QJsonObject 类

QJsonObject 类封装 JSON 对象。 更多...

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

注意: 此类的所有函数 可重入 .

公共类型

class const_iterator
class iterator
ConstIterator
Iterator
key_type
mapped_type
size_type

公共函数

QJsonObject ()
QJsonObject (std::initializer_list<std::pair<QString, QJsonValue>> args )
QJsonObject (const QJsonObject & other )
QJsonObject (QJsonObject && other )
~QJsonObject ()
QJsonObject::iterator begin ()
QJsonObject::const_iterator begin () const
QJsonObject::const_iterator constBegin () const
QJsonObject::const_iterator constEnd () const
QJsonObject::const_iterator constFind (const QString & key ) const
QJsonObject::const_iterator constFind (QStringView key ) const
QJsonObject::const_iterator constFind (QLatin1StringView key ) const
bool contains (const QString & key ) const
bool contains (QStringView key ) const
bool contains (QLatin1StringView key ) const
qsizetype count () const
bool empty () const
QJsonObject::iterator end ()
QJsonObject::const_iterator end () const
QJsonObject::iterator erase (QJsonObject::iterator it )
QJsonObject::iterator find (const QString & key )
QJsonObject::const_iterator find (const QString & key ) const
QJsonObject::iterator find (QStringView key )
QJsonObject::iterator find (QLatin1StringView key )
QJsonObject::const_iterator find (QStringView key ) const
QJsonObject::const_iterator find (QLatin1StringView key ) const
QJsonObject::iterator insert (const QString & key , const QJsonValue & value )
QJsonObject::iterator insert (QStringView key , const QJsonValue & value )
QJsonObject::iterator insert (QLatin1StringView key , const QJsonValue & value )
bool isEmpty () const
QStringList keys () const
qsizetype length () const
void remove (const QString & key )
void remove (QStringView key )
void remove (QLatin1StringView key )
qsizetype size () const
void swap (QJsonObject & other )
QJsonValue take (const QString & key )
QJsonValue take (QStringView key )
QJsonValue take (QLatin1StringView key )
QVariantHash toVariantHash () const
QVariantMap toVariantMap () const
QJsonValue value (const QString & key ) const
QJsonValue value (QStringView key ) const
QJsonValue value (QLatin1StringView key ) const
bool operator!= (const QJsonObject & other ) const
QJsonObject & operator= (const QJsonObject & other )
QJsonObject & operator= (QJsonObject && other )
bool operator== (const QJsonObject & other ) const
QJsonValue operator[] (const QString & key ) const
QJsonValueRef operator[] (const QString & key )
QJsonValue operator[] (QStringView key ) const
QJsonValue operator[] (QLatin1StringView key ) const
QJsonValueRef operator[] (QStringView key )
QJsonValueRef operator[] (QLatin1StringView key )

静态公共成员

QJsonObject fromVariantHash (const QVariantHash & hash )
QJsonObject fromVariantMap (const QVariantMap & map )

详细描述

A JSON object is a list of key value pairs, where the keys are unique strings and the values are represented by a QJsonValue .

A QJsonObject can be converted to and from a QVariantMap . You can query the number of (key, value) pairs with size (), insert (),和 remove () entries from it and iterate over its content using the standard C++ iterator pattern.

QJsonObject is an implicitly shared class, and shares the data with the document it has been created from as long as it is not being modified.

You can convert the object to and from text based JSON through QJsonDocument .

另请参阅 在 Qt 中支持 JSON and 保存和加载游戏 .

成员类型文档编制

QJsonObject:: ConstIterator

Qt 样式同义词 QJsonObject::const_iterator .

QJsonObject:: Iterator

Qt 样式同义词 QJsonObject::iterator .

QJsonObject:: key_type

typedef 对于 QString . Provided for STL compatibility.

QJsonObject:: mapped_type

typedef 对于 QJsonValue . Provided for STL compatibility.

QJsonObject:: size_type

Typedef for qsizetype. Provided for STL compatibility.

成员函数文档编制

QJsonObject:: QJsonObject ()

构造空的 JSON 对象。

另请参阅 isEmpty ().

