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 GWL_WNDPROC = -4
Public Const WM_MouseWheel = &H20A
Public lpPrevWndProc As Long
Public Cmouse As CMouseWheel
Public Function WindowProc(ByVal hwnd As Long, _
ByVal uMsg As Long, _
ByVal wParam As Long, _
ByVal lParam As Long) As Long
'Look at the message passed to the window. If it is
'a mouse wheel message, call the FireMouseWheel procedure
'in the CMouseWheel class, which in turn raises the MouseWheel
'event. If the Cancel argument in the form event procedure is
'set to False, then we process the message normally, otherwise
'we ignore it. If the message is something other than the mouse
'wheel, then process it normally
Select Case uMsg
Case WM_MouseWheel
Cmouse.FireMouseWheel
If Cmouse.MouseWheelCancel = False Then
WindowProc = CallWindowProc(lpPrevWndProc, hwnd, uMsg, wParam, lParam)
End If
Case Else
WindowProc = CallWindowProc(lpPrevWndProc, hwnd, uMsg, wParam, lParam)
End Select
End Function
3、保存类，名为：basSubClassWindow
4、建立一个类模块，并且加入以下代码：
Option Compare Database
Option Explicit
Private frm As Access.Form
Private intCancel As Integer
Public Event MouseWheel(Cancel As Integer)
Public Property Set Form(frmIn As Access.Form)
'Define Property procedure for the class which
'allows us to set the Form object we are
'using with it. This property is set from the
'form class module.
Set frm = frmIn
End Property
Public Property Get MouseWheelCancel() As Integer
'Define Property procedure for the class which
'allows us to retrieve whether or not the Form
'event procedure canceled the MouseWheel event.
'This property is retrieved by the WindowProc
'function in the standard basSubClassWindow
'module.
MouseWheelCancel = intCancel
End Property
Public Sub SubClassHookForm()
'Called from the form's OnOpen or OnLoad
'event. This procedure is what "hooks" or
'subclasses the form window. If you hook the
'the form window, you must unhook it when completed
'or Access will crash.
lpPrevWndProc = SetWindowLong(frm.hwnd, GWL_WNDPROC, _
AddressOf WindowProc)
Set Cmouse = Me
End Sub
Public Sub SubClassUnHookForm()
'Called from the form's OnClose event.
'This procedure must be called to unhook the
'form window if the SubClassHookForm procedure
'has previously been called. Otherwise, Access will
'crash.
Call SetWindowLong(frm.hwnd, GWL_WNDPROC, lpPrevWndProc)
End Sub
Public Sub FireMouseWheel()
'Called from the WindowProc function in the
'basSubClassWindow module. Used to raise the
'MouseWheel event when the WindowProc function
'intercepts a mouse wheel message.
RaiseEvent MouseWheel(intCancel)
End Sub
'Declare a module level variable as the custom class
'and give us access to the class's events
Private WithEvents clsMouseWheel As CMouseWheel
Private Sub Form_Load()
'Create a new instance of the class,
'and set the class's Form property to
'the current form
Set clsMouseWheel = New CMouseWheel
Set clsMouseWheel.Form = Me
'Subclass the current form by calling
'the SubClassHookForm method in the class
clsMouseWheel.SubClassHookForm
End Sub
Private Sub Form_Close()
'Unhook the form by calling the
'SubClassUnhook form method in the
'class, and then destroy the object
'variable
clsMouseWheel.SubClassUnHookForm
Set clsMouseWheel.Form = Nothing
Set clsMouseWheel = Nothing
End Sub
Private Sub clsMouseWheel_MouseWheel(Cancel As Integer)
'This is the event procedure where you can
'decide what to do when the user rolls the mouse.
'If setting Cancel = True, we disable the mouse wheel
'in this form.
MsgBox "You cannot use the mouse wheel to scroll through records."
Cancel = True
End Sub
7、保存，并关闭。
注意：
不要立即打开窗体验证代码是否正确，否则你的access将陷入长时间的停顿，因为 VBE 已经被加载了。
立即退出 Access ，然后重新打开数据库，滚动滚轮，你将看到以下提示：
You cannot use the mouse wheel to scroll through records.
并且记录没有更改。