MSflexgrid支援滑鼠滾輪事件

讓MSflexgrid支援滑鼠滾輪事件作者:枕善居主 / 查看次數: 10423 / 評論: 7http://www.mndsoft.com/blog/VB6/0923.html以下程式放在一個公用模組中，
在表單中的form_load事件中　寫　HookWheel　me.hwnd
在表單中的form_unload事件中　寫　UnHookWheel　me.hwnd
在表格的GotFocus事件中　set CtlWheel=MSFlexGrid1  '( 表格名稱，根據具體情況，修改這個名稱)

在表格的LostFocus事件中　set CtlWheel=Nothing'( 表格名稱，根據具體情況，修改這個名稱)

Option Explicit

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 Const GWL_WNDPROC   As Long = (-4)
Private Const WM_MOUSEWHEEL As Long = &H20A

Private m_OldWindowProc As Long

Public CtlWheel As Object

Public Sub HookWheel(ByVal frmHwnd)

    m_OldWindowProc = SetWindowLong(frmHwnd, GWL_WNDPROC, AddressOf pvWindowProc)
End Sub

Public Sub UnHookWheel(ByVal hwnd As Long)
    Dim lngReturnValue As Long
    lngReturnValue = SetWindowLong(hwnd, GWL_WNDPROC, m_OldWindowProc)
    
End Sub

Private Function pvWindowProc(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    On Error GoTo errH
    
    Select Case wMsg
    
        Case WM_MOUSEWHEEL
            If Not CtlWheel Is Nothing Then
                 If TypeOf CtlWheel Is MSFlexGrid Then
                     With CtlWheel
                    
                             Select Case wParam
                             Case Is > 0
        
                                If CtlWheel.TopRow > 0 Then
                                    CtlWheel.TopRow = CtlWheel.TopRow - 1
                                End If
                                
                             Case Else
                               
                                CtlWheel.TopRow = CtlWheel.TopRow + 1
                                
                             End Select
                      End With
                  End If
                  
           End If
    End Select
    
errH:
    
    pvWindowProc = CallWindowProc(m_OldWindowProc, hwnd, wMsg, wParam, lParam)
End Function