WM_COMMAND

The WM_COMMAND message is sent when the user selects a command item from a menu, when a control sends a notification message to its parent window, or when an accelerator keystroke is translated.

WM_COMMAND 
wNotifyCode = HIWORD(wParam); // notification code 
wID = LOWORD(wParam);         // item, control, or accelerator identifier 
hwndCtl = (HWND) lParam;      // handle of control 
 

Parameters

wNotifyCode

Value of the high-order word of wParam. Specifies the notification code if the message is from a control. If the message is from an accelerator, this parameter is 1. If the message is from a menu, this parameter is 0.

wID

Value of the low-order word of wParam. Specifies the identifier of the menu item, control, or accelerator.

hwndCtl

Value of lParam. Handle to the control sending the message if the message is from a control. Otherwise, this parameter is NULL.

Return Values

If an application processes this message, it should return zero.

Remarks

Accelerator keystrokes that select items from the window menu are translated into WM_SYSCOMMAND messages.

If an accelerator keystroke occurs that corresponds to a menu item when the window that owns the menu is minimized, no WM_COMMAND message is sent. However, if an accelerator keystroke occurs that does not match any of the items in the window's menu or in the window menu, a WM_COMMAND message is sent, even if the window is minimized.

If an application enables a menu separator, the system sends a WM_COMMAND message with the low-word of the wParam parameter set to zero when the user selects the separator.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.

See Also

Edit Controls Overview, Edit Control Messages, WM_SYSCOMMAND