mianwindow鼠标左键单击拖拽移动

void MainWindow::mousePressEvent(QMouseEvent* event)
{
    if(event->button()==Qt::LeftButton)
    {
        drag=true;
        pos=event->pos();
    }
}

void MainWindow::mouseMoveEvent(QMouseEvent* event)
{
    if(this->drag)
    {
        QPoint npos = event->pos()-this->pos;
        Qpoint nposs=Qpoint(this->x()+npos.x(),this->y()+npos.y());
        this->move(nposs);
    }
}

void MainWindow::mouseReleaseEvent(QMouseEvent* event)
{
    if(event->button()==Qt::LeftButton)
    {
        drag=false;
    }
}

drag类成员变量

pos类成员变量