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#ifndef QBYTEARRAY_H
#define QBYTEARRAY_H#include <QtCore/qrefcount.h>
#include <QtCore/qnamespace.h>
#include <QtCore/qarraydata.h>
#include <QtCore/qarraydatapointer.h>
#include <QtCore/qcontainerfwd.h>
#include <QtCore/qbytearrayalgorithms.h>
#include <QtCore/qbytearrayview.h>#include <stdlib.h>
#include <string.h>
#include <stdarg.h>#include <string>
#include <iterator>#ifndef QT5_NULL_STRINGS
// Would ideally be off, but in practice breaks too much (Qt 6.0).
#define QT5_NULL_STRINGS 1
#endif#ifdef truncate
#error qbytearray.h must be included before any header file that defines truncate
#endif#if defined(Q_OS_DARWIN) || defined(Q_QDOC)
Q_FORWARD_DECLARE_CF_TYPE(CFData);
Q_FORWARD_DECLARE_OBJC_CLASS(NSData);
#endifQT_BEGIN_NAMESPACE //说明本类定义于 QT 的全局命名空间class QString;
class QDataStream;/*
struct QArrayData
{ QBasicAtomicInt ref_ ;ArrayOptions flags;qsizetype alloc;static void * allocate(...) noexcept;static void deallocate(...) noexcept;
};template <class T>
struct QTypedArrayData : QArrayData { }; //本类无数据成员template <class T>
struct QArrayDataPointer //上面的注释给出了学习与阅读本头文件的因缘
{Data * d ; //Data = QTypedArrayData<T> 包含了申请释放内存的成员方法T * ptr; //真正的堆区中的数据起点qsizetype size;
};class QString
{ typedef QTypedArrayData<char16_t> Data; //一个类型定义DataPointer d;//DataPointer = QStringPrivate = QArrayDataPointer<char16_t>;
}; 本注释用于解释本 QByteArray 类的数据结构的组成
*/using QByteArrayData = QArrayDataPointer<char>; //类型起别名，这似乎是个指针类型# define QByteArrayLiteral(str) \(QByteArray(QByteArrayData(nullptr, const_cast<char *>(str), sizeof(str) - 1))) \/**/class Q_CORE_EXPORT QByteArray //本类的真正的数据成员，就是一个指针
{
public:using DataPointer = QByteArrayData; //看起来是指针类型private:DataPointer d; //本类的数据成员，这是一个指针static const char _empty; //本类的静态数据成员typedef QTypedArrayData<char> Data; //概略定义在上面,这是类型定义，关于内存分配
public:enum Base64Option {Base64Encoding = 0,Base64UrlEncoding = 1,KeepTrailingEquals = 0,OmitTrailingEquals = 2,IgnoreBase64DecodingErrors = 0,AbortOnBase64DecodingErrors = 4,};Q_DECLARE_FLAGS(Base64Options, Base64Option)// Base64Options = QFlags<Base64Option>enum class Base64DecodingStatus {Ok,IllegalInputLength,IllegalCharacter,IllegalPadding,};inline constexpr QByteArray() noexcept {} //默认的构造函数//Constructs a byte array containing the first size bytes of array data.//If data is 0, a null byte array is constructed. 指向以'\0'结尾的字符串//If size is negative, data is assumed to point to a '\0'-terminated string and//its length is determined dynamically.//QByteArray makes a deep copy of the string data. 深复制QByteArray(const char * data, qsizetype size = -1);//Constructs a byte array of size size with every byte set to c.QByteArray(qsizetype size, char c);QByteArray(qsizetype size, Qt::Initialization); //没有关于 Qt::Initialization的注释explicit inline QByteArray(const DataPointer & dd) : d(dd) { } //有参构造inline QByteArray(const QByteArray & a) noexcept : d(a.d) {} //copy 构造函数inline QByteArray(QByteArray && other) noexcept // 移动构造函数{ qSwap(d, other.d); }QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QByteArray)inline ~QByteArray(){}
/* 以宏定义的形式实现了 移动赋值运算符函数
#define QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(Class) \Class &operator=(Class &&other) noexcept { \swap(other); \return *this; \}
*/QByteArray & operator=(const QByteArray &) noexcept; //copy赋值运算符函数QByteArray & operator=(const char * str);//说明本 QByteArray 类直接接受 c 语言风格字符串的赋值//QArrayDataPointer<char> d; 这是本类唯一的数据成员inline void swap(QByteArray & other) noexcept { d.swap(other.d); }//Returns the number of bytes in this byte array.//The last byte in the byte array is at position size() - 1.//In addition, QByteArray ensures that the byte at position size() is always '\0',//so that you can use the return value of data() and constData() as//arguments to functions that expect '\0'-terminated strings.//If the QByteArray object was created from a raw data that didn't include the//trailing '\0'-termination byte,//then QByteArray doesn't add it automatically unless a deep copy is created.inline qsizetype size () const { return d->size; }inline qsizetype count () const { return size(); }inline qsizetype length() const { return size(); }//综上，可见这三个函数是等价的，只是换个名字而已。返回本容器里实际包含的字节数void resize(qsizetype size); //Sets the size of the byte array to size bytes.