A topic command tells QDoc which source code element is being documented. Some topic commands allow you to create documentation pages that aren't tied to any underlying source code element.
When QDoc processes a QDoc comment, it tries to connect the comment to an element in the source code by first looking for a topic command that names the source code element. If there is no topic command, QDoc tries to connect the comment to the source code element that immediately follows the comment. If it can't do either of these and if there is no topic command that indicates the comment does not have an underlying source code element (e.g. \page ), then the comment is discarded.
The name of the entity being documented is usually the only argument for a topic command. Use the complete name. Sometimes there can be a second parameter in the argument. See e.g. \page .
\enum QComboBox::InsertPolicy
\fn command is a special case. For the \fn command, use the function's signature including the class qualifier.
\fn void QGraphicsWidget::setWindowFlags(Qt::WindowFlags wFlags)
A topic command can appear anywhere in a comment but must stand alone on its own line. It is good practice is to let the topic command be the first line of the comment. If the argument spans several lines, make sure that each line (except the last one) is ended with a backslash. Moreover, QDoc counts parentheses, which means that if it encounters a '(' it considers everything until the closing ')' as its argument.
If a topic command is repeated with different arguments, the same documentation will appear for both the units.
/ *! \fn void PreviewWindow::setWindowFlags() \fn void ControllerWindow::setWindowFlags() Sets the widgets flags using the QWidget::setWindowFlags() function. Then runs through the available window flags, creating a text that contains the names of the flags that matches the flags parameter, displaying the text in the widgets text editor. * /
PreviewWindow::setWindowFlags()
and
ControllerWindow::setWindowFlags()
functions will get the same documentation.
The \class command is for documenting a C++ class. The argument is the complete name of the class. The command tells QDoc that a class is part of the public API, and lets you enter a detailed description.
/ *! \class QMap::iterator \brief The QMap::iterator class provides an STL-style non-const iterator for QMap and QMultiMap. QMap features both \l{STL-style iterators} and \l{Java-style iterators}. The STL-style iterators ... * /
The HTML documentation for the named class is written to a
.html
file named from the class name, in lower case, and with the double colon qualifier(s) replaced with '-'. For example, the documentation for the
QMap::Iterator
class is written to
qmap-iterator.html
.
The file contains the class description from the \class comment, plus the documentation generated from QDoc comments for all the class members: a list of the class's types, properties, functions, signals, and slots.
In addition to the detailed description of the class, the \class comment typically contains a \brief command and one or more 标记命令 . See the \class command for any of the Qt class for examples. Here is a very simple example:
/ *! \class PreviewWindow \brief The PreviewWindow class is a custom widget. displaying the names of its currently set window flags in a read-only text editor. \ingroup miscellaneous The PreviewWindow class inherits QWidget. The widget displays the names of its window flags set with the \l {function} {setWindowFlags()} function. It is also provided with a QPushButton that closes the window. ... \sa QWidget * /
The way QDoc renders this \class will depend a lot on your
style.css
file, but the general outline of the class reference page will look like this:
The PreviewWindow class is a custom widget displaying the names of its currently set window flags in a read-only text editor. 更多...
The PreviewWindow class is a custom widget displaying the names of its currently set window flags in a read-only text editor.
The PreviewWindow class inherits QWidget . The widget displays the names of its window flags set with the setWindowFlags() function. It is also provided with a QPushButton that closes the window.
...
另请参阅 QWidget .
Constructs a preview window widget with parent .
Sets the widgets flags using the QWidget::setWindowFlags () 函数。
Then runs through the available window flags, creating a text that contains the names of the flags that matches the flags parameter, displaying the text in the widgets text editor.
The \enum command is for documenting a C++ enum type. The argument is the full name of the enum type.
