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查旧贴清洁工那个
例子
http://www.office-cn.net/bbs/dispbbs.asp?boardID=2&ID=8256
或(转旧贴)
1、打开 Access ,并打开示例数据库 Northwind.mdb.
2、在 VBE 界面建立一个新的模块,并加入以下代码:
Option Compare Database
Option Explicit
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
5、保存类模块,名字为:CMouseWheel
6、打开 form_Customers 类,加入以下代码:
Option Compare Database
Option Explicit
'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
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