QModelRoleData 类

QModelRoleData 类保持角色和与该角色关联的数据。 更多...

头: #include <QModelRoleData>
CMake: find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake: QT += core
Since: Qt 6.0

公共函数

QModelRoleData (int role )
void clearData ()
QVariant & data ()
const QVariant & data () const
int role () const
void setData (T && value )

详细描述

QModelRoleData objects store an item role (which is a value from the Qt::ItemDataRole enumeration, or an arbitrary integer for a custom role) as well as the data associated with that role.

A QModelRoleData object is typically created by views or delegates, setting which role they want to fetch the data for. The object is then passed to models (see QAbstractItemModel::multiData ()), which populate the data corresponding to the role stored. Finally, the view visualizes the data retrieved from the model.

另请参阅 模型/视图编程 and QModelRoleDataSpan .

成员函数文档编制

[explicit] QModelRoleData:: QModelRoleData ( int role )

Constructs a QModelRoleData object for the given role .

另请参阅 Qt::ItemDataRole .

void QModelRoleData:: clearData ()

Clears the data held by this object. Note that the role is unchanged; only the data is cleared.

另请参阅 data ().

[constexpr] QVariant &QModelRoleData:: data ()

Returns the data held by this object as a modifiable reference.

另请参阅 setData ().

[constexpr] const QVariant &QModelRoleData:: data () const

Returns the data held by this object.

另请参阅 setData ().

[constexpr] int QModelRoleData:: role () const

Returns the role held by this object.

另请参阅 Qt::ItemDataRole .

[constexpr] template <typename T> void QModelRoleData:: setData ( T && value )

Sets the data held by this object to value . value must be of a datatype which can be stored in a QVariant .

另请参阅 data (), clearData (),和 Q_DECLARE_METATYPE .