[英]What should overloaded QAbstractItemModel::flags return for non valid QModelIndex?
I'm reading a QT documentation for a model/view architecture https://doc.qt.io/qt-5/model-view-programming.html#making-the-model-editable and see an example of overloading QAbstractItemModel::flags method that returns Qt::ItemIsEnabled
for invalid index:我正在阅读模型/视图架构的 QT 文档https://doc.qt.io/qt-5/model-view-programming.html#making-the-model-editable并查看重载 QAbstractItemModel 的示例: :flags 方法为无效索引返回Qt::ItemIsEnabled
:
Qt::ItemFlags StringListModel::flags(const QModelIndex &index) const
{
if (!index.isValid())
return Qt::ItemIsEnabled;
return QAbstractItemModel::flags(index) | Qt::ItemIsEditable;
}
So, if index is not valid, ie can have negative row, we still consider that user can interact with it.所以,如果索引无效,即可以有负行,我们仍然认为用户可以与之交互。 Is there any sence for that logic?这种逻辑有什么意义吗? For me, returning Qt::NoItemFlags
in that case could be more logical对我来说,在这种情况下返回Qt::NoItemFlags
可能更合乎逻辑
What you need is Qt::NoItemFlags
: https://doc.qt.io/Qt-5/qt.html#ItemFlag-enum .你需要的是Qt::NoItemFlags
: https Qt::NoItemFlags
。
It's the default value of the flags enum (since it's the first item in the enum).它是标志枚举的默认值(因为它是枚举中的第一项)。 You could also write it as return {};
你也可以把它写成return {};
, and it will give you the same Qt::NoItemFlags
. ,它会给你相同的Qt::NoItemFlags
。
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