方法一：
/// 获取窗口控件的屏幕位置，类似于ClientToScreen
QPoint GlobalPoint(widget->mapToGlobal(QPoint(0,0)));

方法二：
/// 获取窗口控件的屏幕位置
static QPoint getPos(QWidget* widget)
{
 if (NULL == widget)
 {
  return QPoint(-1,-1);
 }
 float px = 0;
 float py = 0;
 QWidget *parent = widget;
 QWidget *preParent= NULL;
 do
 {
  QPoint p = parent->pos();
  px += p.x();
  py += p.y();
  preParent = parent ;
  parentw = parent->parentWidget();
 
 } while (NULL != parent);
 QSize size = preParent->frameSize();
 QSize size2 = preParent->size();
 px = px + (size.width() - size2.width())/2;
 py = py + (size.height() - size2.height() - (size.width() - size2.width())/2);
 QPoint pr(px, py);
 return pr;
}