QJsonObject:: QJsonObject ( std::initializer_list < std::pair < QString , QJsonValue >> args )

Constructs a QJsonObject instance initialized from args initialization list. For example:

QJsonObject object
{
    {"property1", 1},
    {"property2", 2}
};
					

[noexcept] QJsonObject:: QJsonObject (const QJsonObject & other )

创建副本为 other .

Since QJsonObject is implicitly shared, the copy is shallow as long as the object does not get modified.

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

移动构造 QJsonObject,从 other .

[noexcept] QJsonObject:: ~QJsonObject ()

销毁对象。

QJsonObject::iterator QJsonObject:: begin ()

返回 STL 样式迭代器 pointing to the first item in the object.

另请参阅 constBegin () 和 end ().

QJsonObject::const_iterator QJsonObject:: begin () const

这是重载函数。

QJsonObject::const_iterator QJsonObject:: constBegin () const

返回常量 STL 样式迭代器 pointing to the first item in the object.

另请参阅 begin () 和 constEnd ().

QJsonObject::const_iterator QJsonObject:: constEnd () const

返回常量 STL 样式迭代器 pointing to the imaginary item after the last item in the object.

另请参阅 constBegin () 和 end ().

QJsonObject::const_iterator QJsonObject:: constFind (const QString & key ) const

Returns a const iterator pointing to the item with key key in the map.

If the map contains no item with key key ,函数返回 constEnd ().

QJsonObject::const_iterator QJsonObject:: constFind ( QStringView key ) const

这是重载函数。

QJsonObject::const_iterator QJsonObject:: constFind ( QLatin1StringView key ) const

这是重载函数。

bool QJsonObject:: contains (const QString & key ) const

返回 true if the object contains key key .

另请参阅 insert (), remove (),和 take ().

bool QJsonObject:: contains ( QStringView key ) const

这是重载函数。

bool QJsonObject:: contains ( QLatin1StringView key ) const

这是重载函数。

qsizetype QJsonObject:: count () const

这是重载函数。

如同 size ().

bool QJsonObject:: empty () const

此函数为兼容 STL (标准模板库) 提供。它相当于 isEmpty (), returning true if the object is empty; otherwise returning false .

QJsonObject::iterator QJsonObject:: end ()

返回 STL 样式迭代器 pointing to the imaginary item after the last item in the object.

另请参阅 begin () 和 constEnd ().

QJsonObject::const_iterator QJsonObject:: end () const

这是重载函数。

QJsonObject::iterator QJsonObject:: erase ( QJsonObject::iterator it )

Removes the (key, value) pair pointed to by the iterator it from the map, and returns an iterator to the next item in the map.

另请参阅 remove ().

QJsonObject::iterator QJsonObject:: find (const QString & key )

Returns an iterator pointing to the item with key key in the map.

If the map contains no item with key key ,函数返回 end ().

QJsonObject::const_iterator QJsonObject:: find (const QString & key ) const

这是重载函数。

QJsonObject::iterator QJsonObject:: find ( QStringView key )

这是重载函数。

QJsonObject::iterator QJsonObject:: find ( QLatin1StringView key )

这是重载函数。

QJsonObject::const_iterator QJsonObject:: find ( QStringView key ) const

这是重载函数。

QJsonObject::const_iterator QJsonObject:: find ( QLatin1StringView key ) const

这是重载函数。

[static] QJsonObject QJsonObject:: fromVariantHash (const QVariantHash & hash )

Converts the variant hash hash QJsonObject .

The keys in hash will be used as the keys in the JSON object, and the QVariant values will be converted to JSON values.

注意: Conversion from QVariant is not completely lossless. Please see the documentation in QJsonValue::fromVariant () 了解更多信息。

另请参阅 fromVariantMap (), toVariantHash (),和 QJsonValue::fromVariant ().

[static] QJsonObject QJsonObject:: fromVariantMap (const QVariantMap & map )

Converts the variant map map QJsonObject .

The keys in map will be used as the keys in the JSON object, and the QVariant values will be converted to JSON values.

注意: Conversion from QVariant is not completely lossless. Please see the documentation in QJsonValue::fromVariant () 了解更多信息。

另请参阅 fromVariantHash (), toVariantMap (),和 QJsonValue::fromVariant ().

