QUuid 类

QUuid 类存储 UUID (通用唯一标识符)。 更多...

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

QBluetoothUuid

注意: 此类的所有函数 可重入 .

公共类型

(从 6.6 起) union Id128Bytes
enum StringFormat { WithBraces, WithoutBraces, Id128 }
enum Variant { VarUnknown, NCS, DCE, Microsoft, Reserved }
enum 版本 { VerUnknown, Time, EmbeddedPOSIX, Name, Md5, …, Sha1 }

公共函数

QUuid ()
QUuid (uint l , ushort w1 , ushort w2 , uchar b1 , uchar b2 , uchar b3 , uchar b4 , uchar b5 , uchar b6 , uchar b7 , uchar b8 )
(从 6.6 起) QUuid (QUuid::Id128Bytes id128 , QSysInfo::Endian order = QSysInfo::BigEndian)
QUuid (QAnyStringView text )
QUuid (const GUID & guid )
bool isNull () const
QByteArray toByteArray (QUuid::StringFormat mode = WithBraces) const
(从 6.6 起) QUuid::Id128Bytes toBytes (QSysInfo::Endian order = QSysInfo::BigEndian) const
CFUUIDRef toCFUUID () const
NSUUID * toNSUUID () const
QByteArray toRfc4122 () const
QString toString (QUuid::StringFormat mode = WithBraces) const
(从 6.6 起) quint128 toUInt128 (QSysInfo::Endian order = QSysInfo::BigEndian) const
QUuid::Variant variant () const
QUuid::Version version () const
GUID operator GUID () const
bool operator!= (const QUuid & other ) const
bool operator!= (const GUID & guid ) const
bool operator< (const QUuid & other ) const
QUuid & operator= (const GUID & guid )
bool operator== (const QUuid & other ) const
bool operator== (const GUID & guid ) const
bool operator> (const QUuid & other ) const

静态公共成员

QUuid createUuid ()
QUuid createUuidV3 (const QUuid & ns , const QByteArray & baseData )
QUuid createUuidV3 (const QUuid & ns , const QString & baseData )
QUuid createUuidV5 (const QUuid & ns , const QByteArray & baseData )
QUuid createUuidV5 (const QUuid & ns , const QString & baseData )
(从 6.6 起) QUuid fromBytes (const void * bytes , QSysInfo::Endian order = QSysInfo::BigEndian)
QUuid fromCFUUID (CFUUIDRef uuid )
QUuid fromNSUUID (const NSUUID * uuid )
QUuid fromRfc4122 (QByteArrayView bytes )
QUuid fromString (QAnyStringView string )
(从 6.6 起) QUuid fromUInt128 (quint128 uuid , QSysInfo::Endian order = QSysInfo::BigEndian)
size_t qHash (const QUuid & uuid , size_t seed = 0)
QDataStream & operator<< (QDataStream & s , const QUuid & id )
QDebug operator<< (QDebug dbg , const QUuid & id )
bool operator<= (const QUuid & lhs , const QUuid & rhs )
bool operator>= (const QUuid & lhs , const QUuid & rhs )
QDataStream & operator>> (QDataStream & s , QUuid & id )

详细描述

使用 U niversally U nique ID entifiers (UUID) is a standard way to uniquely identify entities in a distributed computing environment. A UUID is a 16-byte (128-bit) number generated by some algorithm that is meant to guarantee that the UUID will be unique in the distributed computing environment where it is used. The acronym GUID is often used instead, G lobally U nique ID entifiers, but it refers to the same thing.

