Attribute VB_Name = "hookmod"
Option Explicit

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 Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Declare Sub CopyMemory Lib "KERNEL32" Alias "RtlMoveMemory" ( _
    lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)

Public Const GWL_WNDPROC = -4

'在這里寫下要攔下消息的常量定義




Public defWndProc As Long

Type rect
        
        left As Long
        top As Long
        right As Long
        bottom As Long

End Type

                                                                      
Public Sub Hook(hwnd As Long)
If defWndProc = 0 Then defWndProc = SetWindowLong(hwnd, GWL_WNDPROC, AddressOf WindowProc)
End Sub
Public Sub UnHook(hwnd As Long)
If defWndProc > 0 Then
Call SetWindowLong(hwnd, GWL_WNDPROC, defWndProc)
defWndProc = 0
End If
End Sub
Public Function WindowProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long

If Msg = &H216 Then
     
     Dim WPOS As rect
     
     CopyMemory WPOS, ByVal lParam, Len(WPOS)
     
     Form2.top = WPOS.top
        
     Form2.left = WPOS.left + Form1.Width
  End If


WindowProc = CallWindowProc(defWndProc, hwnd, uMsg, wParam, lParam)
End Select
End Function