QIcon 类

QIcon 类提供在不同模式和状态下的可伸缩图标。更多...

头：	#include <QIcon>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Gui) target_link_libraries(mytarget PRIVATE Qt6::Gui)
qmake:	QT += gui

公共类型

enum	Mode { Normal, Disabled, Active, Selected }
enum	State { Off, On }
`(从 6.7 起)` enum class	ThemeIcon { AddressBookNew, ApplicationExit, AppointmentNew, CallStart, CallStop, …, WeatherStorm }

公共函数

	QIcon ()
	QIcon (const QPixmap & pixmap )
	QIcon (const QString & fileName )
	QIcon (QIconEngine * engine )
	QIcon (const QIcon & other )
	QIcon (QIcon && other )
	~QIcon ()
QSize	actualSize (const QSize & size , QIcon::Mode mode = Normal, QIcon::State state = Off) const
void	addFile (const QString & fileName , const QSize & size = QSize(), QIcon::Mode mode = Normal, QIcon::State state = Off)
void	addPixmap (const QPixmap & pixmap , QIcon::Mode mode = Normal, QIcon::State state = Off)
QList<QSize>	availableSizes (QIcon::Mode mode = Normal, QIcon::State state = Off) const
qint64	cacheKey () const
bool	isMask () const
bool	isNull () const
QString	name () const
void	paint (QPainter * painter , const QRect & rect , Qt::Alignment alignment = Qt::AlignCenter, QIcon::Mode mode = Normal, QIcon::State state = Off) const
void	paint (QPainter * painter , int x , int y , int w , int h , Qt::Alignment alignment = Qt::AlignCenter, QIcon::Mode mode = Normal, QIcon::State state = Off) const
QPixmap	pixmap (const QSize & size , QIcon::Mode mode = Normal, QIcon::State state = Off) const
QPixmap	pixmap (int w , int h , QIcon::Mode mode = Normal, QIcon::State state = Off) const
QPixmap	pixmap (int extent , QIcon::Mode mode = Normal, QIcon::State state = Off) const
`(从 6.0 起)` QPixmap	pixmap (const QSize & size , qreal devicePixelRatio , QIcon::Mode mode = Normal, QIcon::State state = Off) const
void	setIsMask (bool isMask )
void	swap (QIcon & other )
QVariant	operator QVariant () const
QIcon &	operator= (const QIcon & other )
QIcon &	operator= (QIcon && other )

静态公共成员

QStringList	fallbackSearchPaths ()
QString	fallbackThemeName ()
QIcon	fromTheme (const QString & name )
QIcon	fromTheme (const QString & name , const QIcon & fallback )
`(从 6.7 起)` QIcon	fromTheme (QIcon::ThemeIcon icon )
`(从 6.7 起)` QIcon	fromTheme (QIcon::ThemeIcon icon , const QIcon & fallback )
bool	hasThemeIcon (const QString & name )
`(从 6.7 起)` bool	hasThemeIcon (QIcon::ThemeIcon icon )
void	setFallbackSearchPaths (const QStringList & paths )
void	setFallbackThemeName (const QString & name )
void	setThemeName (const QString & name )
void	setThemeSearchPaths (const QStringList & paths )
QString	themeName ()
QStringList	themeSearchPaths ()

QDataStream &	operator<< (QDataStream & stream , const QIcon & icon )
QDataStream &	operator>> (QDataStream & stream , QIcon & icon )

详细描述

A QIcon can generate smaller, larger, active, and disabled pixmaps from the set of pixmaps it is given. Such pixmaps are used by Qt UI components to show an icon representing a particular action.

Creating an icon from image files

The simplest way to construct a QIcon is to create one from one or several image files or resources. For example:

QToolButton *button = new QToolButton;
button->setIcon(QIcon("open.png"));

QIcon can store several images for different states, and Qt will select the image that is the closest match for the action's current state.

QIcon openIcon("open.png");
openIcon.addFile("open-disabled.png", QIcon::Disabled);

Qt will generate the required icon styles and sizes when needed, e.g. the pixmap for the QIcon::Disabled state might be generated by graying out one of the provided pixmaps.

To clear the icon, simply set a null icon in its place:

button->setIcon(QIcon());

使用 QImageReader::supportedImageFormats () 和 QImageWriter::supportedImageFormats () 函数能检索支持文件格式的完整列表。

Creating an icon from a theme or icon library

The most convenient way to construct an icon is by using the fromTheme () factory function. Qt implements access to the native icon library on platforms that support the Freedesktop Icon Theme Specification . Since Qt 6.7, Qt also provides access to the native icon library on macOS, iOS, and Windows 10 and 11. On Android, Qt can access icons from the Material design system as long as the MaterialIcons-Regular font is available on the system, or bundled as a resource at :/qt-project.org/icons/MaterialIcons-Regular.ttf with the application.

QIcon undoicon = QIcon::fromTheme(QIcon::ThemeIcon::EditUndo);

Applications can use the same theming specification to provide their own icon library. See below for an example theme description and the corresponding directory structure for the image files. Icons from an application-provided theme take precedence over the native icon library.

In addition, it is possible to provide custom icon engines . This allows applications to customize every aspect of generated icons. With QIconEnginePlugin it is possible to register different icon engines for different file suffixes, making it possible for third parties to provide additional icon engines to those included with Qt.

