WM_APPCOMMAND message

Notifies a window that the user generated an application command event, for example, by clicking an application command button using the mouse or typing an application command key on the keyboard.

#define WM_APPCOMMAND                   0x0319

wParam

A handle to the window where the user clicked the button or pressed the key. This can be a child window of the window receiving the message. For more information about processing this message, see the Remarks section.

lParam

Use the following code to get the information contained in the lParam parameter.

cmd  = GET_APPCOMMAND_LPARAM(lParam);

uDevice = GET_DEVICE_LPARAM(lParam);

dwKeys = GET_KEYSTATE_LPARAM(lParam);

The application command is cmd, which can be one of the following values.

Expand table

Value	Meaning
APPCOMMAND_BASS_BOOST 20	Toggle the bass boost on and off.
APPCOMMAND_BASS_DOWN 19	Decrease the bass.
APPCOMMAND_BASS_UP 21	Increase the bass.
APPCOMMAND_BROWSER_BACKWARD 1	Navigate backward.
APPCOMMAND_BROWSER_FAVORITES 6	Open favorites.
APPCOMMAND_BROWSER_FORWARD 2	Navigate forward.
APPCOMMAND_BROWSER_HOME 7	Navigate home.
APPCOMMAND_BROWSER_REFRESH 3	Refresh page.
APPCOMMAND_BROWSER_SEARCH 5	Open search.
APPCOMMAND_BROWSER_STOP 4	Stop download.
APPCOMMAND_CLOSE 31	Close the window (not the application).
APPCOMMAND_COPY 36	Copy the selection.
APPCOMMAND_CORRECTION_LIST 45	Brings up the correction list when a word is incorrectly identified during speech input.
APPCOMMAND_CUT 37	Cut the selection.
APPCOMMAND_DICTATE_OR_COMMAND_CONTROL_TOGGLE 43	Toggles between two modes of speech input: dictation and command/control (giving commands to an application or accessing menus).
APPCOMMAND_FIND 28	Open the Find dialog.
APPCOMMAND_FORWARD_MAIL 40	Forward a mail message.
APPCOMMAND_HELP 27	Open the Help dialog.
APPCOMMAND_LAUNCH_APP1 17	Start App1.
APPCOMMAND_LAUNCH_APP2 18	Start App2.
APPCOMMAND_LAUNCH_MAIL 15	Open mail.
APPCOMMAND_LAUNCH_MEDIA_SELECT 16	Go to Media Select mode.
APPCOMMAND_MEDIA_CHANNEL_DOWN 52	Decrement the channel value, for example, for a TV or radio tuner.
APPCOMMAND_MEDIA_CHANNEL_UP 51	Increment the channel value, for example, for a TV or radio tuner.
APPCOMMAND_MEDIA_FAST_FORWARD 49	Increase the speed of stream playback. This can be implemented in many ways, for example, using a fixed speed or toggling through a series of increasing speeds.
APPCOMMAND_MEDIA_NEXTTRACK 11	Go to next track.
APPCOMMAND_MEDIA_PAUSE 47	Pause. If already paused, take no further action. This is a direct PAUSE command that has no state. If there are discrete Play and Pause buttons, applications should take action on this command as well as APPCOMMAND_MEDIA_PLAY_PAUSE.
APPCOMMAND_MEDIA_PLAY 46	Begin playing at the current position. If already paused, it will resume. This is a direct PLAY command that has no state. If there are discrete Play and Pause buttons, applications should take action on this command as well as APPCOMMAND_MEDIA_PLAY_PAUSE.
APPCOMMAND_MEDIA_PLAY_PAUSE 14	Play or pause playback. If there are discrete Play and Pause buttons, applications should take action on this command as well as APPCOMMAND_MEDIA_PLAY and APPCOMMAND_MEDIA_PAUSE.
APPCOMMAND_MEDIA_PREVIOUSTRACK 12	Go to previous track.
APPCOMMAND_MEDIA_RECORD 48	Begin recording the current stream.
APPCOMMAND_MEDIA_REWIND 50	Go backward in a stream at a higher rate of speed. This can be implemented in many ways, for example, using a fixed speed or toggling through a series of increasing speeds.
APPCOMMAND_MEDIA_STOP 13	Stop playback.
APPCOMMAND_MIC_ON_OFF_TOGGLE 44	Toggle the microphone.
APPCOMMAND_MICROPHONE_VOLUME_DOWN 25	Decrease microphone volume.
APPCOMMAND_MICROPHONE_VOLUME_MUTE 24	Mute the microphone.
APPCOMMAND_MICROPHONE_VOLUME_UP 26	Increase microphone volume.
APPCOMMAND_NEW 29	Create a new window.
APPCOMMAND_OPEN 30	Open a window.
APPCOMMAND_PASTE 38	Paste
APPCOMMAND_PRINT 33	Print current document.
APPCOMMAND_REDO 35	Redo last action.
APPCOMMAND_REPLY_TO_MAIL 39	Reply to a mail message.
APPCOMMAND_SAVE 32	Save current document.
APPCOMMAND_SEND_MAIL 41	Send a mail message.
APPCOMMAND_SPELL_CHECK 42	Initiate a spell check.
APPCOMMAND_TREBLE_DOWN 22	Decrease the treble.
APPCOMMAND_TREBLE_UP 23	Increase the treble.
APPCOMMAND_UNDO 34	Undo last action.
APPCOMMAND_VOLUME_DOWN 9	Lower the volume.
APPCOMMAND_VOLUME_MUTE 8	Mute the volume.
APPCOMMAND_VOLUME_UP 10	Raise the volume.