//If size is greater than the current size,//the byte array is extended to make it size bytes with the extra//bytes added to the end. The new bytes are uninitialized.//If size is less than the current size,//bytes beyond position size are excluded from the byte array.//Note: While resize() will grow the capacity if needed,//it never shrinks capacity. To shed excess capacity, use squeeze().inline void squeeze() //从不需要调用本函数{if (!d.isMutable()) return;if (d->needsDetach() || size() < capacity())reallocData(size(), QArrayData::KeepSize);if (d->constAllocatedCapacity())d->clearFlag(Data::CapacityReserved);} //tuning调子；音调 fine细粒的;细微的；细小的;敏锐的//Releases any memory not required to store the array's data.//The sole purpose of this function is to provide a means of//fine tuning微调 QByteArray's memory usage.//In general, you will rarely ever need to call this function.inline void reserve(qsizetype size) //从不需要调用本函数{if (d->needsDetach() || asize > capacity() - d->freeSpaceAtBegin())reallocData(qMax(size(), asize), QArrayData::KeepSize);if (d->constAllocatedCapacity())d->setFlag(Data::CapacityReserved);}//Attempts to allocate memory for at least size bytes.//If you know in advance how large the byte array will be,//you can call this function,//and if you call resize() often you are likely to get better performance.//The sole purpose of this function is to provide a means of//fine tuning QByteArray's memory usage.//In general, you will rarely ever need to call this function.bool isNull() const; //以下成员函数的排列顺序是先读取属性后设置写入inline bool isEmpty() const { return size() == 0; } //多用这个inline qsizetype capacity() const //从不需要调用本函数{ return qsizetype(d->constAllocatedCapacity()); }//Returns the maximum number of bytes that can be stored in the//byte array without forcing a reallocation.//The sole purpose of this function is to provide a means of//fine tuning QByteArray's memory usage.//In general, you will rarely ever need to call this function.//If you want to know how many bytes are in the byte array, call size().inline DataPointer & data_ptr() { return d; } //返回本类中封装的数据成员给外界用//QArrayDataPointer<char> d;inline char * data() //返回堆区中的字节数组的起点{detach();Q_ASSERT(d.data());return d.data();}
/*
template <class T>
struct QArrayDataPointer
{Data * d ; //Data = QTypedArrayData<T> 包含了申请释放内存的成员方法T * ptr; //真正的堆区中的数据起点qsizetype size;T * data() { return ptr; }
};
*/inline const char * data() const{
#if QT5_NULL_STRINGS == 1return d.data() ? d.data() : &_empty;
#elsereturn d.data();
#endif}#ifndef QT_NO_CAST_FROM_BYTEARRAY //类型转换运算符函数。经本函数可以默认转换为 const char *inline operator const char *() const { return data(); }inline operator const void *() const { return data(); }
#endifinline const char * constData() const { return data(); }QByteArray & fill(char c, qsizetype size = -1);//Sets every byte in the byte array to ch.//If size is different from -1 (the default),//the byte array is resized to size size beforehand.操作前inline void detach() //这个函数没有注释，是为了分离共享，准备写入数据{if (d->needsDetach())reallocData(size(), QArrayData::KeepSize);}inline bool isDetached() const { return !d->isShared(); }inline bool isSharedWith(const QByteArray & other) const //共享即是严格等价{ return data() == other.data() && size() == other.size(); }//Returns true if this byte array contains only ASCII uppercase letters,//otherwise returns false.bool isUpper() const;bool isLower() const;//Returns true if this byte array contains only lowercase ASCII letters,//otherwise returns false.void clear();//Clears the contents of the byte array and makes it null.inline char at(qsizetype i) const{Q_ASSERT(size_t(i) < size_t(size()));return d.data()[i];}inline char operator[](qsizetype i) const{Q_ASSERT(size_t(i) < size_t(size()));return d.data()[i];}[[nodiscard]] inline char & operator[](qsizetype i){Q_ASSERT(i >= 0 && i < size());return data()[i];}[[nodiscard]] char front() const { return at(0); } //首字符[[nodiscard]] inline char & front() { return operator[](0); } //尾字符[[nodiscard]] char back() const { return at(size() - 1); }[[nodiscard]] inline char & back() { return operator[](size() - 1); }[[nodiscard]] QByteArray first(qsizetype n) const //取开头的 n 个字符{ Q_ASSERT(n >= 0); Q_ASSERT(n <= size());return QByteArray(data(), n);}[[nodiscard]] QByteArray last(qsizetype n) const //取末尾的 n 个字符{ Q_ASSERT(n >= 0); Q_ASSERT(n <= size());return QByteArray(data() + size() - n, n);}[[nodiscard]] QByteArray sliced(qsizetype pos) const //取下标 pos 开始的所有剩余字符{ Q_ASSERT(pos >= 0); Q_ASSERT(pos <= size());return QByteArray(data() + pos, size() - pos);}[[nodiscard]] QByteArray sliced(qsizetype pos, qsizetype n) const{ Q_ASSERT(pos >= 0); Q_ASSERT(n >= 0); //取下标 pos 开始的 n 个字符Q_ASSERT(size_t(pos) + size_t(n) <= size_t(size()));return QByteArray(data() + pos, n);}[[nodiscard]] QByteArray chopped(qsizetype len) const //扔掉末尾的 n 个字符{ Q_ASSERT(len >= 0); Q_ASSERT(len <= size());return first(size() - len);}void chop (qsizetype n ); //返回值不一样，修改的是自己，扔掉末尾的 n 个字符void truncate(qsizetype pos); //修改本字符串，扔掉下标 pos 开始的所有字符//If you know that len cannot be out of bounds,//use first() instead in new code, because it is faster.[[nodiscard]] QByteArray left (qsizetype len) const; //= first()，first 更好[[nodiscard]] QByteArray right(qsizetype len) const; //= last ()，last 更好[[nodiscard]] QByteArray mid(qsizetype index, qsizetype len = -1) const;//= sliced() sliced 更好bool startsWith(char c) const { return size() > 0 && front() == c; }bool startsWith(QByteArrayView bv) const{ return QtPrivate::startsWith(qToByteArrayViewIgnoringNull(*this), bv); }bool endsWith (char c) const { return size() > 0 && back () == c; }bool endsWith(QByteArrayView bv) const{ return QtPrivate::endsWith(qToByteArrayViewIgnoringNull(*this), bv); }//Returns the index position of the start of the first occurrence of the//byte c in this byte array, searching forward from index position from.//Returns -1 if no match is found. 从下标 from开始正向查找字符 c所在的下标,找不到返 -1qsizetype indexOf(char c, qsizetype from = 0) const;qsizetype indexOf(QByteArrayView bv, qsizetype from = 0) const{ return QtPrivate::findByteArray(qToByteArrayViewIgnoringNull(*this), from, bv); }//Returns the index position of the start of the last occurrence of//byte c in this byte array, searching backward from index position from.//If from is -1 (the default), 从下标 from开始逆向查找字符 c所在的下标,找不到返 -1//the search starts at the last byte (at index size() - 1).//Returns -1 if no match is found.qsizetype lastIndexOf(char c, qsizetype from = -1) const;qsizetype lastIndexOf(QByteArrayView bv) const{ return lastIndexOf(bv, size()); }qsizetype lastIndexOf(QByteArrayView bv, qsizetype from) const{ return QtPrivate::lastIndexOf(qToByteArrayViewIgnoringNull(*this), from, bv); }inline bool contains(char c ) const { return indexOf(c ) != -1; }inline bool contains(QByteArrayView bv) const { return indexOf(bv) != -1; }qsizetype count(char c) const; //返回字符串里字符 c 出现的次数//Returns the number of occurrences of byte c in the byte array.qsizetype count(QByteArrayView bv) const{ return QtPrivate::count(qToByteArrayViewIgnoringNull(*this), bv); }inline int compare(QByteArrayView a, //看不懂，也不了解 QByteArrayView，略Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept{return cs == Qt::CaseSensitive ? QtPrivate::compareMemory(*this, a) :qstrnicmp(data(), size(), a.data(), a.size());}typedef char * iterator; //本容器里的迭代器很简单，直接就是未封装的裸指针typedef iterator Iterator;typedef const char * const_iterator;typedef const_iterator ConstIterator;typedef std::reverse_iterator<iterator> reverse_iterator;typedef std::reverse_iterator<const_iterator> const_reverse_iterator;inline iterator begin() { return data(); } //返回指向字节的裸指针inline const_iterator begin() const { return data(); }inline const_iterator cbegin() const { return data(); }inline const_iterator constBegin() const { return data(); }inline iterator end() { return data() + size(); }inline const_iterator end() const { return data() + size(); }inline const_iterator cend() const { return data() + size(); }inline const_iterator constEnd() const { return data() + size(); }reverse_iterator rbegin(){ return reverse_iterator(end()); }const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }const_reverse_iterator crbegin() const{ return const_reverse_iterator(end()); }reverse_iterator rend(){ return reverse_iterator(begin()); }const_reverse_iterator rend() const{ return const_reverse_iterator(begin()); }const_reverse_iterator crend() const{ return const_reverse_iterator(begin()); }//将字节数组拆分为子数组，只要 sep出现，并返回这些数组的列表。//如果字节数组中没有任何地方与 sep 匹配,则 split()返回一个包含该字节数组的单元素列表。//拆分后的子字符串里都不再包含 sep 字符。"12abcade" -> "12" "bc" "de"QList<QByteArray> split(char sep) const;[[nodiscard]] QByteArray repeated(qsizetype times) const;//Returns a copy of this byte array repeated the specified number of times.//If times is less than 1, an empty byte array is returned.//经测试，这些成员函数都存在 ， #if 成立