制作使用 QIcon 的类

If you write your own widgets that have an option to set a small pixmap, consider allowing a QIcon to be set for that pixmap. The Qt class QToolButton is an example of such a widget.

Provide a method to set a QIcon, and paint the QIcon with paint , choosing the appropriate parameters based on the current state of your widget. For example:

void MyWidget::drawIcon(QPainter *painter, const QRect &rect)
{
    icon.paint(painter, rect, Qt::AlignCenter, isEnabled() ? QIcon::Normal
                                                           : QIcon::Disabled,
                                               isChecked() ? QIcon::On
                                                           : QIcon::Off);
}

当检索像素图使用 pixmap( QSize , Mode, State), and no pixmap for this given size, mode and state has been added with addFile () 或 addPixmap (), then QIcon will generate one on the fly. This pixmap generation happens in a QIconEngine . The default engine scales pixmaps down if required, but never up, and it uses the current style to calculate a disabled appearance.

You might also make use of the Active mode, perhaps making your widget Active when the mouse is over the widget (see QWidget::enterEvent ()), while the mouse is pressed pending the release that will activate the function, or when it is the currently selected item. If the widget can be toggled, the "On" mode might be used to draw a different icon.

注意： QIcon 需要 QGuiApplication 实例在创建图标之前。

高 DPI 图标

Icons that are provided by the native icon library are usually based on vector graphics, and will automatically be rendered in the appropriate resolution.

When providing your own image files via addFile (), then QIcon will use Qt's "@nx" high DPI syntax . This is useful if you have your own custom directory structure and do not use follow Freedesktop Icon Theme Specification .

When providing an application theme, then you need to follow the Icon Theme Specification to specify which files to use for different resolutions. To make QIcon use the high DPI version of an image, add an additional entry to the appropriate index.theme 文件：

[Icon Theme]
Name=Test
Comment=Test Theme
Directories=32x32/actions,32x32@2/actions
[32x32/actions]
Size=32
Context=Actions
Type=Fixed
# High DPI version of the entry above.
[32x32@2/actions]
Size=32
Scale=2
Type=Fixed

Your icon theme directory would then look something like this:

├── 32x32
│   └── actions
│       └── appointment-new.png
├── 32x32@2
│   └── actions
│       └── appointment-new.png
└── index.theme

成员类型文档编制

enum QIcon:: 模式

此枚举类型描述旨在使用的像素图模式。目前定义的模式：

常量	值	描述
`QIcon::Normal`	`0`	显示像素图当用户未与图标交互时，但由图标表示的功能是可用的。
`QIcon::Disabled`	`1`	Display the pixmap when the functionality represented by the icon is not available.
`QIcon::Active`	`2`	Display the pixmap when the functionality represented by the icon is available and the user is interacting with the icon, for example, moving the mouse over it or clicking it.
`QIcon::Selected`	`3`	显示像素图当由图标表示的项被选中时。

enum QIcon:: State

此枚举描述旨在使用的像素图状态。 state 可以是：

常量	值	描述
`QIcon::Off`	`1`	Display the pixmap when the widget is in an "off" state
`QIcon::On`	`0`	Display the pixmap when the widget is in an "on" state

`[since 6.7]` enum class QIcon:: ThemeIcon

This enum provides access to icons that are provided by most icon theme implementations.