The uDevice component indicates the input device that generated the input event, and can be one of the following values.

Expand table

Value	Meaning
FAPPCOMMAND_KEY 0	User pressed a key.
FAPPCOMMAND_MOUSE 0x8000	User clicked a mouse button.
FAPPCOMMAND_OEM 0x1000	An unidentified hardware source generated the event. It could be a mouse or a keyboard event.

The dwKeys component indicates whether various virtual keys are down, and can be one or more of the following values.

Expand table

Value	Meaning
MK_CONTROL 0x0008	The CTRL key is down.
MK_LBUTTON 0x0001	The left mouse button is down.
MK_MBUTTON 0x0010	The middle mouse button is down.
MK_RBUTTON 0x0002	The right mouse button is down.
MK_SHIFT 0x0004	The SHIFT key is down.
MK_XBUTTON1 0x0020	The XBUTTON1 is down.
MK_XBUTTON2 0x0040	The XBUTTON2 is down.

If an application processes this message, it should return TRUE. For more information about processing the return value, see the Remarks section.

DefWindowProc generates the WM_APPCOMMAND message when it processes the WM_XBUTTONUP or WM_NCXBUTTONUP message, or when the user types an application command key.

If a child window does not process this message and instead calls DefWindowProc, DefWindowProc will send the message to its parent window. If a top level window does not process this message and instead calls DefWindowProc, DefWindowProc will call a shell hook with the hook code equal to HSHELL_APPCOMMAND.

To get the coordinates of the cursor if the message was generated by a mouse click, the application can call GetMessagePos. An application can test whether the message was generated by the mouse by checking whether lParam contains FAPPCOMMAND_MOUSE.

Unlike other windows messages, an application should return TRUE from this message if it processes it. Doing so will allow software that simulates this message on Windows systems earlier than Windows 2000 to determine whether the window procedure processed the message or called DefWindowProc to process it.

Reference

DefWindowProc

GET_APPCOMMAND_LPARAM

GET_DEVICE_LPARAM

GET_KEYSTATE_LPARAM

ShellProc

WM_XBUTTONUP

WM_NCXBUTTONUP

Conceptual

Mouse Input