Qt::ItemDataRole

目录

• #include <qnamespace.h>
• general purpose roles
• describing appearance and meta data
• Accessibility roles
• User roles
• code

#include <qnamespace.h>

    enum ItemDataRole {
        DisplayRole = 0,
        DecorationRole = 1,
        EditRole = 2,
        ToolTipRole = 3,
        StatusTipRole = 4,
        WhatsThisRole = 5,
        // Metadata
        FontRole = 6,
        TextAlignmentRole = 7,
        BackgroundColorRole = 8,
        BackgroundRole = 8,
        TextColorRole = 9,
        ForegroundRole = 9,
        CheckStateRole = 10,
        // Accessibility
        AccessibleTextRole = 11,
        AccessibleDescriptionRole = 12,
        // 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
    };

model中的每个item都有一组与之关联的数据元素，每个元素都有自己的role。view使用这些role向model指示它需要哪种类型的数据。自定义model应返回对应类型的数据。

general purpose roles

Constant	value	Description
Qt::DisplayRole	0	The key data to be rendered in the form of text. (QString)
Qt::DecorationRole	1	The data to be rendered as a decoration in the form of an icon. (QColor, QIcon or QPixmap)
Qt::EditRole	2	The data in a form suitable for editing in an editor. (QString)
Qt::ToolTipRole	3	The data displayed in the item's tooltip. (QString)
Qt::StatusTipRole	4	The data displayed in the status bar. (QString)
Qt::WhatsThisRole	5	The data displayed for the item in "What's This?" mode. (QString)
Qt::SizeHintRole	13	The size hint for the item that will be supplied to views. (QSize)

describing appearance and meta data

Constant	value	Description
Qt::FontRole	6	The font used for items rendered with the default delegate. (QFont)
Qt::TextAlignmentRole	7	The alignment of the text for items rendered with the default delegate. (Qt::Alignment)
Qt::BackgroundRole	8	The background brush used for items rendered with the default delegate. (QBrush)
Qt::BackgroundColorRole	8	expired, use Qt::BackgroundRole
Qt::ForegroundRole	9	The foreground brush (text color, typically) used for items rendered with the default delegate. (QBrush)
Qt::TextColorRole	9	expired, use Qt::ForegroundRole
Qt::CheckStateRole	10	This role is used to obtain the checked state of an item. (Qt::CheckState)
Qt::InitialSortOrderRole	14	This role is used to obtain the initial sort order of a header view section. (Qt::SortOrder). This role was introduced in Qt 4.8

Accessibility roles

constant	value	Description
Qt::AccessibleTextRole	11	The text to be used by accessibility extensions and plugins, such as screen readers. (QString)
Qt::AccessibleDescriptionRole	12	A description of the item for accessibility purposes. (QString)

User roles

constant	value	Description
Qt::UserRole	0x0100	The first role that can be used for application-specific purposes

code

enum CustomRole{
    NAME = Qt::UserRole,
    AGE
};

setData(QString("abc"), NAME);
data(NAME);


if (Qt::DisplayRole == role){return QString();}
else if (Qt::TextColorRole == role) {return QColor(255, 0, 0);}
else if (Qt::ToolTipRole == role){ return QString();}