常量	值	描述
`QIcon::ThemeIcon::AddressBookNew`	`0`	The icon for the action to create a new address book.
`QIcon::ThemeIcon::ApplicationExit`	`1`	The icon for exiting an application.
`QIcon::ThemeIcon::AppointmentNew`	`2`	The icon for the action to create a new appointment.
`QIcon::ThemeIcon::CallStart`	`3`	The icon for initiating or accepting a call.
`QIcon::ThemeIcon::CallStop`	`4`	The icon for stopping a current call.
`QIcon::ThemeIcon::ContactNew`	`5`	The icon for the action to create a new contact.
`QIcon::ThemeIcon::DocumentNew`	`6`	The icon for the action to create a new document.
`QIcon::ThemeIcon::DocumentOpen`	`7`	The icon for the action to open a document.
`QIcon::ThemeIcon::DocumentOpenRecent`	`8`	The icon for the action to open a document that was recently opened.
`QIcon::ThemeIcon::DocumentPageSetup`	`9`	The icon for the page setup action.
`QIcon::ThemeIcon::DocumentPrint`	`10`	The icon for the print action.
`QIcon::ThemeIcon::DocumentPrintPreview`	`11`	The icon for the print preview action.
`QIcon::ThemeIcon::DocumentProperties`	`12`	The icon for the action to view the properties of a document.
`QIcon::ThemeIcon::DocumentRevert`	`13`	The icon for the action of reverting to a previous version of a document.
`QIcon::ThemeIcon::DocumentSave`	`14`	The icon for the save action.
`QIcon::ThemeIcon::DocumentSaveAs`	`15`	The icon for the save as action.
`QIcon::ThemeIcon::DocumentSend`	`16`	The icon for the send action.
`QIcon::ThemeIcon::EditClear`	`17`	The icon for the clear action.
`QIcon::ThemeIcon::EditCopy`	`18`	The icon for the copy action.
`QIcon::ThemeIcon::EditCut`	`19`	The icon for the cut action.
`QIcon::ThemeIcon::EditDelete`	`20`	The icon for the delete action.
`QIcon::ThemeIcon::EditFind`	`21`	The icon for the find action.
`QIcon::ThemeIcon::EditPaste`	`22`	The icon for the paste action.
`QIcon::ThemeIcon::EditRedo`	`23`	The icon for the redo action.
`QIcon::ThemeIcon::EditSelectAll`	`24`	The icon for the select all action.
`QIcon::ThemeIcon::EditUndo`	`25`	The icon for the undo action.
`QIcon::ThemeIcon::FolderNew`	`26`	The icon for creating a new folder.
`QIcon::ThemeIcon::FormatIndentLess`	`27`	The icon for the decrease indent formatting action.
`QIcon::ThemeIcon::FormatIndentMore`	`28`	The icon for the increase indent formatting action.
`QIcon::ThemeIcon::FormatJustifyCenter`	`29`	The icon for the center justification formatting action.
`QIcon::ThemeIcon::FormatJustifyFill`	`30`	The icon for the fill justification formatting action.
`QIcon::ThemeIcon::FormatJustifyLeft`	`31`	The icon for the left justification formatting action.
`QIcon::ThemeIcon::FormatJustifyRight`	`32`	The icon for the right justification action.
`QIcon::ThemeIcon::FormatTextDirectionLtr`	`33`	The icon for the left-to-right text formatting action.
`QIcon::ThemeIcon::FormatTextDirectionRtl`	`34`	The icon for the right-to-left formatting action.
`QIcon::ThemeIcon::FormatTextBold`	`35`	The icon for the bold text formatting action.
`QIcon::ThemeIcon::FormatTextItalic`	`36`	The icon for the italic text formatting action.
`QIcon::ThemeIcon::FormatTextUnderline`	`37`	The icon for the underlined text formatting action.
`QIcon::ThemeIcon::FormatTextStrikethrough`	`38`	The icon for the strikethrough text formatting action.
`QIcon::ThemeIcon::GoDown`	`39`	The icon for the go down in a list action.
`QIcon::ThemeIcon::GoHome`	`40`	The icon for the go to home location action.
`QIcon::ThemeIcon::GoNext`	`41`	The icon for the go to the next item in a list action.
`QIcon::ThemeIcon::GoPrevious`	`42`	The icon for the go to the previous item in a list action.
`QIcon::ThemeIcon::GoUp`	`43`	The icon for the go up in a list action.
`QIcon::ThemeIcon::HelpAbout`	`44`	The icon for the 关于 item in the Help menu.
`QIcon::ThemeIcon::HelpFaq`	`45`	The icon for the FAQ item in the Help menu.
`QIcon::ThemeIcon::InsertImage`	`46`	The icon for the insert image action of an application.
`QIcon::ThemeIcon::InsertLink`	`47`	The icon for the insert link action of an application.
`QIcon::ThemeIcon::InsertText`	`48`	The icon for the insert text action of an application.
`QIcon::ThemeIcon::ListAdd`	`49`	The icon for the add to list action.
`QIcon::ThemeIcon::ListRemove`	`50`	The icon for the remove from list action.
`QIcon::ThemeIcon::MailForward`	`51`	The icon for the forward action.
`QIcon::ThemeIcon::MailMarkImportant`	`52`	The icon for the mark as important action.
`QIcon::ThemeIcon::MailMarkRead`	`53`	The icon for the mark as read action.
`QIcon::ThemeIcon::MailMarkUnread`	`54`	The icon for the mark as unread action.
`QIcon::ThemeIcon::MailMessageNew`	`55`	The icon for the compose new mail action.
`QIcon::ThemeIcon::MailReplyAll`	`56`	The icon for the reply to all action.
`QIcon::ThemeIcon::MailReplySender`	`57`	The icon for the reply to sender action.
`QIcon::ThemeIcon::MailSend`	`58`	The icon for the send action.
`QIcon::ThemeIcon::MediaEject`	`59`	The icon for the eject action of a media player or file manager.
`QIcon::ThemeIcon::MediaPlaybackPause`	`60`	The icon for the pause action of a media player.
`QIcon::ThemeIcon::MediaPlaybackStart`	`61`	The icon for the start playback action of a media player.
`QIcon::ThemeIcon::MediaPlaybackStop`	`62`	The icon for the stop action of a media player.
`QIcon::ThemeIcon::MediaRecord`	`63`	The icon for the record action of a media application.
`QIcon::ThemeIcon::MediaSeekBackward`	`64`	The icon for the seek backward action of a media player.
`QIcon::ThemeIcon::MediaSeekForward`	`65`	The icon for the seek forward action of a media player.
`QIcon::ThemeIcon::MediaSkipBackward`	`66`	The icon for the skip backward action of a media player.
`QIcon::ThemeIcon::MediaSkipForward`	`67`	The icon for the skip forward action of a media player.
`QIcon::ThemeIcon::ObjectRotateLeft`	`68`	The icon for the rotate left action performed on an object.
`QIcon::ThemeIcon::ObjectRotateRight`	`69`	The icon for the rotate right action performed on an object.
`QIcon::ThemeIcon::ProcessStop`	`70`	The icon for the stop action in applications with actions that may take a while to process, such as web page loading in a browser.
`QIcon::ThemeIcon::SystemLockScreen`	`71`	The icon for the lock screen action.
`QIcon::ThemeIcon::SystemLogOut`	`72`	The icon for the log out action.
`QIcon::ThemeIcon::SystemSearch`	`73`	The icon for the search action.
`QIcon::ThemeIcon::SystemReboot`	`74`	The icon for the reboot action.
`QIcon::ThemeIcon::SystemShutdown`	`75`	The icon for the shutdown action.
`QIcon::ThemeIcon::ToolsCheckSpelling`	`76`	The icon for the check spelling action.
`QIcon::ThemeIcon::ViewFullscreen`	`77`	The icon for the fullscreen action.