//说明 QByteArray 类型的数据可以和 QString 类型的数据直接比较
#if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)QT_ASCII_CAST_WARN inline bool operator==(const QString &s2) const;QT_ASCII_CAST_WARN inline bool operator!=(const QString &s2) const;QT_ASCII_CAST_WARN inline bool operator< (const QString &s2) const;QT_ASCII_CAST_WARN inline bool operator> (const QString &s2) const;QT_ASCII_CAST_WARN inline bool operator<=(const QString &s2) const;QT_ASCII_CAST_WARN inline bool operator>=(const QString &s2) const;
#endiffriend inline //全局的运算符类友元函数bool operator==(const QByteArray &a1, const QByteArray & a2) noexcept{ return QByteArrayView(a1) == QByteArrayView(a2); }friend inline //左值引用形式的比较bool operator==(const QByteArray & a1, const char * a2) noexcept{ return a2 ? QtPrivate::compareMemory(a1, a2) == 0 : a1.isEmpty(); }friend inline //左值引用形式的比较bool operator==(const char * a1, const QByteArray & a2) noexcept{ return a1 ? QtPrivate::compareMemory(a1, a2) == 0 : a2.isEmpty(); }friend inline //左值引用形式的比较bool operator!=(const QByteArray & a1, const QByteArray & a2) noexcept{ return !(a1==a2); }friend inline //左值引用形式的比较bool operator!=(const QByteArray & a1, const char *a2) noexcept{ return a2 ? QtPrivate::compareMemory(a1, a2) != 0 : !a1.isEmpty(); }friend inlinebool operator!=(const char * a1, const QByteArray & a2) noexcept{ return a1 ? QtPrivate::compareMemory(a1, a2) != 0 : !a2.isEmpty(); }friend inlinebool operator<(const QByteArray &a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(QByteArrayView(a1), QByteArrayView(a2)) < 0; }friend inlinebool operator<(const QByteArray &a1, const char * a2) noexcept{ return QtPrivate::compareMemory(a1, a2) < 0; }friend inlinebool operator<(const char *a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(a1, a2) < 0; }friend inlinebool operator<=(const QByteArray &a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(QByteArrayView(a1), QByteArrayView(a2)) <= 0; }friend inlinebool operator<=(const QByteArray &a1, const char *a2) noexcept{ return QtPrivate::compareMemory(a1, a2) <= 0; }friend inlinebool operator<=(const char *a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(a1, a2) <= 0; }friend inlinebool operator>(const QByteArray &a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(QByteArrayView(a1), QByteArrayView(a2)) > 0; }friend inlinebool operator>(const QByteArray &a1, const char *a2) noexcept{ return QtPrivate::compareMemory(a1, a2) > 0; }friend inlinebool operator>(const char *a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(a1, a2) > 0; }friend inlinebool operator>=(const QByteArray &a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(QByteArrayView(a1), QByteArrayView(a2)) >= 0; }friend inlinebool operator>=(const QByteArray &a1, const char *a2) noexcept{ return QtPrivate::compareMemory(a1, a2) >= 0; }friend inlinebool operator>=(const char *a1, const QByteArray &a2) noexcept{ return QtPrivate::compareMemory(a1, a2) >= 0; }// Check isEmpty() instead of isNull() for backwards compatibility.friend inline //以下这些是处理与 std::nullptr_t 的比较bool operator==(const QByteArray &a1, std::nullptr_t) noexcept{ return a1.isEmpty(); }friend inline //与 std::nullptr_t 的比较更关注于相等或不等的比较bool operator!=(const QByteArray &a1, std::nullptr_t) noexcept{ return !a1.isEmpty(); }friend inlinebool operator< (const QByteArray & , std::nullptr_t) noexcept{ return false; }friend inlinebool operator> (const QByteArray &a1, std::nullptr_t) noexcept{ return !a1.isEmpty(); }friend inlinebool operator<=(const QByteArray &a1, std::nullptr_t) noexcept{ return a1.isEmpty(); }friend inlinebool operator>=(const QByteArray & , std::nullptr_t) noexcept{ return true; }friend inlinebool operator==(std::nullptr_t, const QByteArray &a2) noexcept{ return a2 == nullptr; }friend inlinebool operator!=(std::nullptr_t, const QByteArray &a2) noexcept{ return a2 != nullptr; }friend inlinebool operator< (std::nullptr_t, const QByteArray &a2) noexcept{ return a2 > nullptr; }friend inlinebool operator> (std::nullptr_t, const QByteArray &a2) noexcept{ return a2 < nullptr; }friend inlinebool operator<=(std::nullptr_t, const QByteArray &a2) noexcept{ return a2 >= nullptr; }friend inlinebool operator>=(std::nullptr_t, const QByteArray &a2) noexcept{ return a2 <= nullptr; }#if !defined(Q_CLANG_QDOC) //这些函数都是存在的//Returns a copy of the byte array in which each//ASCII uppercase letter converted to lowercase.