QGraphicsScene没有删除QWidget的功能

Question

QGraphicsScene has an addWidget(QWidget *) function, but no corresponding removeWidget(QWidget *) . It has only removeItem(QGraphicsItem *) .

How do I remove a QWidget?

Answer 1

Here's a basic sample, see if it works for you.

QGraphicsScene scene;   
QPushButton *button = new QPushButton; 

//Add item and obtain QGraphicsProxyWidget 
QGraphicsProxyWidget *proxy = scene.addWidget(button);

//Remove item
scene.removeItem(proxy);

Just remember to delete any memory you allocate.

Edit: After OP's comments, maybe this is what you want

//add item
QGraphicsProxyWidget *proxy = new QGraphicsProxyWidget;
proxy = scene.addWidget(button);

//remove item
scene.removeItem(button->graphicsProxyWidget());

Again, remember to delete proxy, or use a smart pointer.

Answer 2

I have a working solution figured out, but I do have some warnings appearing in the console. Here's a basic approximation of what I'm doing:

QGraphicsScene *scene = new QGraphicsScene();

// Add button
QPushButton button = new QPushButton( "Test", this );
scene->addWidget( button );

// Remove button
QGraphicsProxyWidget *proxy;
proxy = proxy->createProxyForChildWidget( button );
scene_->removeItem( proxy );
delete proxy;
proxy = NULL;
delete button;
button = NULL;

Here are the warnings I see though:

QGraphicsProxyWidget::setWidget: cannot embed widget 0x604a2c8 which is not a toplevel widget, and is not a child of an embedded widget QGraphicsProxyWidget::createProxyForChildWidget: top-level widget not in a QGraphicsScene QGraphicsScene::removeItem: cannot remove 0-item