`QIcon::ThemeIcon::ViewRefresh`	`78`	The icon for the refresh action.
`QIcon::ThemeIcon::ViewRestore`	`79`	The icon for leaving the fullscreen view.
`QIcon::ThemeIcon::WindowClose`	`80`	The icon for the close window action.
`QIcon::ThemeIcon::WindowNew`	`81`	The icon for the new window action.
`QIcon::ThemeIcon::ZoomFitBest`	`82`	The icon for the best fit action.
`QIcon::ThemeIcon::ZoomIn`	`83`	The icon for the zoom in action.
`QIcon::ThemeIcon::ZoomOut`	`84`	The icon for the zoom out action.
`QIcon::ThemeIcon::AudioCard`	`85`	The icon for the audio rendering device.
`QIcon::ThemeIcon::AudioInputMicrophone`	`86`	The icon for the microphone audio input device.
`QIcon::ThemeIcon::Battery`	`87`	The icon for the system battery device.
`QIcon::ThemeIcon::CameraPhoto`	`88`	The icon for a digital still camera devices.
`QIcon::ThemeIcon::CameraVideo`	`89`	The icon for a video camera device.
`QIcon::ThemeIcon::CameraWeb`	`90`	The icon for a web camera device.
`QIcon::ThemeIcon::Computer`	`91`	The icon for the computing device as a whole.
`QIcon::ThemeIcon::DriveHarddisk`	`92`	The icon for hard disk drives.
`QIcon::ThemeIcon::DriveOptical`	`93`	The icon for optical media drives such as CD and DVD.
`QIcon::ThemeIcon::InputGaming`	`94`	The icon for the gaming input device.
`QIcon::ThemeIcon::InputKeyboard`	`95`	The icon for the keyboard input device.
`QIcon::ThemeIcon::InputMouse`	`96`	The icon for the mousing input device.
`QIcon::ThemeIcon::InputTablet`	`97`	The icon for graphics tablet input devices.
`QIcon::ThemeIcon::MediaFlash`	`98`	The icon for flash media, such as a memory stick.
`QIcon::ThemeIcon::MediaOptical`	`99`	The icon for physical optical media such as CD and DVD.
`QIcon::ThemeIcon::MediaTape`	`100`	The icon for generic physical tape media.
`QIcon::ThemeIcon::MultimediaPlayer`	`101`	The icon for generic multimedia playing devices.
`QIcon::ThemeIcon::NetworkWired`	`102`	The icon for wired network connections.
`QIcon::ThemeIcon::NetworkWireless`	`103`	The icon for wireless network connections.
`QIcon::ThemeIcon::Phone`	`104`	The icon for phone devices.
`QIcon::ThemeIcon::Printer`	`105`	The icon for a printer device.
`QIcon::ThemeIcon::Scanner`	`106`	The icon for a scanner device.
`QIcon::ThemeIcon::VideoDisplay`	`107`	The icon for the monitor that video gets displayed on.
`QIcon::ThemeIcon::AppointmentMissed`	`108`	The icon for when an appointment was missed.
`QIcon::ThemeIcon::AppointmentSoon`	`109`	The icon for when an appointment will occur soon.
`QIcon::ThemeIcon::AudioVolumeHigh`	`110`	The icon used to indicate high audio volume.
`QIcon::ThemeIcon::AudioVolumeLow`	`111`	The icon used to indicate low audio volume.
`QIcon::ThemeIcon::AudioVolumeMedium`	`112`	The icon used to indicate medium audio volume.
`QIcon::ThemeIcon::AudioVolumeMuted`	`113`	The icon used to indicate the muted state for audio playback.
`QIcon::ThemeIcon::BatteryCaution`	`114`	The icon used when the battery is below 40%.
`QIcon::ThemeIcon::BatteryLow`	`115`	The icon used when the battery is below 20%.
`QIcon::ThemeIcon::DialogError`	`116`	The icon used when a dialog is opened to explain an error condition to the user.
`QIcon::ThemeIcon::DialogInformation`	`117`	The icon used when a dialog is opened to give information to the user that may be pertinent to the requested action.
`QIcon::ThemeIcon::DialogPassword`	`118`	The icon used when a dialog requesting the authentication credentials for a user is opened.
`QIcon::ThemeIcon::DialogQuestion`	`119`	The icon used when a dialog is opened to ask a simple question to the user.
`QIcon::ThemeIcon::DialogWarning`	`120`	The icon used when a dialog is opened to warn the user of impending issues with the requested action.
`QIcon::ThemeIcon::FolderDragAccept`	`121`	The icon used for a folder while an acceptable object is being dragged onto it.
`QIcon::ThemeIcon::FolderOpen`	`122`	The icon used for folders, while their contents are being displayed within the same window.
`QIcon::ThemeIcon::FolderVisiting`	`123`	The icon used for folders, while their contents are being displayed in another window.
`QIcon::ThemeIcon::ImageLoading`	`124`	The icon used while another image is being loaded.
`QIcon::ThemeIcon::ImageMissing`	`125`	The icon used when another image could not be loaded.
`QIcon::ThemeIcon::MailAttachment`	`126`	The icon for a message that contains attachments.
`QIcon::ThemeIcon::MailUnread`	`127`	The icon for an unread message.
`QIcon::ThemeIcon::MailRead`	`128`	The icon for a read message.
`QIcon::ThemeIcon::MailReplied`	`129`	The icon for a message that has been replied to.
`QIcon::ThemeIcon::MediaPlaylistRepeat`	`130`	The icon for the repeat mode of a media player.
`QIcon::ThemeIcon::MediaPlaylistShuffle`	`131`	The icon for the shuffle mode of a media player.
`QIcon::ThemeIcon::NetworkOffline`	`132`	The icon used to indicate that the device is not connected to the network.
`QIcon::ThemeIcon::PrinterPrinting`	`133`	The icon used while a print job is successfully being spooled to a printing device.
`QIcon::ThemeIcon::SecurityHigh`	`134`	The icon used to indicate that the security level of an item is known to be high.
`QIcon::ThemeIcon::SecurityLow`	`135`	The icon used to indicate that the security level of an item is known to be low.
`QIcon::ThemeIcon::SoftwareUpdateAvailable`	`136`	The icon used to indicate that an update is available.
`QIcon::ThemeIcon::SoftwareUpdateUrgent`	`137`	The icon used to indicate that an urgent update is available.
`QIcon::ThemeIcon::SyncError`	`138`	The icon used when an error occurs while attempting to synchronize data across devices.
`QIcon::ThemeIcon::SyncSynchronizing`	`139`	The icon used while data is successfully synchronizing across devices.
`QIcon::ThemeIcon::UserAvailable`	`140`	The icon used to indicate that a user is available.
`QIcon::ThemeIcon::UserOffline`	`141`	The icon used to indicate that a user is not available.
`QIcon::ThemeIcon::WeatherClear`	`142`	The icon used to indicate that the sky is clear.
`QIcon::ThemeIcon::WeatherClearNight`	`143`	The icon used to indicate that the sky is clear during the night.
`QIcon::ThemeIcon::WeatherFewClouds`	`144`	The icon used to indicate that the sky is partly cloudy.
`QIcon::ThemeIcon::WeatherFewCloudsNight`	`145`	The icon used to indicate that the sky is partly cloudy during the night.
`QIcon::ThemeIcon::WeatherFog`	`146`	The icon used to indicate that the weather is foggy.
`QIcon::ThemeIcon::WeatherShowers`	`147`	The icon used to indicate that rain showers are occurring.
`QIcon::ThemeIcon::WeatherSnow`	`148`	The icon used to indicate that snow is falling.
`QIcon::ThemeIcon::WeatherStorm`	`149`	The icon used to indicate that the weather is stormy.

