原文链接: http://www.cnblogs.com/weiqubo/archive/2011/04/14/2016323.html
默认情况下,窗口是不响应 WM_MOUSELEAVE 和 WM_MOUSEHOVER 消息的,所以要使用 _TrackMouseEvent 函数来激活这两个消息。调用这个函数后,当鼠标在指定窗口上停留超过一定时间或离开窗口后,该函数会 Post 这两个消息到指定窗口。
使用方法:
1. 在对话框类中定义一个变量来标识是否追踪当前鼠标状态,之所以要这样定义是要避免鼠标已经在窗体之上时,一移动鼠标就不断重复产生 WM_MOUSEHOVER 。
BOOL _bMouseTrack=TRUE ;
2. 在 OnMouseMove 中调用 _TrackMouseEvent 函数
if (_bMouseTrack) // 若允许 追踪,则。
{
TRACKMOUSEEVENT csTME;
csTME.cbSize = sizeof (csTME);
csTME.dwFlags = TME_LEAVE|TME_HOVER;
csTME.hwndTrack = m_hWnd ;// 指定要 追踪 的窗口
csTME.dwHoverTime = 10; // 鼠标在按钮上停留超过 10ms ,才认为状态为 HOVER
::_TrackMouseEvent (&csTME); // 开启 Windows 的 WM_MOUSELEAVE , WM_MOUSEHOVER 事件支持
_bMouseTrack=FALSE ; // 若已经 追踪 ,则停止 追踪
}
(#add 摘自MSDN:The _TrackMouseEvent function posts messages when the mouse pointer leaves a window or hovers over a window for a specified amount of time. This function calls TrackMouseEvent if it exists, otherwise it emulates it.)
3. 在 OnMouseLeave 中再次允许追踪鼠标状态
_bMouseTrack=TRUE ;
4. 备注:这两个消息的映射要自己写
ON_MESSAGE(WM_MOUSEHOVER,OnMouseHover)
ON_MESSAGE(WM_MOUSELEAVE,OnMouseLeave)
注意:也可以用下面代码在PreTranslateMessage函数中接收,不需要自己写WM_MOUSELEASE和WM_MOUSEHOVER消息的响应函数(当然你要自己写也行):
if(pMsg-> message==WM_MOUSELEAVE)
AfxMessageBox( "mouse leave ");
else if(pMsg->message == WM_MOUSEHOVER)
AfxMessageBos("mouse leave");
return CDialog::PreTranslateMessage(pMsg);
附一个例子:
.h文件加入:
afx_msg LRESULT OnMouseLeave(WPARAM ,LPARAM );
afx_msg LRESULT OnMouseHover(WPARAM ,LPARAM );
.cpp文件加入:
ON_MESSAGE(WM_MOUSELEAVE,OnMouseLeave)
ON_MESSAGE(WM_MOUSEHOVER,OnMouseHover)
LRESULT CIconButton::OnMouseLeave(WPARAM wParam,LPARAM lParam)
{
m_bMouseTrack=TRUE ;
InvalidateRect(NULL);
return 0;
}
LRESULT CIconButton::OnMouseHover(WPARAM wParam,LPARAM lParam)
{
// 获取鼠标坐标
POINT point;
::GetCursorPos(&point);
ScreenToClient(&point) ;
// 亦用如下方法,推荐.OnMouseMove 也可用.
CPoint pt;
pt.x = LOWORD(lParam); // horizontal position of cursor
pt.y = HIWORD(lParam); // vertical position of cursor
// 还有如下,和上边其实是一样
POINT pt = {GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
CClientDC dc(this);
CRect rt;
GetClientRect(&rt);
dc.Draw3dRect(0, 0, m_rect.right-m_rect.left, m_rect.bottom-m_rect.top, RGB(0,0,0), RGB(10,10,10));
return 0;
}
void CIconButton::OnMouseMove(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
CButton::OnMouseMove(nFlags, point);
if (m_bMouseTrack)
{
TRACKMOUSEEVENT tme;
tme.cbSize=sizeof(TRACKMOUSEEVENT);
tme.dwFlags=TME_HOVER | TME_LEAVE;
tme.dwHoverTime=HOVER_DEFAULT;
tme.hwndTrack=m_hWnd;
_TrackMouseEvent(&tme);
m_bMouseTrack = FALSE;
}
}