde_execute, Wm_dde_data, Wm_dde_advise, wm_dde_unadvise, or Wm_dde_ Initiat message
Wm_dde_data = Wm_dde_first + 5
A DDE service program submits this message to a DDE client to pass a data item to the customer or to notify the customer of an available data item
Wm_dde_request = Wm_dde_first + 6
A DDE client submits this message to a DDE service program to request a value for a data item
Wm_dde_poke = Wm_dde_first + 7
A DDE client submits this message to a DDE service program, and the customer uses this message to request that the server receive an unsolicited data item from the server by replying to the Wm_dde_ack message to indicate whether it receives this data item
Wm_dde_execute = Wm_dde_first + 8
A DDE client submits this message to a DDE service program to send a string to the server so that it is processed like a serial command, and the server responds by submitting a wm_dde_ack message.
Wm_dde_last = Wm_dde_first + 8
Wm_app = 0x8000
Wm_user = 0x0400
This message can help the application customize the private message
/////////////////////////////////////////////////////////////////////
Notification messages (Notification message) refer to a message that a child control within a window has something that needs to be
The parent window is known. Notification messages apply only to standard window controls such as buttons, list boxes, combo boxes, edit boxes, and Windows 95 public
Common controls such as tree view, List view, and so on. For example, clicking or double-clicking a control, selecting part of the text in the control, manipulating the control's
The scroll bar generates a notification message.
Press Twist
B N _ C L I C K E D//user clicked the button
b N _ D I S A B L E//button is forbidden
b N _ D O U B l e c l I C K e d//user double-click the button
B N _ H i L i T E//User Highlight button
B N _ PA I N T button should repaint
B N _ U n H i L T e highlight should be removed
Combo box
C B N _ C L O S E U p combo box list box is closed
C B N _ D b l C L k user double-clicked on a string
C B N _ d R O P D o W N combo box list box is pulled out
C B N _ E D I T C H A N G E User modified the text in the edit box
C B N _ e d I T U P D at E the text in the edit box is about to be updated
C B N _ e R r S PA c e combo box low Memory
C B N _ K I l l F O C U s combo box loses input focus
C B N _ S e L C H a N G E Select an item in the combo box
C B N _ S e L e n D c A N C E L User selection should be canceled
C B N _ S e L e N D O K user's choice is legal
C B N _ s E T F O C U S combo box Get input focus
edit box
E n _ C H A N G E The text in the edit box has been updated
E N _ e R r S PA C e edit box Not enough memory
E N _ H S C R O l l user clicked the horizontal scroll bar
E N _ K I l F O C U s edit box is losing input focus
E N _ M A x t e x t inserted content truncated
E N _ S e T F O C U S edit box Get input focus
E N _ U P D at E The text in the edit box will be updated
E N _ V S C R O l l the user clicked on the vertical scroll bar message meaning
list box
L B N _ D b l C L k user double-clicked on an item
L B N _ e R r S PA C e list box not enough memory
L B N _ K I l l F O C U s list box is losing input focus
L B N _ S E l C A n C E L selection canceled
L B N _ S e L C H A N G E Select another
L B N _ s E T F O C U S list box get input focus

WndProc Value and Description