该枚举在 Qt 6.7 引入。

另请参阅 QIcon#Creating an icon from a theme or icon library and fromTheme ().

成员函数文档编制

`[static, since 6.7]` QIcon QIcon:: fromTheme ( QIcon::ThemeIcon icon )

`[static, since 6.7]` QIcon QIcon:: fromTheme ( QIcon::ThemeIcon icon , const QIcon & fallback )

这是重载函数。

返回 QIcon 对应 icon 在 current icon theme .

If the current theme does not provide an icon for icon ， fallback icon theme is consulted, before falling back to looking up standalone icon files in the fallback icon search path . Finally, the platform's native icon library is consulted.

If no icon is found and a fallback is provided, fallback is returned. This is useful to provide a guaranteed fallback, regardless of whether the current set of icon themes and fallbacks paths support the requested icon.

If no icon is found and no fallback is provided, a default constructed, empty QIcon 被返回。

该函数在 Qt 6.7 引入。

`[noexcept]` QIcon:: QIcon ()

构造 null 图标。

QIcon:: QIcon (const QPixmap & pixmap )

构造图标从 pixmap .

`[explicit]` QIcon:: QIcon (const QString & fileName )

构造图标从文件采用给定 fileName 。将按需加载文件。

若 fileName 包含相对路径 (如：仅文件名)，必须相对运行时工作目录查找相关文件。

文件名可以引用实际磁盘文件或应用程序嵌入资源之一。见资源系统概述，了解如何在应用程序可执行文件中嵌入图像及其它资源文件的细节。

使用 QImageReader::supportedImageFormats () 和 QImageWriter::supportedImageFormats () 函数能检索支持文件格式的完整列表。

`[explicit]` QIcon:: QIcon ( QIconEngine * engine )

创建图标采用特定图标 engine 。图标拥有引擎的所有权。

QIcon:: QIcon (const QIcon & other )

构造副本为 other 。这非常快。

`[noexcept]` QIcon:: QIcon ( QIcon && other )

移动构造 QIcon 实例，使它指向同一对象 other 所指向的。

`[noexcept]` QIcon:: ~QIcon ()

销毁图标。

QSize QIcon:: actualSize (const QSize & size , QIcon::Mode mode = Normal, QIcon::State state = Off) const

Returns the actual size of the icon for the requested size , mode ，和 state . The result might be smaller than requested, but never larger. The returned size is in device-independent pixels (This is relevant for high-dpi pixmaps.)

