What is the right way for an object to have a collection of a QObject derived class?

六眼飞鱼酱① 提交于 2019-12-07 18:18:48

问题


I'm trying to make a class exposing a collection(or several) of a QObject derived class(with its own qt properties) qt properties I can use in qml.

According to http://qt-project.org/doc/qt-5.0/qtcore/qobject.html#no-copy-constructor-or-assignment-operator qt doesn't play well with copy constructors.

So I used QList<QObject derived class> (my first idea) I can't pass the list by reference(or at least I think thats what the compiler errors implies)(needs copies) and am having a hard time figuring out howto add items to the list.

Should I use QList<QObject derived class *> or QList<SomeQTSmartPointer<QObject derived class>> or something else?


回答1:


Should I use QList<QObject derived class *> or QList<SomeQTSmartPointer<QObject derived class>> or something else?

Both are fine, but it is better to stick to the former through the Qt parent/child mechanism in general. This would be the most Qt'ish way of managing it in general:

QList<MyClass*> list;
list.append(new MyClass(parent);

You could also use Qt smart pointers like QPointer, QScopedPointer or QSharedPointer as follows:

QList<QShardPointer<MyClass> > list;
// Being explicit to be more comprehensive, but it is not necessary
list.append(QSharedPointer<MyClass>(new MyClass());

This will work with both pre C++11 and post.




回答2:


Well, both QList<Derived*> and QList<std::unique_ptr<Derived>> will do. If you are using the Qt default garbage collector (with the parent-child tree) you can just use:

QList<Derived*> list;
list.push_back(new Other(parent, ...));

otherwise you should use the second:

QList<std::unique_ptr<Derived>> list;
list.push_back(new Other(...));


来源:https://stackoverflow.com/questions/21120458/what-is-the-right-way-for-an-object-to-have-a-collection-of-a-qobject-derived-cl

易学教程内所有资源均来自网络或用户发布的内容,如有违反法律规定的内容欢迎反馈
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!