GetAsyncKeyState

[jesper]

How can I catch all keyboard presses in the system.Can I use GetAsyncKeyState function ? Or must I use SetWindowsHookEx ? Please send me source code in the answer.

[Vlatko]

To monitor all keys pressed any time (even when your form isn't active) using a GlobalHook you must put the HookProc in a DLL file which Vb can't make.C++ can. As an alternative you can use this code.

'in a module
Declare Function SetTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Declare Function KillTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long) As Long
Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer

Function GetPressedKey() As String
    For Cnt = 32 To 128 'or 32 to 256
        'Get the keystate of a specified key
        If GetAsyncKeyState(Cnt) <> 0 Then
            GetPressedKey = Chr$(Cnt)
            Exit For
        End If
    Next Cnt
End Function
Sub TimerProc(ByVal hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long)
    Ret = GetPressedKey
    If Ret <> sOld Then
        sOld = Ret
        sSave = sSave + sOld
    End If
'sSave contains pressed keys
End Sub

In a form

Private Sub Form_Load()
SetTimer Me.hwnd, 0, 1, AddressOf TimerProc
End Sub

Private Sub Form_Unload(Cancel As Integer)
KillTimer Me.hwnd, 0
End Sub

[Edited by Vlatko on 10-29-2000 at 03:56 PM]

It might be a good idea to include key 13 (Return) as well.