//控制死窗体
    int width = this->geometry().width();
    int height = this->geometry().height();
    this->setFixedSize(width,height);

 　　//定时器的使用
     　QTimer *serialReadTimer = new QTimer;        
　　　 connect(serialReadTimer,SIGNAL(timeout()),this,SLOT(readSerial()));
      serialReadTimer->start(100);