The enum values are documented in the \enum comment using the
\value
command. If an enum value is not documented with \value, QDoc emits a warning. These warnings can be avoided using the
\omitvalue
command to tell QDoc that an enum value should not be documented. The enum documentation will be included on the class reference page, header file page, or namespace page where the enum type is defined. For example, consider the enum type
Corner
in the Qt namespace:
enum Corner { TopLeftCorner = 0x00000, TopRightCorner = 0x00001, BottomLeftCorner = 0x00002, BottomRightCorner = 0x00003 #if defined(QT3_SUPPORT) && !defined(Q_MOC_RUN) ,TopLeft = TopLeftCorner, TopRight = TopRightCorner, BottomLeft = BottomLeftCorner, BottomRight = BottomRightCorner #endif };
This enum can be cocumented this way:
/ *! \enum Qt::Corner This enum type specifies a corner in a rectangle: \value TopLeftCorner The top-left corner of the rectangle. \value TopRightCorner The top-right corner of the rectangle. \value BottomLeftCorner The bottom-left corner of the rectangle. \value BottomRightCorner The bottom-right corner of the rectangle. \omitvalue TopLeft \omitvalue TopRight \omitvalue BottomLeft \omitvalue BottomRight Bottom-right (omitted; not documented). * /
Note the inclusion of the namespace qualifier. QDoc will render this enum type in
qt.html
像这样：
此枚举类型指定矩形角落：
| 常量 | 值 | 描述 |
|---|---|---|
| Qt::TopLeftCorner | 0x00000 | 矩形左上角。 |
| Qt::TopRightCorner | 0x00001 | 矩形的右上角。 |
| Qt::BottomLeftCorner | 0x00002 | 矩形的左下角。 |
| Qt::BottomRightCorner | 0x00003 | 矩形的右下角。 |
另请参阅 \value and \omitvalue .
The \example command is for documenting an example. The argument is the example's path relative to one of the paths listed in the exampledirs variable in the QDoc configuration file.
The documentation page will be output to
modulename-path-to-example
.html. QDoc will add a list of all the example's source and images files at the end of the page, unless
\noautolist
command is used or the configuration variable
url.examples
is defined for the project.
例如，若
exampledirs
包含
$QTDIR/examples/widgets/imageviewer
，那么
/ *! \example widgets/imageviewer \title ImageViewer Example \subtitle The example shows how to combine QLabel and QScrollArea to display an image. ... * /
QDoc renders this example in widgets-imageviewer.html:
范例展示如何组合 QLabel and QScrollArea 以显示图像。
文件：
...
另请参阅： \generatelist examplefiles , \noautolist , url.examples , \meta
The \externalpage command assigns a title to an external URL.
/ *! \externalpage http://doc.qt.io/ \title Qt Documentation Site * /
This allows you to include a link to the external page in your documentation this way:
/ *! At the \l {Qt Documentation Site} you can find the latest documentation for Qt, Qt Creator, the Qt SDK and much more. * /
QDoc renders this as:
At the Qt Documentation Site you can find the latest documentation for Qt, Qt Creator, the Qt SDK and much more.
To achieve the same result without using the \externalpage command, you would have to hard-code the address into your documentation:
/ *! At the \l {http://doc.qt.io/}{Qt Documentation Site} you can find the latest documentation for Qt, Qt Creator, the Qt SDK and much more. * /
The \externalpage command makes it easier to maintain the documentation. If the address changes, you only need to change the argument of the \externalpage command.
The \fn command is for documenting a function. The argument is the function's signature, including its template parameters (if any), return type, const-ness, and list of formal arguments with types. If the named function doesn't exist, QDoc emits a warning.
Since QDoc version 6.0, the \fn command can be used for documenting class members that are not explicitly declared in the header, but are implicitly generated by the compiler; default constructor and destructor, copy constructor and move-copy constructor, assignment operator, and move-assignment operator.
注意：
The \fn command is QDoc's default command: when no topic command can be found in a QDoc comment, QDoc tries to tie the documentation to the following code as if it is the documentation for a function. Hence, it is normally not necessary to include this command when documenting a function, if the function's QDoc comment is written immediately above the function implementation in the
.cpp
file. But it must be present when documenting an inline function in the
.cpp
file that is implemented in the
.h
文件。
/ *! \fn bool QToolBar::isAreaAllowed(Qt::ToolBarArea area) const Returns \c true if this toolbar is dockable in the given \a area; otherwise returns \c false. * /
QDoc renders this as:
返回
true
若此工具栏可停放在给定
area
；否则返回
false
.
注意：
Running in debug mode (pass the
-debug
command line option or set the
QDOC_DEBUG
environment variable before invoking QDoc) can help troubleshoot \fn commands that QDoc fails to parse. In debug mode, additional diagnostic information is available.
