QJsonArray 类

QJsonArray 类封装 JSON 数组。 更多...

头: #include <QJsonArray>
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
const_pointer
const_reference
difference_type
pointer
reference
size_type
value_type

公共函数

QJsonArray ()
QJsonArray (std::initializer_list<QJsonValue> args )
QJsonArray (const QJsonArray & other )
QJsonArray (QJsonArray && other )
~QJsonArray ()
void append (const QJsonValue & value )
QJsonValue at (qsizetype i ) const
QJsonArray::iterator begin ()
QJsonArray::const_iterator begin () const
QJsonArray::const_iterator cbegin () const
QJsonArray::const_iterator cend () const
QJsonArray::const_iterator constBegin () const
QJsonArray::const_iterator constEnd () const
bool contains (const QJsonValue & value ) const
qsizetype count () const
bool empty () const
QJsonArray::iterator end ()
QJsonArray::const_iterator end () const
QJsonArray::iterator erase (QJsonArray::iterator it )
QJsonValue first () const
void insert (qsizetype i , const QJsonValue & value )
QJsonArray::iterator insert (QJsonArray::iterator before , const QJsonValue & value )
bool isEmpty () const
QJsonValue last () const
void pop_back ()
void pop_front ()
void prepend (const QJsonValue & value )
void push_back (const QJsonValue & value )
void push_front (const QJsonValue & value )
void removeAt (qsizetype i )
void removeFirst ()
void removeLast ()
void replace (qsizetype i , const QJsonValue & value )
qsizetype size () const
void swap (QJsonArray & other )
QJsonValue takeAt (qsizetype i )
QVariantList toVariantList () const
bool operator!= (const QJsonArray & other ) const
QJsonArray operator+ (const QJsonValue & value ) const
QJsonArray & operator+= (const QJsonValue & value )
QJsonArray & operator<< (const QJsonValue & value )
QJsonArray & operator= (const QJsonArray & other )
QJsonArray & operator= (QJsonArray && other )
bool operator== (const QJsonArray & other ) const
QJsonValueRef operator[] (qsizetype i )
QJsonValue operator[] (qsizetype i ) const

静态公共成员

QJsonArray fromStringList (const QStringList & list )
QJsonArray fromVariantList (const QVariantList & list )

详细描述

A JSON array is a list of values. The list can be manipulated by inserting and removing QJsonValue 's from the array.

A QJsonArray can be converted to and from a QVariantList . You can query the number of entries with size (), insert (),和 removeAt () entries from it and iterate over its content using the standard C++ iterator pattern.

QJsonArray 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 array 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

QJsonArray:: ConstIterator

Qt 样式同义词 QJsonArray::const_iterator .

QJsonArray:: Iterator

Qt 样式同义词 QJsonArray::iterator .

QJsonArray:: const_pointer

Typedef for const QJsonValue *. Provided for STL compatibility.

QJsonArray:: const_reference

Typedef for const QJsonValue &. Provided for STL compatibility.

QJsonArray:: difference_type

Typedef for qsizetype. Provided for STL compatibility.

QJsonArray:: pointer

typedef 对于 QJsonValue *. Provided for STL compatibility.

QJsonArray:: reference

typedef 对于 QJsonValue &. Provided for STL compatibility.

QJsonArray:: size_type

Typedef for qsizetype. Provided for STL compatibility.

QJsonArray:: value_type

typedef 对于 QJsonValue . Provided for STL compatibility.

成员函数文档编制

QJsonArray:: QJsonArray ()

Creates an empty array.

QJsonArray:: QJsonArray ( std::initializer_list < QJsonValue > args )

Creates an array initialized from args initialization list.

QJsonArray can be constructed in a way similar to JSON notation, for example:

QJsonArray array = { 1, 2.2, QString() };
					

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

创建副本为 other .

Since QJsonArray is implicitly shared, the copy is shallow as long as the object doesn't get modified.

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

Move-constructs a QJsonArray from other .

[noexcept] QJsonArray:: ~QJsonArray ()

Deletes the array.

void QJsonArray:: append (const QJsonValue & value )

插入 value at the end of the array.

另请参阅 prepend () 和 insert ().

QJsonValue QJsonArray:: at ( qsizetype i ) const

返回 QJsonValue representing the value for index i .

返回的 QJsonValue is Undefined ,若 i is out of bounds.

QJsonArray::iterator QJsonArray:: begin ()

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

另请参阅 constBegin () 和 end ().

QJsonArray::const_iterator QJsonArray:: begin () const

这是重载函数。

QJsonArray::const_iterator QJsonArray:: cbegin () const

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

另请参阅 begin () 和 cend ().

QJsonArray::const_iterator QJsonArray:: cend () const

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

另请参阅 cbegin () 和 end ().

QJsonArray::const_iterator QJsonArray:: constBegin () const

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

另请参阅 begin () 和 constEnd ().

QJsonArray::const_iterator QJsonArray:: constEnd () const

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

另请参阅 constBegin () 和 end ().

bool QJsonArray:: contains (const QJsonValue & value ) const

返回 true if the array contains an occurrence of value , otherwise false .

另请参阅 count ().

qsizetype QJsonArray:: count () const

如同 size ().

