C / C++ / MFC

void CPNGButton::OnLButtonDown(UINT nFlags, CPoint point)
{
	SetCapture();
	SetPNG2Button(m_strMouseDownImagePath);
	CStatic::OnLButtonDown(nFlags, point);
}

void CPNGButton::OnLButtonUp(UINT nFlags, CPoint point)
{
	SetPNG2Button(m_strMouseMoveImagePath);
	CStatic::OnLButtonUp(nFlags, point);
}

void CPNGButton::OnMouseMove(UINT nFlags, CPoint point)
{
	SetCapture();
	CRect rc;
	GetClientRect(rc);
	if (rc.PtInRect(point))
	{
		if (!m_isPointInWnd)
		{
			OnMouseEnter();
			m_isPointInWnd = TRUE;
		}
	}
	else
	{
		SetPNG2Button(m_strMouseAwayImagePath);
		ReleaseCapture();
		m_isPointInWnd = FALSE;
	}
	CStatic::OnMouseMove(nFlags, point);
}

void CPNGButton::OnMouseEnter()
{
	SetPNG2Button(m_strMouseMoveImagePath);
}