另请参阅 \overload .
The \group command creates a separate page that lists the classes belonging to the group. The argument is the group name.
A class is included in a group by using the \ingroup command. Overview pages can also be related to a group using the same command, but the list of overview pages must be requested explicitly using the \generatelist command (see example below).
The \group command is typically followed by a
\title
command and a short introduction to the group. The HTML page for the group is written to a
.html
file put in <lower-case>
group
.html.
Each class name is listed as a link to the class reference page followed by the text from the class's \brief texts.
/ *! \group io \title Input/Output and Networking These classes are used to handle input and output to and from external devices, processes, files etc., as well as manipulating files and directories. * /
QDoc generates a group page in
io.html
that will look like this:
These classes are used to handle input and output to and from external devices, processes, files etc., as well as manipulating files and directories.
| QAbstractSocket | 所有套接字类型共有的基本功能 |
| QBuffer | QByteArray 的 QIODevice 接口 |
| QClipboard | 访问窗口系统剪贴板 |
Note that overview pages related to the group, must be listed explicitly using the
\generatelist
command with the
related
自变量。
/ *! \group architecture \title Architecture These documents describe aspects of Qt's architecture and design, including overviews of core Qt features and technologies. \generatelist{related} * /
另请参阅 \ingroup and \generatelist .
The \headerfile command is for documenting the global functions, types and macros that are declared in a header file, but not in a namespace. The argument is the name of the header file. The HTML page is written to a
.html
file constructed from the header file argument.
The documentation for a function, type, or macro that is declared in the header file being documented, is included in the header file page using the \relates 命令。
If the argument doesn't exist as a header file, the \headerfile command creates a documentation page for the header file anyway.
/ *! \headerfile <QtAlgorithms> \title Generic Algorithms \brief The <QtAlgorithms> header file provides generic template-based algorithms. Qt provides a number of global template functions in \c <QtAlgorithms> that work on containers and perform well-know algorithms. * /
QDoc generates a header file page
qtalgorithms.html
that looks like this:
Qt provides a number of global template functions in
<QtAlgorithms>
that work on containers and perform well-know algorithms.
...
另请参阅 \inheaderfile .
The \macro command is for documenting a C++ macro. The argument is the macro in one of three styles: function-like macros like Q_ASSERT (), declaration-style macros like Q_PROPERTY (), and macros without parentheses like Q_OBJECT .
The \macro comment must contain a
\relates
command that attaches the macro comment to a class, header file, or namespace. Otherwise, the documentation will be lost. Here are three example macro comments followed by what they might look like in
qtglobal.html
or
qobject.html
:
/ *! \macro void Q_ASSERT(bool test) \relates <QtGlobal> Prints a warning message containing the source code file name and line number if \a test is false. ... \sa Q_ASSERT_X(), qFatal(), {Debugging Techniques} * /
Prints a warning message containing the source code file name and line number if test 为 false。
...
另请参阅 Q_ASSERT_X (), qFatal () 和 调试技术 .
/ *! \macro Q_PROPERTY(...) \relates QObject This macro declares a QObject property. The syntax is: ... \sa {Qt's Property System} * /
This macro declares a QObject property. The syntax is:
...
另请参阅 Qt 的特性系统 .
/ *! \macro Q_OBJECT \relates QObject The Q_OBJECT macro must appear in the private section of a class definition that declares its own signals and slots, or that uses other services provided by Qt's meta-object system. ... \sa {Meta-Object System}, {Signals and Slots}, {Qt's Property System} * /
Q_OBJECT macro must appear in the private section of a class definition that declares its own signals and slots or that uses other services provided by Qt's meta-object system.
...
另请参阅 元对象系统 , 信号 & 槽 and Qt 的特性系统 .
The \module creates a page that lists the classes belonging to the module specified by the command's argument. A class included in the module by including the \inmodule command in the \class comment.