Actually, the GUID is one variant of UUID. Multiple variants are in use. Each UUID contains a bit field that specifies which type (variant) of UUID it is. Call variant () to discover which type of UUID an instance of QUuid contains. It extracts the three most significant bits of byte 8 of the 16 bytes. In QUuid, byte 8 is QUuid::data4[0] . If you create instances of QUuid using the constructor that accepts all the numeric values as parameters, use the following table to set the three most significant bits of parameter b1 , which becomes QUuid::data4[0] and contains the variant field in its three most significant bits. In the table, 'x' means don't care .

msb0 msb1 msb2 Variant
0 x x NCS (Network Computing System)
1 0 x DCE (Distributed Computing Environment)
1 1 0 Microsoft (GUID)
1 1 1 Reserved for future expansion

variant () 返回 QUuid::DCE , the UUID also contains a version field in the four most significant bits of QUuid::data3 , and you can call version () to discover which version your QUuid contains. If you create instances of QUuid using the constructor that accepts all the numeric values as parameters, use the following table to set the four most significant bits of parameter w2 , which becomes QUuid::data3 and contains the version field in its four most significant bits.

msb0 msb1 msb2 msb3 版本
0 0 0 1 时间
0 0 1 0 Embedded POSIX
0 0 1 1 Md5(Name)
0 1 0 0 Random
0 1 0 1 Sha1

The field layouts for the DCE versions listed in the table above are specified in the Network Working Group UUID Specification .

Most platforms provide a tool for generating new UUIDs, e.g. uuidgen and guidgen 。还可以使用 createUuid (). UUIDs generated by createUuid () are of the random type. Their QUuid::Version bits are set to QUuid::Random , and their QUuid::Variant bits are set to QUuid::DCE . The rest of the UUID is composed of random numbers. Theoretically, this means there is a small chance that a UUID generated by createUuid () will not be unique. But it is a very small chance .

UUIDs can be constructed from numeric values or from strings, or using the static createUuid () function. They can be converted to a string with toString (). UUIDs have a variant () 和 version (), and null UUIDs return true from isNull ().

成员类型文档编制

enum QUuid:: StringFormat

此枚举用于 toString (StringFormat) to control the formatting of the string representation. The possible values are:

常量 描述
QUuid::WithBraces 0 The default, toString () will return five hex fields, separated by dashes and surrounded by braces. Example: {00000000-0000-0000-0000-000000000000}.
QUuid::WithoutBraces 1 Only the five dash-separated fields, without the braces. Example: 00000000-0000-0000-0000-000000000000.
QUuid::Id128 3 Only the hex digits, without braces or dashes. Note that QUuid cannot parse this back again as input.

enum QUuid:: Variant

This enum defines the values used in the variant field of the UUID. The value in the variant field determines the layout of the 128-bit value.

常量 描述
QUuid::VarUnknown -1 Variant is unknown
QUuid::NCS 0 Reserved for NCS (Network Computing System) backward compatibility
QUuid::DCE 2 Distributed Computing Environment, the scheme used by QUuid
QUuid::Microsoft 6 Reserved for Microsoft backward compatibility (GUID)
QUuid::Reserved 7 Reserved for future definition

enum QUuid:: 版本

This enum defines the values used in the version field of the UUID. The version field is meaningful only if the value in the variant field is QUuid::DCE .

常量 描述
QUuid::VerUnknown -1 Version is unknown
QUuid::Time 1 Time-based, by using timestamp, clock sequence, and MAC network card address (if available) for the node sections
QUuid::EmbeddedPOSIX 2 DCE Security version, with embedded POSIX UUIDs
QUuid::Name Md5 Name-based, by using values from a name for all sections
QUuid::Md5 3 Alias for Name
QUuid::Random 4 Random-based, by using random numbers for all sections
QUuid::Sha1 5

成员函数文档编制

[constexpr noexcept] QUuid:: QUuid ()

Creates the null UUID. toString () will output the null UUID as "{00000000-0000-0000-0000-000000000000}".

[constexpr noexcept] QUuid:: QUuid ( uint l , ushort w1 , ushort w2 , uchar b1 , uchar b2 , uchar b3 , uchar b4 , uchar b5 , uchar b6 , uchar b7 , uchar b8 )

Creates a UUID with the value specified by the parameters, l , w1 , w2 , b1 , b2 , b3 , b4 , b5 , b6 , b7 , b8 .

