if(Dirc){ // 那就全放到if内就行了
QHBoxLayout* layout = new QHBoxLayout;
layout->addWidget(button1);
layout->addWidget(button2);
layout->addWidget(button3);
setLayout(layout);
}
else{
QVBoxLayout* layout = new QVBoxLayout;
layout->addWidget(button1);
layout->addWidget(button2);
layout->addWidget(button3);
setLayout(layout);
}