另请参阅 size ().

bool QJsonArray:: empty () const

此函数为兼容 STL (标准模板库) 提供。它相当于 isEmpty () 并返回 true if the array is empty.

QJsonArray::iterator QJsonArray:: end ()

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

另请参阅 begin () 和 constEnd ().

QJsonArray::const_iterator QJsonArray:: end () const

这是重载函数。

QJsonArray::iterator QJsonArray:: erase ( QJsonArray::iterator it )

Removes the item pointed to by it , and returns an iterator pointing to the next item.

另请参阅 removeAt ().

QJsonValue QJsonArray:: first () const

Returns the first value stored in the array.

如同 at(0) .

另请参阅 at ().

[static] QJsonArray QJsonArray:: fromStringList (const QStringList & list )

Converts the string list list QJsonArray .

The values in list will be converted to JSON values.

另请参阅 toVariantList () 和 QJsonValue::fromVariant ().

[static] QJsonArray QJsonArray:: fromVariantList (const QVariantList & list )

Converts the variant list list QJsonArray .

The QVariant values in list 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 toVariantList () 和 QJsonValue::fromVariant ().

void QJsonArray:: insert ( qsizetype i , const QJsonValue & value )

插入 value at index position i in the array. If i is 0 , the value is prepended to the array. If i is size (), the value is appended to the array.

另请参阅 append (), prepend (), replace (),和 removeAt ().

QJsonArray::iterator QJsonArray:: insert ( QJsonArray::iterator before , const QJsonValue & value )

插入 value before the position pointed to by before , and returns an iterator pointing to the newly inserted item.

另请参阅 erase () 和 insert ().

bool QJsonArray:: isEmpty () const

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

另请参阅 size ().

QJsonValue QJsonArray:: last () const

Returns the last value stored in the array.

如同 at(size() - 1) .

另请参阅 at ().

void QJsonArray:: pop_back ()

此函数为兼容 STL (标准模板库) 提供。它相当于 removeLast (). The array must not be empty. If the array can be empty, call isEmpty () before calling this function.

void QJsonArray:: pop_front ()

此函数为兼容 STL (标准模板库) 提供。它相当于 removeFirst (). The array must not be empty. If the array can be empty, call isEmpty () before calling this function.

void QJsonArray:: prepend (const QJsonValue & value )

插入 value at the beginning of the array.

这如同 insert(0, value) and will prepend value to the array.

另请参阅 append () 和 insert ().

void QJsonArray:: push_back (const QJsonValue & value )

此函数为兼容 STL (标准模板库) 提供。它相当于 append (value) and will append value to the array.

void QJsonArray:: push_front (const QJsonValue & value )

此函数为兼容 STL (标准模板库) 提供。它相当于 prepend (value) and will prepend value to the array.

void QJsonArray:: removeAt ( qsizetype i )

Removes the value at index position i . i must be a valid index position in the array (i.e., 0 <= i < size() ).

另请参阅 insert () 和 replace ().

void QJsonArray:: removeFirst ()

Removes the first item in the array. Calling this function is equivalent to calling removeAt(0) . The array must not be empty. If the array can be empty, call isEmpty () before calling this function.

另请参阅 removeAt () 和 removeLast ().

void QJsonArray:: removeLast ()

Removes the last item in the array. Calling this function is equivalent to calling removeAt(size() - 1) . The array must not be empty. If the array can be empty, call isEmpty () before calling this function.

另请参阅 removeAt () 和 removeFirst ().

void QJsonArray:: replace ( qsizetype i , const QJsonValue & value )

替换项在索引位置 i with value . i must be a valid index position in the array (i.e., 0 <= i < size() ).

另请参阅 operator[] () 和 removeAt ().

qsizetype QJsonArray:: size () const

Returns the number of values stored in the array.

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

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

QJsonValue QJsonArray:: takeAt ( qsizetype i )

Removes the item at index position i and returns it. i must be a valid index position in the array (i.e., 0 <= i < size() ).

若不使用返回值, removeAt () 效率更高。

另请参阅 removeAt ().

QVariantList QJsonArray:: toVariantList () const

把此对象转换成 QVariantList .

返回创建的映射。

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

返回 true if this array is not equal to other .

QJsonArray QJsonArray:: operator+ (const QJsonValue & value ) const

Returns an array that contains all the items in this array followed by the provided value .

另请参阅 operator+= ().

QJsonArray &QJsonArray:: operator+= (const QJsonValue & value )

追加 value to the array, and returns a reference to the array itself.

另请参阅 append () 和 operator<< ().

QJsonArray &QJsonArray:: operator<< (const QJsonValue & value )

追加 value to the array, and returns a reference to the array itself.

另请参阅 operator+= () 和 append ().

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

赋值 other 到此数组。

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

移动赋值 other 到此数组。

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

返回 true if this array is equal to other .

QJsonValueRef QJsonArray:: operator[] ( qsizetype i )

Returns the value at index position i 作为可修改引用。 i must be a valid index position in the array (i.e., 0 <= i < size() ).

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 character in the QJsonArray of QJsonObject from which you got the reference.

另请参阅 at ().

QJsonValue QJsonArray:: operator[] ( qsizetype i ) const

这是重载函数。

如同 at ().