[[nodiscard]] QByteArray toLower() const & //小写字符不动，把大写变成小写{ return toLower_helper(*this); }[[nodiscard]] QByteArray toLower() &&{ return toLower_helper(*this); }//Returns a copy of the byte array in which each//ASCII lowercase letter converted to uppercase.[[nodiscard]] QByteArray toUpper() const & //全部返回大写字符{ return toUpper_helper(*this); }[[nodiscard]] QByteArray toUpper() &&{ return toUpper_helper(*this); }//const &表示这是一个常量引用限定符，说明这个函数是左值引用的常量成员函数。//这意味着该函数只能被左值对象调用，并且不会修改对象的状态。//同时，const保证函数内部不会修改成员变量。[[nodiscard]] QByteArray trimmed() const &{ return trimmed_helper(*this); }//Returns a copy of this byte array with spacing characters removed from//the start and end.//The spacing characters are those for which the standard C++ isspace()//function returns true in the C locale;//these are the ASCII characters tabulation '\t', line feed '\n',//carriage return '\r', vertical tabulation '\v',//form feed '\f', and space ' '.[[nodiscard]] QByteArray trimmed() &&{ return trimmed_helper(*this); }//Returns a copy of this byte array that has spacing characters removed from//the start and end, and in which each sequence of internal spacing characters//is replaced with a single space.[[nodiscard]] QByteArray simplified() const &{ return simplified_helper(*this); }[[nodiscard]] QByteArray simplified() &&{ return simplified_helper(*this); }
#else[[nodiscard]] QByteArray toLower() const;[[nodiscard]] QByteArray toUpper() const;[[nodiscard]] QByteArray trimmed() const;[[nodiscard]] QByteArray simplified() const;
#endif//返回一个大小为 width 的字节数组，其中包含这个字节数组，并用 fill 字符填充。//如果 truncate是 false，且 byte 数组的 size()大于 width，//则返回的 byte 数组是此 byte 数组的副本。//如果 truncate为true，且byte 数组的 size()大于 width，//则删除位置 width 之后的 byte 数组副本中的任何字节，并返回副本。[[nodiscard]] QByteArray leftJustified (qsizetype width,char fill = ' ', bool truncate = false) const;//返回一个指定长度的新字节数组，原内容左对齐，右侧填充指定的字符，默认是空格。//函数可能有参数指定填充字符和是否截断原内容。//当原数组长度小于width时，右侧填充fill字符；//如果原长度超过width，是否截取取决于truncate参数是否为true。//Returns a byte array of size width that contains the fill byte followed by//this byte array.//If truncate is false and the size of the byte array is more than width,//then the returned byte array is a copy of this byte array.//If truncate is true and the size of the byte array is more than width,//then the resulting byte array is truncated at position width.[[nodiscard]] QByteArray rightJustified(qsizetype width,char fill = ' ', bool truncate = false) const;//通常用于将字符串右对齐，可能是在填充字符的情况下。//比如，将字符串调整到指定长度，右侧对齐，左侧填充空格或其他字符。//Returns the byte array converted to a short using base base,//which is ten by default. Bases 0 and 2 through 36 are supported,//using letters for digits beyond 9; A is ten, B is eleven and so on.//If base is 0, the base is determined automatically using the following rules://If the byte array begins with "0x", it is assumed to be hexadecimal;//otherwise, if it begins with "0", it is assumed to be octal;//otherwise it is assumed to be decimal.//Returns 0 if the conversion fails.//If ok is not nullptr, failure is reported by setting *ok to false,//and success by setting *ok to true.//Note: The conversion of the number is performed in the default C locale,//regardless of the user's locale.//Use QLocale to perform locale-aware conversions between numbers and strings.//经测试， 形参 base 指出字符串里的文本的数据进制。这些函数的输出结果都是 10进制short toShort (bool *ok = nullptr, int base = 10) const;ushort toUShort (bool *ok = nullptr, int base = 10) const;int toInt (bool *ok = nullptr, int base = 10) const;uint toUInt (bool *ok = nullptr, int base = 10) const;long toLong (bool *ok = nullptr, int base = 10) const;ulong toULong (bool *ok = nullptr, int base = 10) const;qlonglong toLongLong (bool *ok = nullptr, int base = 10) const;qulonglong toULongLong(bool *ok = nullptr, int base = 10) const;//Warning: The QByteArray content may only contain valid numerical characters//which includes the plus/minus sign,//the character e used in scientific notation, and the decimal point.//Including the unit or additional characters leads to a conversion error.//This function ignores leading and trailing whitespace.float toFloat (bool *ok = nullptr) const;double toDouble (bool *ok = nullptr) const;QByteArray toHex (char separator = '\0' ) const;//Returns a hex encoded copy of the byte array.