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VB6/VBA中跟踪鼠标移出窗体控件事件(类模块成员函数指针CHooker类应用)

前几天发了一篇博文,是关于获取VB类模块成员函数指针的内容(http://www.cnblogs.com/alexywt/p/5880993.html);今天我就发一下我的应用实例。

VB中默认是没有鼠标移出事件响应的,而这个事件其实在项目开发中,实用性很强,很多时候需要在鼠标移出窗体或控件时做些事情;没有这个事件会感觉很费力;

今天我所说的实际案例就是,在窗体上,设计一个SplitterBar控件,窗体的最终用户使用这个控件可以在运行程序时任意调整其内部控件大小。

我在第二篇参考博文作者开发的CHooker类上做了部分修改(对应以下代码中的中文注释部分代码),使该类能够跟踪鼠标移开事件,代码如下:

  1 Option Explicit  2   3 Private Type TRACKMOUSEEVENTTYPE  4     cbSize As Long  5     dwFlags As Long  6     hwndTrack As Long  7     dwHoverTime As Long  8 End Type  9  10 Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long) 11 Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long 12 Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long 13 Private Declare Function IsWindow Lib "user32" (ByVal hWnd As Long) As Long 14 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 15 Private Declare Function TrackMouseEvent Lib "user32" (lpEventTrack As TRACKMOUSEEVENTTYPE) As Long 16  17 Private Const GWL_WNDPROC = (-4) 18 Private Const WM_NCDESTROY = &H82 19 Private Const WM_MOUSEMOVE = &H200 20 Private Const TME_LEAVE = &H2& 21 Private Const WM_MOUSELEAVE = &H2A3& 22  23 Public Event WindowProc(ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long, bCallNext As Boolean, lReturn As Long) 24  25 Private m_hwnd As Long, m_NewProc As Long, m_OldProc As Long 26 Private m_TrackMouseLeave As Boolean        m_TrackMouseLeave设置在Hook时是否开启跟踪鼠标移开事件,是否正在跟踪移动事件 27 Private m_Tracking As Boolean               跟踪移开事件时,标识当前是否正在跟踪移动事件 28  29 Private Sub Class_Initialize() 30     m_NewProc = GetClassProcAddr(Me, 5, 4, True) 31 End Sub 32  33 Private Sub Class_Terminate() 34     Call Unbind 35 End Sub 36  37 Public Function Bind(ByVal hWnd As Long, Optional TrackMouseLeave As Boolean = False) As Boolean 38     Call Unbind 39     If IsWindow(hWnd) Then m_hwnd = hWnd 40     m_OldProc = SetWindowLong(m_hwnd, GWL_WNDPROC, m_NewProc) 41     Bind = CBool(m_OldProc) 42     m_TrackMouseLeave = TrackMouseLeave 保存用户传递的跟踪鼠标移开事件设置 43 End Function 44  45 Public Function Unbind() As Boolean 46     If m_OldProc <> 0 Then Unbind = CBool(SetWindowLong(m_hwnd, GWL_WNDPROC, m_OldProc)) 47     m_OldProc = 0 48 End Function 49  50 Private Function WindowProcCallBack(ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long 51     Dim bCallNext As Boolean, lReturn As Long 52     Dim tTrackML As TRACKMOUSEEVENTTYPE 一个移开事件结构声明 53      54     bCallNext = True 55      56     RaiseEvent WindowProc(Msg, wParam, lParam, bCallNext, lReturn) 57     当用户需要跟踪鼠标移开事件时 58     If m_TrackMouseLeave Then 59         鼠标在其上移动,当前未标识为跟踪状态(第一次或者移开鼠标后重新移动回来时) 60         If Msg = WM_MOUSEMOVE And m_Tracking = False Then 61             m_Tracking = True 62             initialize structure 63             tTrackML.cbSize = Len(tTrackML) 64             tTrackML.hwndTrack = hWnd 65             tTrackML.dwFlags = TME_LEAVE 66             start the tracking 67             TrackMouseEvent tTrackML 68         End If 69         鼠标移开时,取消跟踪状态 70         If Msg = WM_MOUSELEAVE Then m_Tracking = False 71     End If 72      73     If bCallNext Then 74         WindowProcCallBack = CallWindowProc(m_OldProc, hWnd, Msg, wParam, lParam) 75     Else 76         WindowProcCallBack = lReturn 77     End If 78     If hWnd = m_hwnd And Msg = WM_NCDESTROY Then Call Unbind 79 End Function 80  81 Private Function GetClassProcAddr(obj As Object, ByVal Index As Long, _ 82    Optional ByVal ParamCount As Long = 4, Optional ByVal HasReturnValue As Boolean) As Long 83     Static lReturn As Long, pReturn As Long 84     Static AsmCode(50) As Byte 85  86     Dim i As Long, pThis As Long, pVtbl As Long, pFunc As Long 87  88     pThis = ObjPtr(obj) 89     CopyMemory pVtbl, ByVal pThis, 4 90     CopyMemory pFunc, ByVal pVtbl + (6 + Index) * 4, 4 91     pReturn = VarPtr(lReturn) 92     For i = 0 To UBound(AsmCode)                                填充nop 93         AsmCode(i) = &H90 94     Next 95     AsmCode(0) = &H55                                           push   ebp 96     AsmCode(1) = &H8B: AsmCode(2) = &HEC                        mov    ebp,esp 97     AsmCode(3) = &H53                                           push   ebx 98     AsmCode(4) = &H56                                           push   esi 99     AsmCode(5) = &H57                                           push   edi100     If HasReturnValue Then101         AsmCode(6) = &HB8                                       mov    offset lReturn102         CopyMemory AsmCode(7), pReturn, 4103         AsmCode(11) = &H50                                      push   eax104     End If105     For i = 0 To ParamCount - 1                                 push   dword ptr[ebp+xx]106         AsmCode(12 + i * 3) = &HFF107         AsmCode(13 + i * 3) = &H75108         AsmCode(14 + i * 3) = (ParamCount - i) * 4 + 4109     Next110     i = i * 3 + 12111     AsmCode(i) = &HB9                                           mov    ecx,this112     CopyMemory AsmCode(i + 1), pThis, 4113     AsmCode(i + 5) = &H51                                       push ecx114     AsmCode(i + 6) = &HE8                                       call 相对地址115     CopyMemory AsmCode(i + 7), pFunc - VarPtr(AsmCode(i + 6)) - 5, 4116     If HasReturnValue Then117         AsmCode(i + 11) = &HB8                                  mov    eax,offset lReturn118         CopyMemory AsmCode(i + 12), pReturn, 4119         AsmCode(i + 16) = &H8B                                  mov    eax,dword ptr[eax]120         AsmCode(i + 17) = &H0121     End If122     AsmCode(i + 18) = &H5F                                      pop    edi123     AsmCode(i + 19) = &H5E                                      pop    esi124     AsmCode(i + 20) = &H5B                                      pop    ebx125     AsmCode(i + 21) = &H8B: AsmCode(i + 22) = &HE5              mov    esp,ebp126     AsmCode(i + 23) = &H5D                                      pop    ebp127     AsmCode(i + 24) = &HC3                                      ret128     GetClassProcAddr = VarPtr(AsmCode(0))129 End Function

