是让一个widget跟这你的鼠标移动吗?
如果是的话,解决方法是:
1. 声明
        QPoint last;
        QPoint pos;
    为该widget的数据成员
2. 为该widget添加方法
     void mousePressEvent(QMouseEvent *);
     void mouseMoveEvent(QMouseEvent *);
3. 实现方法
    void MyWidget::mousePressEvent(QMouseEvent *e)
{
    if(e->buttons()==Qt::LeftButton)
    {
        last=e->globalPos();
        pos=e->globalPos()-e->pos();
    }
}
void MyWidget::mouseMoveEvent(QMouseEvent *e)
{
    if(e->buttons() && Qt::LeftButton)
    {
        QPoint newpos = e->globalPos();
        QPoint upleft = pos + newpos - last;
        this->move(upleft);
    }
}