//The hex encoding uses the numbers 0-9 and the letters a-f.//If separator is not '\0',//the separator character is inserted between the hex bytes.//本函把字符数组中的字符的 ascii码转换为十六进制输出，并以形参字符 separator间隔每个字符QByteArray toBase64(Base64Options options = Base64Encoding) const;QByteArray toPercentEncoding(const QByteArray &exclude = QByteArray(),const QByteArray &include = QByteArray(),char percent = '%') const;//Returns a URI/URL-style percent-encoded copy of this byte array.//The percent parameter allows you to override the default '%' character for//another. By default, this function will encode all bytes that are not//one of the following://ALPHA ("a" to "z" and "A" to "Z") / DIGIT (0 to 9) / "-" / "." / "_" / "~"//To prevent bytes from being encoded pass them to exclude.//To force bytes to be encoded pass them to include.//The percent character is always encoded. 不懂，先记录下[[nodiscard]] static QByteArray fromRawData(const char *data, qsizetype size){return QByteArray(DataPointer(nullptr, const_cast<char *>(data), size));}[[nodiscard]] static QByteArray fromPercentEncoding(const QByteArray &pctEncoded, char percent = '%');class FromBase64Result;[[nodiscard]] static FromBase64Result fromBase64Encoding(QByteArray &&base64, Base64Options options = Base64Encoding);[[nodiscard]] static FromBase64Result fromBase64Encoding(const QByteArray &base64, Base64Options options = Base64Encoding);[[nodiscard]] static QByteArray fromBase64(const QByteArray &base64, Base64Options options = Base64Encoding);[[nodiscard]] static QByteArray fromHex(const QByteArray &hexEncoded);//Returns a decoded copy of the hex encoded array hexEncoded.//Input is not checked for validity;//invalid characters in the input are skipped,//enabling the decoding process to continue with subsequent characters.//For example:// QByteArray text = QByteArray::fromHex("517420697320677265617421");// text.data(); // returns "Qt is great!"//本静态函数把形参中的字符作为 16进制的 ascii码转换为对应的字符，存储在字节数组中返回//number()系列把形参 1中的十进制数按形参 2的进制转换后，作为字符串输出[[nodiscard]] static QByteArray number(int , int base = 10);[[nodiscard]] static QByteArray number(uint , int base = 10);[[nodiscard]] static QByteArray number(long , int base = 10);[[nodiscard]] static QByteArray number(ulong , int base = 10);[[nodiscard]] static QByteArray number(qlonglong , int base = 10);[[nodiscard]] static QByteArray number(qulonglong, int base = 10);[[nodiscard]] static QByteArray number(double , char format = 'g',int precision = 6);//eturns a byte-array representing the floating-point number n as text.//Returns a byte array containing a string representing n,//with a given format and precision,//with the same meanings as for QString::number(double, char, int).//For example://QByteArray ba = QByteArray::number(12.3456, 'E', 3);// ba == 1.235E+01static inline QByteArray fromStdString(const std::string &s){ return QByteArray(s.data(), qsizetype(s.size())); }inline std::string toStdString() const{ return std::string(constData(), length()); }//这些函数没有静态函数好用，自然inline QByteArray &setNumsetNum(ushort n, int base = 10){ return setNum(qulonglong(n), base); }inline QByteArray &setNum(short n, int base = 10){ return setNum(qlonglong(n) , base); }inline QByteArray &setNum( int n, int base = 10){ return setNum(qlonglong(n), base); }inline QByteArray &setNum(uint n, int base = 10){ return setNum(qulonglong(n), base); }inline QByteArray &setNum( long n, int base = 10){ return setNum(qlonglong(n), base); }inline QByteArray &setNum(ulong n, int base = 10){ return setNum(qulonglong(n), base); }QByteArray &setNum(qlonglong , int base = 10);QByteArray &setNum(qulonglong, int base = 10);inline QByteArray &setNum(float n, char format, int precision = 6){ return setNum(double(n), format, precision); }QByteArray &setNum(double, char format = 'g', int precision = 6);QByteArray &setRawData(const char *a, qsizetype n);#if defined(Q_OS_DARWIN) || defined(Q_QDOC) //略static QByteArray fromCFData(CFDataRef data);static QByteArray fromRawCFData(CFDataRef data);CFDataRef toCFData() const Q_DECL_CF_RETURNS_RETAINED;CFDataRef toRawCFData() const Q_DECL_CF_RETURNS_RETAINED;static QByteArray fromNSData(const NSData *data);static QByteArray fromRawNSData(const NSData *data);NSData *toNSData() const Q_DECL_NS_RETURNS_AUTORELEASED;NSData *toRawNSData() const Q_DECL_NS_RETURNS_AUTORELEASED;
