将窗口设置为屏幕全屏

int desk_top_width = QApplication::desktop()->width();//huoqu桌面尺寸
int desk_top_high = QApplication::desktop()->height();
this->resize (desk_top_width, desk_top_high);//设置窗口大小为桌面大小
this->setWindowFlags (Qt::FramelessWindowHint); // 隐藏窗口标题