Windows API Guide: GetClassInfo Function

Declare Function GetKeyState Lib "user32.dll" (ByVal nVirtKey As Long) As Integer

Platforms

Windows 95: Supported.
Windows 98: Supported.
Windows NT: Requires Windows NT 3.1 or later.
Windows 2000: Supported.
Windows CE: Requires Windows CE 1.0 or later.

Description & Usage

GetKeyState determines the current status of a key. The function both finds whether the key is currently pressed down or not, and determines if the key is currently toggled. The keyboard information retrieved by this function is thread-specific; its information does not necessarily reflect key states pertaining to the system as a whole.

Return Value

If the &H1 bit of the return value is set, the key is toggled. If the &H8000 bit of the return value is set, the key is currently pressed down.

Visual Basic-Specific Issues

None.

Parameters

nVirtKey

The virtual-key code of the key to read the status of. Windows NT, 2000: This could also be one of the following flags which distinguish between the left and right Ctrl, Alt, and Shift keys:

VK_LSHIFT: The left Shift key.
VK_RSHIFT: The right Shift key.
VK_LCONTROL: The left Ctrl key.
VK_RCONTROL: The right Ctrl key.
VK_LMENU: The left Alt key.
VK_RMENU: The right Alt key.

Constant Definitions

Const VK_LSHIFT = &HA0 Const VK_RSHIFT = &HA1 Const VK_LCONTROL = &HA2 Const VK_RCONTROL = &HA3 Const VK_LMENU = &HA4 Const VK_RMENU = &HA5

Example

' This code is licensed according to the terms and conditions listed here. ' Declarations and such needed for the example: ' (Copy them to the (declarations) section of a module.) Public Declare Function GetKeyState Lib "user32.dll" (ByVal nVirtKey As Long) As Integer ' Determine whether the Q key is currently being pressed. ' The code runs when button Command1 is pressed. Private Sub Command1_Click() Dim keystate As Integer  ' state of the Q key ' Get the state of the Q key as returned by the function. ' (vbKeyQ is a VB-defined constant for Q's virtual-key code) keystate = GetKeyState(vbKeyQ) ' Check the &H8000 bit of the return value. If keystate And &H8000 Then Debug.Print "The Q key is currently down." Else Debug.Print "The Q key is currently up." End If End Sub