'Module1 Option Explicit 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 uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long Public Declare Function GetProp Lib "user32" Alias "GetPropA" (ByVal hwnd As Long, ByVal lpString As String) As Long Public Declare Function SetProp Lib "user32" Alias "SetPropA" (ByVal hwnd As Long, ByVal lpString As String, ByVal hData As Long) As Long Public Declare Function RemoveProp Lib "user32" Alias "RemovePropA" (ByVal hwnd As Long, ByVal lpString As String) As Long Public Const GWL_WNDPROC = (-4&) Public Const WM_WINDOWPOSCHANGING = &H46& Public Type WINDOWPOS hwnd As Long hWndInsertAfter As Long x As Long y As Long cx As Long cy As Long flags As Long End Type Public Const HWND_BOTTOM = &H1& Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long) Public Function WinPropBag_ProcAddress(ByVal hwnd As Long, ByVal fStoreValue As Boolean, Optional ByVal lProcAddress As Long = 0, Optional ByVal fRemoveProp As Boolean = False) As Long If fStoreValue Then '保存属性 SetProp hwnd, "MY_WINPROP_PROCADDRESS", lProcAddress Else '取出属性 WinPropBag_ProcAddress = GetProp(hwnd, "MY_WINPROP_PROCADDRESS") If fRemoveProp Then '删除属性 RemoveProp hwnd, "MY_WINPROP_PROCADDRESS" End If End If End Function Public Sub Subclassing(ByVal hWndTarget As Long, Optional ByVal fUnsubclassing As Boolean = False) If fUnsubclassing Then WinPropBag_ProcAddress hWndTarget, True, SetWindowLong(hWndTarget, GWL_WNDPROC, AddressOf MyWindowProc) Else SetWindowLong hWndTarget, GWL_WNDPROC, WinPropBag_ProcAddress(hwnd:=hWndTarget, fStoreValue:=False, fRemoveProp:=True) End If End Sub Public Function MyWindowProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long If uMsg = WM_WINDOWPOSCHANGING Then '可以这样写 Dim ut As WINDOWPOS CopyMemory ut, ByVal lParam, Len(ut) ut.hWndInsertAfter = HWND_BOTTOM CopyMemory ByVal lParam, ut, Len(ut) '也可以这接这样写 'CopyMemory ByVal lParam + 4, HWND_BOTTOM, 4 End If MyWindowProc = CallWindowProc(WinPropBag_ProcAddress(hwnd, False), hwnd, uMsg, wParam, lParam) End Function
'Form1 Private Sub Form_Load() Subclassing Me.hwnd, True End Sub Private Sub Form_Unload(Cancel As Integer) Subclassing Me.hwnd, False End Sub 
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