The \module command is typically followed by a \title 和 \brief command. Each class is listed as a link to the class reference page followed by the text from the class's \brief command. For example:
/ *! \module QtNetwork \title Qt Network Module \brief Contains classes for writing TCP/IP clients and servers. The network module provides classes to make network programming easier and portable. It offers both high-level classes such as QNetworkAccessManager that implements application-level protocols, and lower-level classes such as QTcpSocket, QTcpServer, and QUdpSocket. * /
QDoc renders this in
qtnetwork.html
像这样：
The Qt Network module offers classes that allow you to write TCP/IP clients and servers. 更多...
| QAbstractSocket | 所有套接字类型共有的基本功能 |
| ... | ... |
The Qt Network module offers classes that allow you to write TCP/IP clients and servers.
The network module provides classes to make network programming easier and portable. It offers both high-level classes such as QNetworkAccessManager that implements application-level protocols, and lower-level classes such as QTcpSocket, QTcpServer, and QUdpSocket.
...
\noautolist command can be used here to omit the automatically generated list of classes at the end.
另请参阅 \inmodule
The \namespace command is for documenting the contents of the C++ namespace named as its argument. The reference page QDoc generates for a namespace is similar to the reference page it generates for a C++ class.
/ *! \namespace Qt \brief Contains miscellaneous identifiers used throughout the Qt library. * /
QDoc renders this in
qt.html
像这样：
Qt 名称空间包含整个 Qt 库所用的杂项标识符。 更多...
#include <Qt>
Contains miscellaneous identifiers used throughout the Qt library.
...
Note that in C++, a particular namespace can be used in more than one module, but when C++ elements from different modules are declared in the same namespace, the namespace itself must be documented in one module only. For example, namespace Qt in the example above contains types and functions from both QtCore and QtGui , but it is documented with the \namespace command only in QtCore .
The \page command is for creating a stand-alone documentation page. The argument can consist of two parts separated by a space. The first part is the name of the file where QDoc should store the page. The second part, if present, is a word that specifies the page type. Currently, the second part can be one of the following list of words:
The page title is set using the \title 命令。
/ *! \page aboutqt.html \title About Qt Qt is a C++ toolkit for cross-platform GUI application development. Qt provides single-source portability across Microsoft Windows, macOS, Linux, and all major commercial Unix variants. Qt provides application developers with all the functionality needed to build applications with state-of-the-art graphical user interfaces. Qt is fully object-oriented, easily extensible, and allows true component programming. ... * /
QDoc renders this page in
aboutqt.html
.
The \property command is for documenting a Qt property. The argument is the full property name.
A property is defined using the Q_PROPERTY () macro. The macro takes as arguments the property's name and its set, reset and get functions.
Q_PROPERTY(QString state READ state WRITE setState)
The set, reset and get functions don't need to be documented, documenting the property is sufficient. QDoc will generate a list of the access function that will appear in the property documentation which in turn will be located in the documentation of the class that defines the property.
The \property command comment typically includes a \brief command. For properties the \brief command's argument is a sentence fragment that will be included in a one line description of the property. The command follows the same rules for the description 作为 \variable 命令。
/ *! \property QPushButton::flat \brief Whether the border is disabled. This property's default is false. * /
QDoc includes this in
qpushbutton.html
像这样：
This property holds whether the border is disabled.
此特性默认为 false。
访问函数：
/ *! \property QWidget::width \brief The width of the widget excluding any window frame. See the \l {Window Geometry} documentation for an overview of window geometry. \sa geometry, height, size * /
QDoc includes this in
qwidget.html
像这样：
This property holds the width of the widget excluding any window frame.
见 窗口几何体 documentation for an overview of window geometry.
访问函数：
另请参阅 geometry , height ，和 size .
The \qmlattachedproperty command is for documenting a QML property that will be attached to some QML type. See
附加特性
. The argument is the rest of the line. The argument text should be the property type, followed by the QML element name where the property is being declared, the
::
qualifier, and finally the property name. If we have a QML attached property named
isCurrentItem
in QML
ListView
, and the property has type
bool
, the \qmlattachedproperty for it would look like this:
/ *! \qmlattachedproperty bool ListView::isCurrentItem This attached property is \c true if this delegate is the current item; otherwise false. It is attached to each instance of the delegate. This property may be used to adjust the appearance of the current item, for example: \snippet doc/src/snippets/declarative/listview/listview.qml isCurrentItem * /
QDoc includes this attached property on the QML reference page for the ListView 元素。
The \qmlattachedsignal command is for documenting an attachable signal . The \qmlattachedsignal command is used just like the \qmlsignal 命令。
The argument is the rest of the line. It should be the name of the QML type where the signal is declared, the
::
qualifier, and finally the signal name. For example, a QML attached signal named
add()
在
GridView
element is documented like this:
/ *! \qmlattachedsignal GridView::add() This attached signal is emitted immediately after an item is added to the view. * /
QDoc includes this documentation on the QML reference page for the GridView 元素。
The \qmlbasictype command is for documenting a basic type for QML. The argument is the type name. The type must be included in the QML basic types group using the \ingroup command as shown below. This will cause QDoc to include the documentation for the type on the QML 基本类型 page. The \brief command is also required, because it appears on the QML 基本类型 page as well.
