keybd_event function (Windows)

Switch View :

ScriptFree

keybd_event function

Applies to: desktop apps only

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.

Note This function has been superseded. Use SendInput instead.

Syntax

VOID WINAPI keybd_event(
  __in  BYTE bVk,
  __in  BYTE bScan,
  __in  DWORD dwFlags,
  __in  ULONG_PTR dwExtraInfo
);

Parameters

bVk [in]

Type: BYTE

A virtual-key code. The code must be a value in the range 1 to 254. For a complete list, see Virtual Key Codes.

bScan [in]

Type: BYTE

A hardware scan code for the key.

dwFlags [in]

Type: DWORD

Controls various aspects of function operation. This parameter can be one or more of the following values.

Value	Meaning
KEYEVENTF_EXTENDEDKEY 0x0001	If specified, the scan code was preceded by a prefix byte having the value 0xE0 (224).
KEYEVENTF_KEYUP 0x0002	If specified, the key is being released. If not specified, the key is being depressed.

dwExtraInfo [in]

Type: ULONG_PTR

An additional value associated with the key stroke.

Return value

This function does not return a value.

Remarks

An application can simulate a press of the PRINTSCRN 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.

Examples

The following sample program toggles the NUM LOCK light by using keybd_event with a virtual key of VK_NUMLOCK. It takes a Boolean value that indicates whether the light should be turned off (FALSE) or on (TRUE). The same technique can be used for the CAPS LOCK key (VK_CAPITAL) and the SCROLL LOCK key (VK_SCROLL).



   #include <windows.h>

   void SetNumLock( BOOL bState )
   {
      BYTE keyState[256];

      GetKeyboardState((LPBYTE)&keyState);
      if( (bState && !(keyState[VK_NUMLOCK] & 1)) ||
          (!bState && (keyState[VK_NUMLOCK] & 1)) )
      {
      // Simulate a key press
         keybd_event( VK_NUMLOCK,
                      0x45,
                      KEYEVENTF_EXTENDEDKEY | 0,
                      0 );

      // Simulate a key release
         keybd_event( VK_NUMLOCK,
                      0x45,
                      KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,
                      0);
      }
   }

   void main()
   {
      SetNumLock( TRUE );
   }

Requirements

Minimum supported client	Windows 2000 Professional
Minimum supported server	Windows 2000 Server
Header	Winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll

[tfl - 24 06 10] Hi - and thanks for your post. You should post questions like this to the MSDN Forums at http://forums.microsoft.com/msdn or the MSDN Newsgroups at http://www.microsoft.com/communities/newsgroups/en-us/. You are much more likely get a quicker response using the forums than through the Community Content. For specific help about:
.NET Framework : http://groups.google.com/groups/dir?sel=usenet%3Dmicrosoft.public.dotnet.framework
PowerShell     : http://groups.google.com/group/microsoft.public.windows.powershell/topics?pli=1
SQL Server     : http://groups.google.com/groups/dir?sel=usenet%3Dmicrosoft.public.sqlserver%2C&
Visual Studio  : http://groups.google.com/groups/dir?sel=usenet%3Dmicrosoft.public.vstudio%2C&
Windows        : http://groups.google.com/groups/dir?sel=usenet%3Dmicrosoft.public.windows%2C&
All Public     : http://groups.google.com/groups/dir?sel=usenet%3Dmicrosoft.public%2C&

dornif

C# syntax

[DllImport("user32.dll", EntryPoint="keybd_event", CharSet=CharSet.Auto, ExactSpelling=true)]
public static extern void keybd_event(byte vk, byte scan, int flags, int extrainfo);

dmex

vb.net syntax

<DllImport("user32.dll", EntryPoint:="keybd_event", CharSet:=CharSet.Auto, ExactSpelling:=True)> _
Public Shared Sub Keybd_event(ByVal vk As Byte, ByVal scan As Byte, ByVal flags As Integer, ByVal extrainfo As Integer)
End Sub

Gerard.Brazil

SendInput?

Since this function has been superseded, what is the SendInput equivilant of the SetNumLock example?

JackTripper

Scan Codes

Key 	Scan Code
~   ` 	29
!  1 	2
@  2 	3
#  3 	4
$  4 	5
%  5 	6
^  6 	7
&  7 	8
*  8 	9
(  9 	0A
)  0 	0B
_   -	0C
+   = 	0D
Backspace 	0E
Tab 	0F
Q 	10
W 	11
E 	12
R 	13
T 	14
Y 	15
U 	16
I 	17
O 	18
P 	19
{  [ 	1A
}  ] 	1B
|  \ 	2B
Caps Lock 	3A
A 	1E
S 	1F
D 	20
F 	21
G 	22
H 	23
J 	24
K 	25
L 	26
:   ; 	27
“  ‘ 	28
Enter 	1C
L SHIFT 	2A
Z 	2C
X 	2D
C 	2E
V 	2F
B 	30
N 	31
M 	32
<  , 	33
>  . 	34
?  / 	35
R SHIFT 	36
L CTRL 	1D
L ALT 	38
Space Bar 	39
R ALT 	E0 38
R CTRL 	E0 1D
Insert 	E0 52
Delete 	E0 53
L Arrow 	E0 4B
Home 	E0 47
End 	E0 4F
Up Arrow 	E0 48
Dn Arrow 	E0 50
Page Up 	E0 49
Page Down 	E0 51
R Arrow 	E0 4D
Num Lock 	45
Numeric 7 	47
Numeric 4 	4B
Numeric 1 	4F
Numeric / 	E0 35
Numeric 8 	48
Numeric 5 	4C
Numeric 2 	50
Numeric 0 	52
Numeric * 	37
Numeric 9 	49
Numeric 6 	4D
Numeric 3 	51
Numeric . 	53
Numeric - 	4A
Numeric + 	4E
Numeric Enter 	E0 1C
Esc 	1
F1 	3B
F2 	3C
F3 	3D
F4 	3E
F5 	3F
F6 	40
F7 	41
F8 	42
F9 	43
F10	44
F11 	57
F12 	58
Print Screen 	??
Scroll Lock 	46
Pause 		??
Left Win 		E0 5B
Right Win 		E0 5C
Application 	E0 5D
ACPI Power 	E0 5E
ACPI Sleep 	E0 5F
ACPI Wake 	E0 63