另请参阅 pixmap () 和 paint ().

void QIcon:: addFile (const QString & fileName , const QSize & size = QSize(), QIcon::Mode mode = Normal, QIcon::State state = Off)

Adds an image from the file with the given fileName 到图标，作为特殊化为 size , mode and state . The file will be loaded on demand. Note: custom icon engines are free to ignore additionally added pixmaps.

若 fileName 包含相对路径 (如：仅文件名)，必须相对运行时工作目录查找相关文件。

文件名可以引用实际磁盘文件或应用程序嵌入资源之一。见资源系统概述，了解如何在应用程序可执行文件中嵌入图像及其它资源文件的细节。

使用 QImageReader::supportedImageFormats () 和 QImageWriter::supportedImageFormats () 函数能检索支持文件格式的完整列表。

If a high resolution version of the image exists (identified by the suffix @2x on the base name), it is automatically loaded and added with the 设备像素比率 set to a value of 2. This can be disabled by setting the environment variable QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING (见 QImageReader ).

注意： When you add a non-empty filename to a QIcon , the icon becomes non-null, even if the file doesn't exist or points to a corrupt file.

另请参阅 addPixmap () 和 QPixmap::devicePixelRatio ().

void QIcon:: addPixmap (const QPixmap & pixmap , QIcon::Mode mode = Normal, QIcon::State state = Off)

添加 pixmap 到图标，作为特殊化为 mode and state .

自定义图标引擎可自由忽略额外添加的像素图。

另请参阅 addFile ().

QList < QSize > QIcon:: availableSizes ( QIcon::Mode mode = Normal, QIcon::State state = Off) const

返回可用图标大小的列表为指定 mode and state .

qint64 QIcon:: cacheKey () const

返回的数字标识内容对于此 QIcon 对象。截然不同的 QIcon objects can have the same key if they refer to the same contents.

The cacheKey() will change when the icon is altered via addPixmap () 或 addFile ().

Cache keys are mostly useful in conjunction with caching.

另请参阅 QPixmap::cacheKey ().

`[static]` QStringList QIcon:: fallbackSearchPaths ()

返回用于图标的回退搜索路径。

The fallback search paths are consulted for standalone icon files if the current icon theme or fallback icon theme do not provide results for an icon lookup.

If not set, the fallback search paths will be defined by the platform.

另请参阅 setFallbackSearchPaths () 和 themeSearchPaths ().

`[static]` QString QIcon:: fallbackThemeName ()

返回回退图标主题的名称。

If not set, the fallback icon theme will be defined by the platform.

注意： Platform fallback icon themes are only implemented on Freedesktop based systems at the moment, and the icon theme depends on your desktop settings.

另请参阅 setFallbackThemeName () 和 themeName ().

`[static]` QIcon QIcon:: fromTheme (const QString & name )

返回 QIcon 对应 name 在 current icon theme .

If the current theme does not provide an icon for name ， fallback icon theme is consulted, before falling back to looking up standalone icon files in the fallback icon search path . Finally, the platform's native icon library is consulted.

To fetch an icon from the current icon theme:

QIcon undoicon = QIcon::fromTheme(QIcon::ThemeIcon::EditUndo);

If an icon theme has not been explicitly set via setThemeName () a platform defined icon theme will be used.

另请参阅 themeName (), fallbackThemeName (), setThemeName (), themeSearchPaths (), fallbackSearchPaths ()，和 Freedesktop Icon Naming Specification .

`[static]` QIcon QIcon:: fromTheme (const QString & name , const QIcon & fallback )

这是重载函数。

返回 QIcon 对应 name 在 current icon theme .

If no icon is found fallback 被返回。

This is useful to provide a guaranteed fallback, regardless of whether the current set of icon themes and fallbacks paths support the requested icon.

例如：

QIcon undoicon = QIcon::fromTheme(QIcon::ThemeIcon::EditUndo, QIcon(":/undo.png"));

另请参阅 fallbackThemeName () 和 fallbackSearchPaths ().

`[static]` bool QIcon:: hasThemeIcon (const QString & name )

返回 true if there is an icon available for name in the current icon theme or any of the fallbacks, as described by fromTheme (），否则返回 false .

另请参阅 themeSearchPaths (), fromTheme ()，和 setThemeName ().

`[static, since 6.7]` bool QIcon:: hasThemeIcon ( QIcon::ThemeIcon icon )

这是重载函数。

返回 true if there is an icon available for icon in the current icon theme or any of the fallbacks, as described by fromTheme (），否则返回 false .

该函数在 Qt 6.7 引入。

另请参阅 fromTheme ().

bool QIcon:: isMask () const

返回 true if this icon has been marked as a mask image. Certain platforms render mask icons differently (for example, menu icons on macOS).

另请参阅 setIsMask ().

bool QIcon:: isNull () const

返回 true 若图标为空；否则返回 false .

图标为空，若既没有像素图也没有文件名。

注意：即使非 null 图标也可能无法创建有效像素图 (如若文件不存在，或无法读取)。

QString QIcon:: name () const

返回用于创建图标的名称，若可用。

从属图标的创建方式，它可能有关联名称。这是用于创建图标的情况采用 fromTheme ().