QJsonObject::iterator QJsonObject:: insert (const QString & key , const QJsonValue & value )

Inserts a new item with the key key 和值 value .

If there is already an item with the key key , then that item's value is replaced with value .

Returns an iterator pointing to the inserted item.

If the value is QJsonValue::Undefined , it will cause the key to get removed from the object. The returned iterator will then point to end ().

另请参阅 remove (), take (), QJsonObject::iterator ,和 end ().

QJsonObject::iterator QJsonObject:: insert ( QStringView key , const QJsonValue & value )

这是重载函数。

QJsonObject::iterator QJsonObject:: insert ( QLatin1StringView key , const QJsonValue & value )

这是重载函数。

bool QJsonObject:: isEmpty () const

返回 true if the object is empty. This is the same as size () == 0.

另请参阅 size ().

QStringList QJsonObject:: keys () const

返回在此对象中的所有键列表。

The list is sorted alphabetically.

qsizetype QJsonObject:: length () const

这是重载函数。

如同 size ().

void QJsonObject:: remove (const QString & key )

移除 key 从对象。

另请参阅 insert () 和 take ().

void QJsonObject:: remove ( QStringView key )

这是重载函数。

void QJsonObject:: remove ( QLatin1StringView key )

这是重载函数。

qsizetype QJsonObject:: size () const

Returns the number of (key, value) pairs stored in the object.

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

Swaps the object other with this. This operation is very fast and never fails.

QJsonValue QJsonObject:: take (const QString & key )

移除 key 从对象。

返回 QJsonValue containing the value referenced by key 。若 key was not contained in the object, the returned QJsonValue is QJsonValue::Undefined .

另请参阅 insert (), remove (),和 QJsonValue .

QJsonValue QJsonObject:: take ( QStringView key )

这是重载函数。

QJsonValue QJsonObject:: take ( QLatin1StringView key )

这是重载函数。

QVariantHash QJsonObject:: toVariantHash () const

把此对象转换成 QVariantHash .

返回创建的哈希。

另请参阅 toVariantMap ().

QVariantMap QJsonObject:: toVariantMap () const

把此对象转换成 QVariantMap .

返回创建的映射。

另请参阅 toVariantHash ().

QJsonValue QJsonObject:: value (const QString & key ) const

返回 QJsonValue 表示值为键 key .

返回的 QJsonValue is QJsonValue::Undefined 若键不存在。

另请参阅 QJsonValue and QJsonValue::isUndefined ().

QJsonValue QJsonObject:: value ( QStringView key ) const

这是重载函数。

QJsonValue QJsonObject:: value ( QLatin1StringView key ) const

这是重载函数。

bool QJsonObject:: operator!= (const QJsonObject & other ) const

返回 true if other is not equal to this object.

[noexcept] QJsonObject &QJsonObject:: operator= (const QJsonObject & other )

赋值 other 到此对象。

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

移动赋值 other 到此对象。

bool QJsonObject:: operator== (const QJsonObject & other ) const

返回 true if other is equal to this object.

QJsonValue QJsonObject:: operator[] (const QString & key ) const

返回 QJsonValue 表示值为键 key .

This does the same as value ().

返回的 QJsonValue is QJsonValue::Undefined 若键不存在。

另请参阅 value (), QJsonValue ,和 QJsonValue::isUndefined ().

QJsonValueRef QJsonObject:: operator[] (const QString & key )

Returns a reference to the value for key . If there is no value with key key in the object, one is created with a QJsonValue::Null value and then returned.

The return value is of type QJsonValueRef , a helper class for QJsonArray and QJsonObject . When you get an object of type QJsonValueRef , you can use it as if it were a reference to a QJsonValue . If you assign to it, the assignment will apply to the element in the QJsonArray or QJsonObject from which you got the reference.

另请参阅 value ().

QJsonValue QJsonObject:: operator[] ( QStringView key ) const

这是重载函数。

QJsonValue QJsonObject:: operator[] ( QLatin1StringView key ) const

这是重载函数。

QJsonValueRef QJsonObject:: operator[] ( QStringView key )

这是重载函数。

QJsonValueRef QJsonObject:: operator[] ( QLatin1StringView key )

这是重载函数。