新建一個 ActiveX DLL 工程，名稱 SmartSubClassLib ' 以下代碼放在標准模塊裡，模塊名 mSmartSubClass ' ---------------------------------------------------- ' Module mSmartSubClass ' ' Version... 1.0 ' Date...... 24 April 2001 ' ' Copyright (C) 2001 Andr閟 Pons (
[email protected]) ' ---------------------------------------------------- 'API declarations: Option EXPlicit Public Const SSC_OLDPROC = "SSC_OLDPROC" Public Const SSC_OBJADDR = "SSC_OBJADDR" Private Declare Function GetProp Lib "user32" Alias "GetPropA" ( _ ByVal hWnd As Long, _ ByVal lpString As String) As Long Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" ( _ Destination As Any, _ Source As Any, _ ByVal Length As Long) ' Function StartSubclassWindowProc() ' ' This is the first windowproc that receives messages ' for all subclassed windows. ' The aim of this function is to just collect the message ' and deliver it to the right SmartSubClass instance. ' Public Function SmartSubClassWindowProc( _ ByVal hWnd As Long, _ ByVal uMsg As Long, _ ByVal wParam As Long, _ ByVal lParam As Long) As Long Dim lRet As Long Dim oSmartSubClass As SmartSubClass 'Get the memory address of the class instance... lRet = GetProp(hWnd, SSC_OBJADDR) If lRet 0 Then 'oSmartSubClass will point to the class instance 'without incrementing the class reference counter... CopyMemory oSmartSubClass, lRet, 4 'Send the message to the class instance... SmartSubClassWindowProc = oSmartSubClass.WindowProc(hWnd, _ uMsg, wParam, lParam) 'Remove the address from memory... CopyMemory oSmartSubClass, 0&, 4 End If End Function ' 以下代碼放在類模塊裡，模塊名 SmartSubClass ' ---------------------------------------------------- ' Class SmartSubClass ' ' Version... 1.0 ' Date...... 24 April 2001 ' ---------------------------------------------------- Option Explicit 'Public event: Public Event NewMessage( _ ByVal hWnd As Long, _ ByRef uMsg As Long, _ ByRef wParam As Long, _ ByRef lParam As Long, _ ByRef Cancel As Boolean) 'Private variables: Private m_hWnds() As Long 'API declarations: Private Const GWL_WNDPROC = (-4) Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _ ByVal hWnd As Long, _ ByVal nIndex As Long) As Long Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _ ByVal hWnd As Long, _ ByVal nIndex As Long, _ ByVal dwNewLong As Long) As Long Private 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 Private Declare Function GetProp Lib "user32" Alias "GetPropA" ( _ ByVal hWnd As Long, _ ByVal lpString As String) As Long Private Declare Function SetProp Lib "user32" Alias "SetPropA" ( _ ByVal hWnd As Long, _ ByVal lpString As String, _ ByVal hData As Long) As Long Private Declare Function RemoveProp Lib "user32" Alias "RemovePropA" ( _ ByVal hWnd As Long, _ ByVal lpString As String) As Long Private Declare Function IsWindow Lib "user32" ( _ ByVal hWnd As Long) As Long ' ' Function SubClassHwnd ' ' This is the core function in this class. ' You can use it to both subclass and unsubclass a window. ' Once a window is subclassed the event NewMessage will ' be raised every time a message is sent to the window. ' Public Function SubClassHwnd(ByVal hWnd As Long, _ ByVal bSubClass As Boolean) As Boolean Dim lRet As Long lRet = 0 'Make sure that hWnd is a valid window handler... If IsWindow(hWnd) Then If bSubClass Then 'We are subclassing a window... 'Make sure that the window wasn't already subclassed... If GetProp(hWnd, SSC_OLDPROC) = 0 Then 'Now we subclass the window by changing its windowproc lRet = SetWindowLong(hWnd, GWL_WNDPROC, _ AddressOf SmartSubClassWindowProc) 'Check if we've managed to subclass... If lRet 0 Then 'Store the old windowproc and the memory ' address of this class... SetProp hWnd, SSC_OLDPROC, lRet SetProp hWnd, SSC_OBJADDR, ObjPtr(Me) 'Add the window to an internal list of ' subclassed windows... pAddHwndToList hWnd End If End If Else 'We are unsubclassing a window... 'Get the old windowproc... lRet = GetProp(hWnd, SSC_OLDPROC) If lRet 0 Then 'Unsubclass the window... lRet = SetWindowLong(hWnd, GWL_WNDPROC, lRet) End If 'Remove any extra information... RemoveProp hWnd, SSC_OLDPROC RemoveProp hWnd, SSC_OBJADDR 'Remove the window from the internal list... pRemoveHwndFromList hWnd End If Else 'If hWnd is not a valid window, 'make sure that there isn't stored garbage... RemoveProp hWnd, SSC_OLDPROC RemoveProp hWnd, SSC_OBJADDR pRemoveHwndFromList hWnd End If SubClassHwnd = (lRet 0) End Function ' ' Function WindowProc ' ' This is the link between the windowproc and the class instance. ' Every time SmartSubClassWindowProc receives a window message, ' it will post it to the right class instance. ' Friend Function WindowProc( _ ByVal hWnd As Long, _ ByVal uMsg As Long, _ ByVal wParam As Long, _ ByVal lParam As Long) As Long Dim lRet As Long Dim bCancel As Boolean bCancel = False WindowProc = 0 'Raise the event NewMessage... 'This will tell the owner of the class variable that a 'new message is ready to be processed. 'The owner will be able to cancel the message by setting 'the variable bCancel to True. RaiseEvent NewMessage(hWnd, uMsg, wParam, lParam, bCancel) 'If the event hasn't been canceled by the owner 'we need to send it to the original windowproc If Not bCa
