keybd_event

The keybd_event function synthesizes a keystroke. The system can use such a synthesized keystroke to generate a WM_KEYUP or WM_KEYDOWN message. The keyboard driver's interrupt handler calls the keybd_event function.

Windows NT: This function has been superseded. Use SendInput instead.

VOID keybd_event(
  BYTE bVk,           // virtual-key code
  BYTE bScan,         // hardware scan code
  DWORD dwFlags,      // flags specifying various function options
  DWORD dwExtraInfo   // additional data associated with keystroke
);
 

Parameters

bVk

Specifies a virtual-key code. The code must be a value in the range 1 to 254.

bScan

Specifies a hardware scan code for the key.

dwFlags

A set of flag bits that specify various aspects of function operation. An application can use any combination of the following predefined constant values to set the flags.

Value	Meaning
KEYEVENTF_EXTENDEDKEY	If specified, the scan code was preceded by a prefix byte having the value 0xE0 (224).
KEYEVENTF_KEYUP	If specified, the key is being released. If not specified, the key is being depressed.

dwExtraInfo

Specifies an additional 32-bit value associated with the key stroke.

Return Values

This function has no return value.

Remarks

Although keybd_event passes an OEM-dependent hardware scan code to the system, applications should not use the scan code. The system converts scan codes to virtual-key codes internally and clears the up/down bit in the scan code before passing it to applications.

An application can simulate a press of the PRINTSCREEN key in order to obtain a screen snapshot and save it to the clipboard. To do this, call keybd_event with the bVk parameter set to VK_SNAPSHOT, and the bScan parameter set to 0 for a snapshot of the full screen or set bScan to 1 for a snapshot of the active window.

Windows CE: Windows CE supports an additional flag for the dwFlags parameter. Use the KEYEVENTF_SILENT flag to simulate a keystroke without making a clicking sound.

Windows CE does not support the KEYEVENTF_EXTENDEDKEY flag.

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.
  Import Library: Use user32.lib.

See Also

Keyboard Input Overview, Keyboard Input Functions, GetAsyncKeyState, GetKeyState, MapVirtualKey, SetKeyboardState