QT6 源（125）条目角色，枚举类 ItemDataRole ：模型视图架构里，item 条目里可以存储不同角色的的数据。本枚举类描述了这些角色的集合

（1）本枚举类定义于头文件 qnamespace . h ：

//QVariant QComboBox::itemData(int index, int role = Qt::UserRole) const;
//模型中的每个项目都有一组与之关联的数据元素，每个数据元素都有自己的角色。
//视图使用这些角色向模型指示它需要哪种类型的数据。自定义模型应返回这些类型的数据。
enum ItemDataRole {     //本枚举类用于组合框里, Item等控件里获取条目的数据
    DisplayRole = 0,
    //The key data to be rendered in the form of text. (QString)
    
    DecorationRole = 1,
    //The data to be rendered as a decoration in the form of an icon.
    //  (QColor, QIcon or QPixmap)
    
    EditRole = 2,
    //The data in a form suitable for editing in an editor. (QString)
    
    ToolTipRole = 3, //The data displayed in the item's tooltip. (QString)
    StatusTipRole = 4, //The data displayed in the status bar. (QString)
    
    WhatsThisRole = 5,
    //The data displayed for the item in "What's This?" mode. (QString)
    
    // Metadata：Roles describing appearance and meta data (with associated types):
    FontRole =  6,
    //The font used for items rendered with the default delegate. (QFont)
    
    TextAlignmentRole =  7,
    //The alignment of the text for items rendered with the default delegate.
    //  (Qt::Alignment)
    
    BackgroundRole =  8, //The background brush used for
    //  items rendered with the default delegate. (QBrush)
    
    ForegroundRole =  9, //The foreground brush (text color, typically) used for
    //  items rendered with the default delegate. (QBrush)
    
    CheckStateRole = 10, //This role is used to obtain the
    //  checked state of an item. (Qt::CheckState)
    
    // Accessibility ：Accessibility roles (with associated types):
    AccessibleTextRole = 11, //The text to be used by
    //accessibility extensions and plugins, such as screen readers. (QString)
    
    AccessibleDescriptionRole = 12,
    //A description of the item for accessibility purposes. (QString)
    
    // More general purpose
    SizeHintRole = 13,
    InitialSortOrderRole = 14,
    
    // Internal UiLib roles. Start worrying when public roles go that high.
    DisplayPropertyRole = 27,
    DecorationPropertyRole = 28,
    ToolTipPropertyRole = 29,
    StatusTipPropertyRole = 30,
    WhatsThisPropertyRole = 31,
    
    // Reserved
    UserRole = 0x0100
    //The first role that can be used for application-specific purposes
    
};

（2）给个图，易于理解 ：

（3）

谢谢