如何在QGraphicsScene中放置QFrame？

Question

我想在QGraphicsScene中以垂直順序依次放置3個QFrame。 我試圖使用QHBoxLayout和QLayout，沒有任何東西，QGraphicsScene不接受QLayout。

QFrame * top = new QFrame; 
QFrame * middle = new QFrame; 
QFrame * bottom = new QFrame; 

top->setFrameStyle(QFrame::StyledPanel | QFrame::Plain); 
middle->setFrameStyle(QFrame::StyledPanel | QFrame::Plain); 
bottom->setFrameStyle(QFrame::StyledPanel | QFrame::Plain); 

top->setLineWidth(1); 
middle->setLineWidth(1); 
bottom->setLineWidth(1); 

top->setFixedWidth(400); 
top->setFixedHeight(150); 
middle->setFixedWidth(400); 
middle->setFixedHeight(250); 
bottom->setFixedWidth(400); 
bottom->setFixedHeight(150); 

scene = new QGraphicsScene; 
scene->setSceneRect(0, 0, 400, 550); 
scene->addWidget(top); 
scene->addWidget(middle); 
scene->addWidget(bottom); 

setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff); 
setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff); 
setFixedSize(400, 550); 
setScene(scene); 
show(); 

我該怎麼做才能使它工作？

Answer 1

QFrame * top = new QFrame; 
QFrame * middle = new QFrame; 
QFrame * bottom = new QFrame; 

top->setFrameStyle(QFrame::StyledPanel | QFrame::Plain); 
middle->setFrameStyle(QFrame::StyledPanel | QFrame::Plain); 
bottom->setFrameStyle(QFrame::StyledPanel | QFrame::Plain); 

top->setLineWidth(1); 
middle->setLineWidth(1); 
bottom->setLineWidth(1); 

scene = new QGraphicsScene; 
scene->setSceneRect(0, 0, 400, 550); 
QGraphicsWidget *topWidget = scene->addWidget(top); 
QGraphicsWidget *midWidget = scene->addWidget(middle); 
QGraphicsWidget *botWidget = scene->addWidget(bottom); 

QGraphicsGridLayout *layout = new QGraphicsGridLayout; 
layout->addItem(topWidget, 0, 0); 
layout->addItem(midWidget, 1, 0); 
layout->addItem(botWidget, 2, 0); 

QGraphicsWidget *form = new QGraphicsWidget; 
form->setLayout(layout); 
form->setPreferredSize(400,500); 
scene->addItem(form); 


setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff); 
setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff); 

setFixedSize(400, 550); 
setScene(scene); 
show();