/ *! \qmlbasictype int \ingroup qmlbasictypes \brief An integer is a whole number, for example 0, 10, or -20. An integer is a whole number, e.g. 0, 10, or -20. The possible \c int values range from around -2000000000 to around 2000000000, although most elements will only accept a reduced range (which they mention in their documentation). 范例： \qml Item { width: 100; height: 200 } \endqml \sa {QML Basic Types} * /
QDoc outputs this as qml-int.html .
This command is deprecated. Use \qmltype 代替。
The \qmlclass command is for documenting a QML type that is instantiated by a C++ class. The command has two arguments. The first argument is the name of the QML type. The second argument is the name of the C++ class that instantiates the QML type.
/ *! \qmlclass Transform QGraphicsTransform \ingroup qml-transform-elements \since 4.7 \brief Provides a way of building advanced transformations on Items. The Transform element is a base type which cannot be instantiated directly. The following concrete Transform types are available: \list \li \l Rotation \li \l Scale \li \l Translate \endlist The Transform elements let you create and control advanced transformations that can be configured independently using specialized properties. You can assign any number of Transform elements to an \l Item. Each Transform is applied in order, one at a time. * /
This example generates the QML Transform page. The \qmlclass comment should include the \since command, because all QML types are new. It should also include the \brief command. If a type is a member of a group of QML types, it should also include one or more \ingroup 命令。
The \qmlmethod command is for documenting a QML method. The argument is the complete method signature, including return type and parameter names and types.
/ *! \qmlmethod void TextInput::select(int start, int end) Causes the text from \a start to \a end to be selected. If either start or end is out of range, the selection is not changed. After having called this, selectionStart will become the lesser, and selectionEnd the greater (regardless of the order passed to this method). \sa selectionStart, selectionEnd * /
QDoc includes this documentation on the element reference page for the TextInput 元素。
The \qmltype command is for documenting a QML type. The command has one argument, which is the name of the QML type.
If the QML type is instantiated by a C++ class, that class must be specified using the \instantiates context command.
/ *! \qmltype Transform \instantiates QGraphicsTransform \inqmlmodule QtQuick \brief Provides a way to build advanced transformations on Items. The Transform element is a base type which cannot be instantiated directly. * /
在这里， \qmltype comment includes \instantiates to specify that a Transform is instantiated by the C++ class QGraphicsTransform . A \qmltype comment should always include a \since command, because all QML types are new. It should also include a \brief description. If a QML type is a member of a QML type group, the \qmltype comment should include one or more \ingroup 命令。
The \qmlproperty command is for documenting a QML property. The argument is the rest of the line. The argument text should be the property type, followed by the QML type name, the
::
qualifier, and finally the property name. If we have a QML property named
x
in QML type
Translate
, and the property has type
real
, the \qmlproperty for it would look like this:
/ *! \qmlproperty real Translate::x The translation along the X axis. * /
QDoc includes this QML property on the QML reference page for the Translate 元素。
If the QML property is of enumeration type, or it holds a bit-wise combination of flags, the \value command can be used to document the acceptable values.
The \qmlsignal command is for documenting a QML signal. The argument is the rest of the line. The arguments should be: the QML type where the signal is declared, the
::
qualifier, and finally the signal name. If we have a QML signal named
clicked()
, the documentation for it would look like this:
/ *! \qmlsignal QtQuick::MouseArea::clicked(MouseEvent mouse) This signal is emitted when there is a click. A click is defined as a press followed by a release, both inside the MouseArea. * /
QDoc includes this documentation on the QML reference page for the MouseArea 元素。
使用
\\qmlmodule
command to create a
QML
module page. A QML module page is a collection of QML types or any related material. The command takes an optional
<VERSION>
number argument, and is similar to the
group-command
.