另请参阅 fromTheme () 和 QIconEngine::iconName ().

void QIcon:: paint ( QPainter * painter , const QRect & rect , Qt::Alignment alignment = Qt::AlignCenter, QIcon::Mode mode = Normal, QIcon::State state = Off) const

使用 painter 来描绘图标采用指定 alignment ，要求 mode ，和 state 到矩形 rect .

另请参阅 actualSize () 和 pixmap ().

void QIcon:: paint ( QPainter * painter , int x , int y , int w , int h , Qt::Alignment alignment = Qt::AlignCenter, QIcon::Mode mode = Normal, QIcon::State state = Off) const

这是重载函数。

将图标描绘到矩形 QRect ( x , y , w , h ).

QPixmap QIcon:: pixmap (const QSize & size , QIcon::Mode mode = Normal, QIcon::State state = Off) const

Returns a pixmap with the requested size , mode ，和 state , generating one if necessary. The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

另请参阅 actualSize () 和 paint ().

QPixmap QIcon:: pixmap ( int w , int h , QIcon::Mode mode = Normal, QIcon::State state = Off) const

这是重载函数。

Returns a pixmap of size QSize ( w , h ). The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

QPixmap QIcon:: pixmap ( int extent , QIcon::Mode mode = Normal, QIcon::State state = Off) const

这是重载函数。

Returns a pixmap of size QSize ( extent , extent ). The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

`[since 6.0]` QPixmap QIcon:: pixmap (const QSize & size , qreal devicePixelRatio , QIcon::Mode mode = Normal, QIcon::State state = Off) const

这是重载函数。

Returns a pixmap with the requested size , devicePixelRatio , mode ，和 state , generating one with the given mode and state if necessary. The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

该函数在 Qt 6.0 引入。

另请参阅 actualSize () 和 paint ().

`[static]` void QIcon:: setFallbackSearchPaths (const QStringList & paths )

Sets the fallback search paths for icons to paths .

The fallback search paths are consulted for standalone icon files if the current icon theme or fallback icon theme do not provide results for an icon lookup.

例如：

QIcon::setFallbackSearchPaths(QIcon::fallbackSearchPaths() << "my/search/path");

另请参阅 fallbackSearchPaths () 和 setThemeSearchPaths ().

`[static]` void QIcon:: setFallbackThemeName (const QString & name )

将回退图标主题设为 name .

The fallback icon theme is consulted for icons not provided by the current icon theme , or if the current icon theme does not exist.

The name should correspond to theme in the same format as documented by setThemeName (), and will be looked up in themeSearchPaths ().

注意： Fallback icon themes should be set before creating QGuiApplication , to ensure correct initialization.

另请参阅 fallbackThemeName (), themeSearchPaths ()，和 themeName ().

void QIcon:: setIsMask ( bool isMask )

Indicate that this icon is a mask image(boolean isMask ), and hence can potentially be modified based on where it's displayed.

另请参阅 isMask ().

`[static]` void QIcon:: setThemeName (const QString & name )

将当前图标主题设为 name .

The theme will be will be looked up in themeSearchPaths ().

At the moment the only supported icon theme format is the Freedesktop Icon Theme Specification 。 name should correspond to a directory name in the themeSearchPath() containing an index.theme file describing its contents.

另请参阅 themeSearchPaths (), themeName ()，和 Freedesktop Icon Theme Specification .

`[static]` void QIcon:: setThemeSearchPaths (const QStringList & paths )

Sets the search paths for icon themes to paths .

The content of paths should follow the theme format documented by setThemeName ().

另请参阅 themeSearchPaths (), fromTheme ()，和 setThemeName ().

`[noexcept]` void QIcon:: swap ( QIcon & other )

交换图标 other 与此图标。此操作非常快且从不失败。

`[static]` QString QIcon:: themeName ()

返回当前图标主题的名称。

If not set, the current icon theme will be defined by the platform.

注意： Platform icon themes are only implemented on Freedesktop based systems at the moment, and the icon theme depends on your desktop settings.

另请参阅 setThemeName (), themeSearchPaths (), fromTheme ()，和 hasThemeIcon ().

`[static]` QStringList QIcon:: themeSearchPaths ()

返回图标主题的搜索路径。

The default search paths will be defined by the platform. All platforms will also have the resource directory :\icons as a fallback.

另请参阅 setThemeSearchPaths (), fromTheme ()，和 setThemeName ().

QVariant QIcon:: operator QVariant () const

Returns the icon as a QVariant .