#endifQByteArray & prepend(char c) //Prepends the byte c to this byte array.{ return insert(0, QByteArrayView(&c, 1)); }inline //Prepends count copies of byte c to this byte array.QByteArray & prepend(qsizetype count, char c){ return insert(0, n, ch); }//Prepends the '\0'-terminated string s to this byte array.QByteArray & prepend(const char * s){ return insert(0, QByteArrayView(s, qsizetype(qstrlen(s)))); }QByteArray & prepend(const char * s, qsizetype len){ return insert(0, QByteArrayView(s, len)); }//Prepends len bytes starting at str to this byte array.//The bytes prepended may include '\0' bytes.QByteArray & prepend(const QByteArray &a);QByteArray & prepend(QByteArrayView a){ return insert(0, a); }QByteArray & append(char c);inlineQByteArray & append(qsizetype count, char c){ return insert(size(), n, ch); }QByteArray & append(const char *s){ return append(QByteArrayView(s, qsizetype(qstrlen(s)))); }QByteArray & append(const char *s, qsizetype len){ return append(QByteArrayView(s, len)); }QByteArray & append(const QByteArray &a);QByteArray & append(QByteArrayView a){ return insert(size(), a); }QByteArray &operator+=(char c){ return append(c); }QByteArray &operator+=(const char *s){ return append(s); }QByteArray &operator+=(const QByteArray &a){ return append(a); }QByteArray &operator+=(QByteArrayView a){ return append(a); }QByteArray & insert(qsizetype i, QByteArrayView data);QByteArray & insert(qsizetype i, char c){ return insert(i, QByteArrayView(&c, 1)); }QByteArray & insert(qsizetype i, qsizetype count, char c);inlineQByteArray & insert(qsizetype i, const char * s){ return insert(i, QByteArrayView(s)); }//Inserts len bytes, starting at s, at position i in the byte array.//This array grows to accommodate the insertion.//If i is beyond the end of the array,//the array is first extended with space characters to reach this i.QByteArray & insert(qsizetype i, const char * s, qsizetype len){ return insert(i, QByteArrayView(s, len)); }inlineQByteArray & insert(qsizetype i, const QByteArray & data){ return insert(i, QByteArrayView(data)); }QByteArray & replace(qsizetype index, qsizetype len, QByteArrayView s);QByteArray & replace(char before, QByteArrayView after){ return replace(QByteArrayView(&before, 1), after); }QByteArray & replace(QByteArrayView before, QByteArrayView after);//Replaces every occurrence of the byte before with the byte after.QByteArray & replace(char before, char after);//Replaces len bytes from index position pos with alen bytes starting at//position after. The bytes inserted may include '\0' bytes.QByteArray & replace(qsizetype index, qsizetype len,const char * s , qsizetype alen){ return replace(index, len, QByteArrayView(s, alen)); }QByteArray & replace(const char * before, qsizetype bsize,const char * after , qsizetype asize){ return replace(QByteArrayView(before, bsize), QByteArrayView(after, asize)); }//Replaces every occurrence of the bsize bytes starting at before with the//asize bytes starting at after.//Since the sizes of the strings are given by bsize and asize,//they may contain '\0' bytes and do not need to be '\0'-terminated.//Removes len bytes from the array, starting at index position pos,//and returns a reference to the array.//If pos is out of range, nothing happens.//If pos is valid, but pos + len is larger than the size of the array,//the array is truncated at position pos.//Element removal will preserve the array's capacity and not reduce the//amount of allocated memory.//To shed extra capacity and free as much memory as possible,//call squeeze() after the last change to the array's size.QByteArray & remove(qsizetype index, qsizetype len);template <typename Predicate> //带断言的删除QByteArray & removeIf(Predicate pred){QtPrivate::sequential_erase_if(*this, pred);return *this;}// stl compatibility 与 STL 的兼容typedef qsizetype size_type;typedef qptrdiff difference_type;typedef const char & const_reference;typedef char & reference;typedef char * pointer;typedef const char * const_pointer;typedef char value_type;void push_back(char c) //为了兼容，实际上本 QT写的 append prepend 就很好{ append(c); }void push_back(const char * s){ append(s); }void push_back(const QByteArray & a){ append(a); }void push_back(QByteArrayView a){ append(a); }void push_front(char c){ prepend(c); }void push_front(const char * c){ prepend(c); }void push_front(const