A QML class can be associated with a module by adding the
\inqmlmodule
command to the comment-block that documents the class. You can link to any member of a QML module using the module name and two colons (
::
) prefix.
\beginqdoc
A link to the TabWidget of the UI Component is \l {UIComponent::TabWidget}.
\endqdoc
QDoc generates a page for the module that lists all the members of the module.
\qmlmodule ClickableComponents This is a list of the Clickable Components set. A Clickable component responds to a \c clicked() event.
A QML class may belong to a
QML 模块
by inserting the
\inqmlmodule
command as a topic command, with the module name (without a version number) as the only argument. Every member of a group must be linked to using the module name and two colons (
::
).
\qmltype ClickableButton
\inqmlmodule ClickableComponents
A clickable button that responds to the \c click() event.
To link to the
ClickableButton
，使用
\l ClickableComponents::ClickableButton
格式。
\noautolist command can be used here to omit the automatically generated list of types at the end.
The \instantiates command is used in the QML 类型 comment of an elemental QML type to specify the name of the C++ class that instantiates the QML type.
If the QML type is not instantiated by a C++ class, this command is not used.
/ *! \qmltype Transform \instantiates QGraphicsTransform \inqmlmodule QtQuick \brief Provides a way to build advanced transformations on Items. The Transform element is a base type which cannot be instantiated directly. * /
在这里， \qmltype comment includes \instantiates to specify that a Transform is instantiated by the C++ class QGraphicsTransform .
The \typealias command is similar to \typedef , but specific to documenting a C++ type alias:
class Foo { public: using ptr = void*; // ... }
This can be documented as
/*!
\typealias Foo::ptr
*/
QDoc will automatically generate a sentence in the documentation describing the alias:
This is a type alias for
void*
.
The \typealias command was introduced in QDoc 5.15.
另请参阅 \typedef .
The \typedef command is for documenting a C++ typedef. The argument is the name of the typedef. The documentation for the typedef will be included in the reference documentation for the class, namespace, or header file in which the typedef is declared. To relate the \typedef to a class, namespace, or header file, the \typedef comment must contain a \relates 命令。
/ *! \typedef QObjectList \relates QObject Synonym for QList<QObject>. * /
QDoc includes this in
qobject.html
as:
Another, although more rare, example:
/ *! \typedef QMsgHandler \relates QtGlobal This is a typedef for a pointer to a function with the following signature: \code void myMsgHandler(QtMsgType, const char *); \ endcode \sa QtMsgType, qInstallMessageHandler() * /
QDoc includes this in
qtglobal.html
as:
这是采用以下签名的函数指针的 typedef：
void myMsgHandler(QtMsgType, const char *);
另请参阅 QtMsgType and qInstallMessageHandler ().
Other typedefs are located on the reference page for the class that defines them.
/ *! \typedef QList::Iterator Qt-style synonym for QList::iterator. * /
QDoc includes this one on the reference page for class QList as:
Qt 样式同义词 QList::iterator .
另请参阅 \typealias .
The \variable command is for documenting a class member variable or a constant. The argument is the variable or constant name. The \variable command comment includes a \brief command. QDoc generates the documentation based on the text from \brief command.
The documentation will be located in the in the associated class, header file, or namespace documentation.
In case of a member variable:
/ *! \variable QStyleOption::palette \brief The palette that should be used when painting the control * /
QDoc includes this in qstyleoption.html as:
This variable holds the palette that should be used when painting the control.
You can also document constants with the \variable command. For example, suppose you have the
类型
and
UserType
constants in the
QTreeWidgetItem
类：
enum { Type = 0, UserType = 1000 };
For these, the \variable command can be used this way:
/ *! \variable QTreeWidgetItem::Type The default type for tree widget items. \sa UserType, type() * /
/ *! \variable QTreeWidgetItem::UserType The minimum value for custom types. Values below UserType are reserved by Qt. \sa Type, type() * /
QDoc includes these in qtreewidget.html as:
用于树 Widget 项的默认类型。
用于自定义类型的最小值。低于 UserType 的值由 Qt 预留。