[RESOLVED] [VB6] - about Hook windows api procedure

[joaquim]

In your Form code

Private Sub Command1_Click()
 OldWindowProc = SetWindowLong(Me.hWnd, GWL_WNDPROC, AddressOf MyWindowProc)
End Sub
Private Sub Command2_Click()
 '
 ' Restore the old window procedure before exiting
 '
 SetWindowLong Me.hWnd, GWL_WNDPROC, OldWindowProc

End Sub
Private Sub Form_Unload(Cancel As Integer)
 Dim frm As Form
    
 '
 ' Restore the old window procedure before exiting
 '
 SetWindowLong Me.hWnd, GWL_WNDPROC, OldWindowProc
    
 Unload Me
End Sub

In your Module code

Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long

Public Const WM_LBUTTONDOWN = &H201

Public OldWindowProc As Long

Public Const GWL_WNDPROC& = (-4)
Public Function MyWindowProc(ByVal hWnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
 Dim Processed As Boolean
 
 Select Case uMsg
   Case WM_LBUTTONDOWN
     MsgBox "Left Button Down"
     Processed = True
   Case Else
     MyWindowProc = CallWindowProc(OldWindowProc, hWnd, uMsg, wParam, lParam)
 End Select
 
 If Processed Then
   MyWindowProc = CallWindowProc(OldWindowProc, hWnd, uMsg, wParam, lParam)
 End If
End Function

yes... i'm speak about these code.
what term you use for call it?
can i use these code for normal loop, or it's only for computer\user actions?
(can i calculate milliseconds with these code?)