那么如何使用这个新构建的类,来实现我们的需求了?首先创建一个窗体,放置三个PictureBox,其中一个做为SplitterBar(name属性picture4),其余2个图片框的宽度将会由SplitterBar在运行时调整。

 1 Private Type POINTAPI 2     x As Long 3     y As Long 4 End Type 5  6 Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long 7  8 Private mCanMove      As Boolean 9 Private mPreCursorPos As POINTAPI10 Private mCurCursorPos As POINTAPI11 Private WithEvents mHooker As CHooker12 13 Private Sub MDIForm_Load()14     Set mHooker = New CHooker15     call mHooker.Bind(Picture4.hWnd, True)16 End Sub17 18 Private Sub MDIForm_Unload(Cancel As Integer)19     mHooker.Unbind20     Set mHooker = Nothing21 End Sub22 23 Private Sub mHooker_WindowProc(ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long, bCallNext As Boolean, lReturn As Long)24     If Msg = WM_MOUSELEAVE Then Me.MousePointer = 025 End Sub26 27 28 Private Sub picture4_MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)29     Call GetCursorPos(mPreCursorPos)30 End Sub31 32 Private Sub picture4_MouseMove(Button As Integer, Shift As Integer, x As Single, y As Single)33     Me.MousePointer = vbSizeWE34     If (Button And vbLeftButton) > 0 Then35         Call GetCursorPos(mCurCursorPos)36         mCanMove = True37         Picture4.Move Picture4.Left + (mCurCursorPos.x - mPreCursorPos.x) * mdlCommon.TwipsPerPixelX()38         mPreCursorPos = mCurCursorPos39     End If40 End Sub41 42 Private Sub picture4_MouseUp(Button As Integer, Shift As Integer, x As Single, y As Single)43     If mCanMove Then44         此处添加调整界面元素位置与大小的代码45     End If46 End Sub

mdlCommon.TwipsPerPixelX()函数是在模块mdlCommon的一个公共函数,相关代码如下:

 1 Private Declare Function GetDC Lib "user32" (ByVal hWnd As Long) As Long 2 Private Declare Function GetDeviceCaps Lib "gdi32" (ByVal hdc As Long, ByVal nIndex As Long) As Long 3 Private Declare Function ReleaseDC Lib "user32" (ByVal hWnd As Long, ByVal hdc As Long) As Long 4  5  6 Private Const HWND_DESKTOP As Long = 0 7 Private Const LOGPIXELSX   As Long = 88 8 Private Const LOGPIXELSY   As Long = 90 9 10 TwipsPerPixelX:屏幕水平方向上1像素转换为对应的缇值11 Public Function TwipsPerPixelX() As Single12     Dim lngDC As Long13 14     lngDC = GetDC(HWND_DESKTOP)15     TwipsPerPixelX = 1440& / GetDeviceCaps(lngDC, LOGPIXELSX)16     ReleaseDC HWND_DESKTOP, lngDC17 End Function18 19 TwipsPerPixelY:屏幕垂直方向上1像素转换为对应的缇值20 Public Function TwipsPerPixelY() As Single21     Dim lngDC As Long22 23     lngDC = GetDC(HWND_DESKTOP)24     TwipsPerPixelY = 1440& / GetDeviceCaps(lngDC, LOGPIXELSY)25     ReleaseDC HWND_DESKTOP, lngDC26 End Function

 

  

VB6/VBA中跟踪鼠标移出窗体控件事件(类模块成员函数指针CHooker类应用)