QByteArray & a){ prepend(a); }void push_front(QByteArrayView a){ prepend(a); }void shrink_to_fit() { squeeze(); }iterator erase(const_iterator first, const_iterator last);//这个函数的使用，要使用迭代器作为参数private:void reallocData(qsizetype alloc, QArrayData::AllocationOption option);void reallocGrowData(qsizetype n);void expand(qsizetype i);QByteArray nulTerminated() const;static QByteArray toLower_helper(const QByteArray &a);static QByteArray toLower_helper(QByteArray &a);static QByteArray toUpper_helper(const QByteArray &a);static QByteArray toUpper_helper(QByteArray &a);static QByteArray trimmed_helper(const QByteArray &a);static QByteArray trimmed_helper(QByteArray &a);static QByteArray simplified_helper(const QByteArray &a);static QByteArray simplified_helper(QByteArray &a);friend class QString; //友元类friend Q_CORE_EXPORTQByteArray qUncompress(const uchar *data, qsizetype nbytes);}; //完结 class QByteArrayQ_DECLARE_OPERATORS_FOR_FLAGS(QByteArray::Base64Options)#if !defined(QT_USE_QSTRINGBUILDER) //定义了全局函数 + 运算符。本 if 有效，有这些函数
inline const QByteArray operator+(const QByteArray & a1, const QByteArray & a2)
{ return QByteArray(a1) += a2; }inline const QByteArray operator+(const QByteArray & a1, const char * a2)
{ return QByteArray(a1) += a2; }inline const QByteArray operator+(const QByteArray & a1, char a2)
{ return QByteArray(a1) += a2; }inline const QByteArray operator+(const char * a1, const QByteArray & a2)
{ return QByteArray(a1) += a2; }inline const QByteArray operator+(char a1, const QByteArray & a2)
{ return QByteArray(&a1, 1) += a2; }#endif // QT_USE_QSTRINGBUILDER//定义 <<、>> 运算符对本 QByteArray 类的支持
#if !defined(QT_NO_DATASTREAM) || defined(QT_BOOTSTRAPPED)
Q_CORE_EXPORT QDataStream & operator<<(QDataStream &, const QByteArray &);
Q_CORE_EXPORT QDataStream & operator>>(QDataStream &, QByteArray &);
#endif#ifndef QT_NO_COMPRESS
Q_CORE_EXPORT QByteArray qCompress(const uchar* data,qsizetype nbytes, int compressionLevel = -1);inline QByteArray qCompress(const QByteArray& data, int compressionLevel = -1)
{ return qCompress(reinterpret_cast<const uchar *>(data.constData()),data.size(), compressionLevel);
}Q_CORE_EXPORT QByteArray qUncompress(const uchar* data, qsizetype nbytes);inline QByteArray qUncompress(const QByteArray& data)
{ return qUncompress(reinterpret_cast<const uchar*>(data.constData()),data.size());
}
#endifQ_DECLARE_SHARED(QByteArray)class QByteArray::FromBase64Result
{
public:QByteArray decoded;QByteArray::Base64DecodingStatus decodingStatus;void swap(QByteArray::FromBase64Result &other) noexcept{decoded.swap(other.decoded);std::swap(decodingStatus, other.decodingStatus);}explicit operator bool() const noexcept { return decodingStatus == QByteArray::Base64DecodingStatus::Ok; }#if defined(Q_COMPILER_REF_QUALIFIERS) && !defined(Q_QDOC)QByteArray &operator*() & noexcept { return decoded; }const QByteArray &operator*() const & noexcept { return decoded; }QByteArray &&operator*() && noexcept { return std::move(decoded); }
#elseQByteArray &operator*() noexcept { return decoded; }const QByteArray &operator*() const noexcept { return decoded; }
#endiffriend inline bool operator==(const QByteArray::FromBase64Result &lhs, const QByteArray::FromBase64Result &rhs) noexcept{if (lhs.decodingStatus != rhs.decodingStatus)return false;if (lhs.decodingStatus == QByteArray::Base64DecodingStatus::Ok && lhs.decoded != rhs.decoded)return false;return true;}friend inline bool operator!=(const QByteArray::FromBase64Result &lhs, const QByteArray::FromBase64Result &rhs) noexcept{return !(lhs == rhs);}
};Q_DECLARE_SHARED(QByteArray::FromBase64Result)Q_CORE_EXPORT Q_DECL_PURE_FUNCTION size_t qHash(const QByteArray::FromBase64Result &key, size_t seed = 0) noexcept;template <typename T>
qsizetype erase(QByteArray &ba, const T &t)
{return QtPrivate::sequential_erase(ba, t);
}template <typename Predicate>
qsizetype erase_if(QByteArray &ba, Predicate pred)
{return QtPrivate::sequential_erase_if(ba, pred);
}//
// QByteArrayView members that require QByteArray:
//
QByteArray QByteArrayView::toByteArray() const
{return QByteArray(data(), size());
}inline namespace QtLiterals {
inline QByteArray operator"" _qba(const char *str, size_t size) noexcept
{return QByteArray(QByteArrayData(nullptr, const_cast<char *>(str), qsizetype(size)));
}
} // QtLiteralsQT_END_NAMESPACE#endif // QBYTEARRAY_H（7）
谢谢