QIcon &QIcon:: operator= (const QIcon & other )

赋值 other 图标到此图标并返回此图标的引用。

`[noexcept]` QIcon &QIcon:: operator= ( QIcon && other )

移动赋值 other 到此 QIcon 实例。

QIcon 类

公共类型

公共函数

静态公共成员

相关非成员

详细描述

Creating an icon from image files

Creating an icon from a theme or icon library

制作使用 QIcon 的类

高 DPI 图标

成员类型文档编制

enum QIcon:: 模式

enum QIcon:: State

[since 6.7] enum class QIcon:: ThemeIcon

成员函数文档编制

[static, since 6.7] QIcon QIcon:: fromTheme ( QIcon::ThemeIcon icon )

[static, since 6.7] QIcon QIcon:: fromTheme ( QIcon::ThemeIcon icon , const QIcon & fallback )

[noexcept] QIcon:: QIcon ()

QIcon:: QIcon (const QPixmap & pixmap )

[explicit] QIcon:: QIcon (const QString & fileName )

[explicit] QIcon:: QIcon ( QIconEngine * engine )

QIcon:: QIcon (const QIcon & other )

[noexcept] QIcon:: QIcon ( QIcon && other )

[noexcept] QIcon:: ~QIcon ()

QSize QIcon:: actualSize (const QSize & size , QIcon::Mode mode = Normal, QIcon::State state = Off) const

void QIcon:: addFile (const QString & fileName , const QSize & size = QSize(), QIcon::Mode mode = Normal, QIcon::State state = Off)

void QIcon:: addPixmap (const QPixmap & pixmap , QIcon::Mode mode = Normal, QIcon::State state = Off)

QList < QSize > QIcon:: availableSizes ( QIcon::Mode mode = Normal, QIcon::State state = Off) const

qint64 QIcon:: cacheKey () const

[static] QStringList QIcon:: fallbackSearchPaths ()

[static] QString QIcon:: fallbackThemeName ()

[static] QIcon QIcon:: fromTheme (const QString & name )

[static] QIcon QIcon:: fromTheme (const QString & name , const QIcon & fallback )

[static] bool QIcon:: hasThemeIcon (const QString & name )

[static, since 6.7] bool QIcon:: hasThemeIcon ( QIcon::ThemeIcon icon )

bool QIcon:: isMask () const

bool QIcon:: isNull () const

QString QIcon:: name () const

void QIcon:: paint ( QPainter * painter , const QRect & rect , Qt::Alignment alignment = Qt::AlignCenter, QIcon::Mode mode = Normal, QIcon::State state = Off) const

void QIcon:: paint ( QPainter * painter , int x , int y , int w , int h , Qt::Alignment alignment = Qt::AlignCenter, QIcon::Mode mode = Normal, QIcon::State state = Off) const

QPixmap QIcon:: pixmap (const QSize & size , QIcon::Mode mode = Normal, QIcon::State state = Off) const

QPixmap QIcon:: pixmap ( int w , int h , QIcon::Mode mode = Normal, QIcon::State state = Off) const

QPixmap QIcon:: pixmap ( int extent , QIcon::Mode mode = Normal, QIcon::State state = Off) const

[since 6.0] QPixmap QIcon:: pixmap (const QSize & size , qreal devicePixelRatio , QIcon::Mode mode = Normal, QIcon::State state = Off) const

[static] void QIcon:: setFallbackSearchPaths (const QStringList & paths )

[static] void QIcon:: setFallbackThemeName (const QString & name )

void QIcon:: setIsMask ( bool isMask )

[static] void QIcon:: setThemeName (const QString & name )

[static] void QIcon:: setThemeSearchPaths (const QStringList & paths )

[noexcept] void QIcon:: swap ( QIcon & other )

[static] QString QIcon:: themeName ()

[static] QStringList QIcon:: themeSearchPaths ()

QVariant QIcon:: operator QVariant () const

QIcon &QIcon:: operator= (const QIcon & other )

[noexcept] QIcon &QIcon:: operator= ( QIcon && other )

相关非成员

QDataStream & operator<< ( QDataStream & stream , const QIcon & icon )

QDataStream & operator>> ( QDataStream & stream , QIcon & icon )

内容

`[since 6.7]` enum class QIcon:: ThemeIcon

`[static, since 6.7]` QIcon QIcon:: fromTheme ( QIcon::ThemeIcon icon )

`[static, since 6.7]` QIcon QIcon:: fromTheme ( QIcon::ThemeIcon icon , const QIcon & fallback )

`[noexcept]` QIcon:: QIcon ()

`[explicit]` QIcon:: QIcon (const QString & fileName )

`[explicit]` QIcon:: QIcon ( QIconEngine * engine )

`[noexcept]` QIcon:: QIcon ( QIcon && other )

`[noexcept]` QIcon:: ~QIcon ()

`[static]` QStringList QIcon:: fallbackSearchPaths ()

`[static]` QString QIcon:: fallbackThemeName ()

`[static]` QIcon QIcon:: fromTheme (const QString & name )

`[static]` QIcon QIcon:: fromTheme (const QString & name , const QIcon & fallback )

`[static]` bool QIcon:: hasThemeIcon (const QString & name )

`[static, since 6.7]` bool QIcon:: hasThemeIcon ( QIcon::ThemeIcon icon )

`[since 6.0]` QPixmap QIcon:: pixmap (const QSize & size , qreal devicePixelRatio , QIcon::Mode mode = Normal, QIcon::State state = Off) const

`[static]` void QIcon:: setFallbackSearchPaths (const QStringList & paths )

`[static]` void QIcon:: setFallbackThemeName (const QString & name )

`[static]` void QIcon:: setThemeName (const QString & name )

`[static]` void QIcon:: setThemeSearchPaths (const QStringList & paths )

`[noexcept]` void QIcon:: swap ( QIcon & other )

`[static]` QString QIcon:: themeName ()

`[static]` QStringList QIcon:: themeSearchPaths ()

`[noexcept]` QIcon &QIcon:: operator= ( QIcon && other )