先来看看核心的函数之一的 FixMoving，该函数在OnMoving中被调用，FixMoving通过检测鼠标位置和窗口位置来决定窗口的收缩模式，并修正粘附边界时窗口的位置，从而达到像移动QQ时出现的效果。
void CQQHideWndDlg::FixMoving(UINT fwSide, LPRECT pRect)
{
POINT curPos;
GetCursorPos(&curPos);
INT screenHeight = GetSystemMetrics(SM_CYSCREEN);
INT screenWidth = GetSystemMetrics(SM_CXSCREEN);
INT height = pRect->bottom - pRect->top;
INT width = pRect->right - pRect->left;
if (curPos.y <= INTERVAL)
{ //粘附在上边
pRect->bottom = height - m_edgeHeight;
pRect->top = -m_edgeHeight;
m_hideMode = HM_TOP;
}
else if(curPos.y >= (screenHeight - INTERVAL - m_taskBarHeight))
{ //粘附在下边
pRect->top = screenHeight - m_taskBarHeight - height;
pRect->bottom = screenHeight - m_taskBarHeight;
m_hideMode = HM_BOTTOM;
}
else if (curPos.x < INTERVAL)
{ //粘附在左边
if(!m_isSizeChanged)
{
CRect tRect;
GetWindowRect(tRect);
m_oldWndHeight = tRect.Height();
}
pRect->right = width;
pRect->left = 0;
pRect->top = -m_edgeHeight;
pRect->bottom = screenHeight - m_taskBarHeight;
m_isSizeChanged = TRUE;
m_hideMode = HM_LEFT;
}
else if(curPos.x >= (screenWidth - INTERVAL))
{ //粘附在右边
if(!m_isSizeChanged)
{
CRect tRect;
GetWindowRect(tRect);
m_oldWndHeight = tRect.Height();
}
pRect->left = screenWidth - width;
pRect->right = screenWidth;
pRect->top = -m_edgeHeight;
pRect->bottom = screenHeight - m_taskBarHeight;
m_isSizeChanged = TRUE;
m_hideMode = HM_RIGHT;
}
else
{ //不粘附
if(m_isSizeChanged)
{ //如果收缩到两边,则拖出来后会变回原来大小
//在"拖动不显示窗口内容下"只有光栅变回原来大小
pRect->bottom = pRect->top + m_oldWndHeight;
m_isSizeChanged = FALSE;
}
if(m_isSetTimer)
{ //如果Timer开启了,则关闭之
if(KillTimer(1) == 1)
m_isSetTimer = FALSE;
}
m_hideMode = HM_NONE;
GetDlgItem(IDC_TIMER)->SetWindowText("Timer off");
}
}
收缩模式和位置决定后，剩下的工作就由最后两个核心函数完成了：实现收缩的DoHide()，实现伸展的DoShow()。在这两个过程中m_hsFinished，m_hiding 这两个变量起到很重要的控制作用。由于伸缩过程没完成时，hsFinished始终为FALSE，所以Timer 2 不会关闭，于是在OnTimer中会重复调用这两个函数之一，在这两个函数体内，窗口位置有规律地递减或递增就可以达到QQ的“抽屉”效果了，有趣的是即使伸缩过程还没完成，你也可以在这个过程中改变m_hiding这个值来决定他是伸还是缩，正如QQ一样。你可以把Timer 2 的事件间隔调大一点，然后在窗口伸缩时，鼠标来回地进出窗口就会很容易看到这样有趣的效果（还没缩进去又被拉了出来，或者还没拉出来又缩进去了）。
void CQQHideWndDlg::DoHide()
{
if(m_hideMode == HM_NONE)
return;
CRect tRect;
GetWindowRect(tRect);
INT height = tRect.Height();
INT width = tRect.Width();
INT steps = 0;
switch(m_hideMode)
{
case HM_TOP:
steps = height/HS_STEPS;
tRect.bottom -= steps;
if(tRect.bottom <= m_edgeWidth)
{ //你可以把下面一句替换上面的 ...+=|-=steps 达到取消抽屉效果
//更好的办法是添加个BOOL值来控制,其他case同样.
tRect.bottom = m_edgeWidth;
m_hsFinished = TRUE; //完成隐藏过程
}
tRect.top = tRect.bottom - height;
break;
case HM_BOTTOM:
steps = height/HS_STEPS;
tRect.top += steps;
if(tRect.top >= (GetSystemMetrics(SM_CYSCREEN) - m_edgeWidth))
{
tRect.top = GetSystemMetrics(SM_CYSCREEN) - m_edgeWidth;
m_hsFinished = TRUE;
}
tRect.bottom = tRect.top + height;
break;
case HM_LEFT:
steps = width/HS_STEPS;
tRect.right -= steps;
if(tRect.right <= m_edgeWidth)
{
tRect.right = m_edgeWidth;
m_hsFinished = TRUE;
}
tRect.left = tRect.right - width;
tRect.top = -m_edgeHeight;
tRect.bottom = GetSystemMetrics(SM_CYSCREEN) - m_taskBarHeight;
break;
case HM_RIGHT:
steps = width/HS_STEPS;
tRect.left += steps;
if(tRect.left >= (GetSystemMetrics(SM_CXSCREEN) - m_edgeWidth))
{
tRect.left = GetSystemMetrics(SM_CXSCREEN) - m_edgeWidth;
m_hsFinished = TRUE;
}
tRect.right = tRect.left + width;
tRect.top = -m_edgeHeight;
tRect.bottom = GetSystemMetrics(SM_CYSCREEN) - m_taskBarHeight;
break;
default:
break;
}