范例:

// {67C8770B-44F1-410A-AB9A-F9B5446F13EE}
QUuid IID_MyInterface(0x67c8770b, 0x44f1, 0x410a, 0xab, 0x9a, 0xf9, 0xb5, 0x44, 0x6f, 0x13, 0xee);
					

[explicit noexcept, since 6.6] QUuid:: QUuid ( QUuid::Id128Bytes id128 , QSysInfo::Endian order = QSysInfo::BigEndian)

Creates a QUuid based on the integral id128 parameter. The input id128 parameter is considered to have byte order order .

该函数在 Qt 6.6 引入。

另请参阅 fromBytes (), toBytes (), toRfc4122 (),和 toUInt128 ().

[explicit noexcept] QUuid:: QUuid ( QAnyStringView text )

Creates a QUuid object from the string text , which must be formatted as five hex fields separated by '-', e.g., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where each 'x' is a hex digit. The curly braces shown here are optional, but it is normal to include them. If the conversion fails, a null UUID is created. See toString () for an explanation of how the five hex fields map to the public data members in QUuid.

注意: In Qt versions prior to 6.3, this constructor was an overload set consisting of QString , QByteArray and const char* instead of one constructor taking QAnyStringView .

另请参阅 toString () 和 QUuid ().

[constexpr noexcept] QUuid:: QUuid (const GUID & guid )

Casts a Windows guid to a Qt QUuid.

警告: This function is only for Windows platforms.

[static] QUuid QUuid:: createUuid ()

On any platform other than Windows, this function returns a new UUID with variant QUuid::DCE and version QUuid::Random . On Windows, a GUID is generated using the Windows API and will be of the type that the API decides to create.

另请参阅 variant () 和 version ().

[static] QUuid QUuid:: createUuidV3 (const QUuid & ns , const QByteArray & baseData )

This function returns a new UUID with variant QUuid::DCE and version QUuid::Md5 . ns is the namespace and baseData is the basic data as described by RFC 4122.

另请参阅 variant (), version (),和 createUuidV5 ().

[static] QUuid QUuid:: createUuidV3 (const QUuid & ns , const QString & baseData )

This function returns a new UUID with variant QUuid::DCE and version QUuid::Md5 . ns is the namespace and baseData is the basic data as described by RFC 4122.

另请参阅 variant (), version (),和 createUuidV5 ().

[static] QUuid QUuid:: createUuidV5 (const QUuid & ns , const QByteArray & baseData )

This function returns a new UUID with variant QUuid::DCE and version QUuid::Sha1 . ns is the namespace and baseData is the basic data as described by RFC 4122.

另请参阅 variant (), version (),和 createUuidV3 ().

[static] QUuid QUuid:: createUuidV5 (const QUuid & ns , const QString & baseData )

This function returns a new UUID with variant QUuid::DCE and version QUuid::Sha1 . ns is the namespace and baseData is the basic data as described by RFC 4122.

另请参阅 variant (), version (),和 createUuidV3 ().

[static, since 6.6] QUuid QUuid:: fromBytes (const void * bytes , QSysInfo::Endian order = QSysInfo::BigEndian)

Reads 128 bits (16 bytes) from bytes using byte order order and returns the QUuid corresponding to those bytes. This function does the same as fromRfc4122 () if the byte order order is QSysInfo::BigEndian .

该函数在 Qt 6.6 引入。

另请参阅 fromRfc4122 ().

[static] QUuid QUuid:: fromCFUUID ( CFUUIDRef uuid )

构造新的 QUuid 包含副本 uuid CFUUID.

注意: this function is only available on Apple platforms.

[static] QUuid QUuid:: fromNSUUID (const NSUUID * uuid )

构造新的 QUuid 包含副本 uuid NSUUID.

注意: this function is only available on Apple platforms.

[static noexcept] QUuid QUuid:: fromRfc4122 ( QByteArrayView bytes )

创建 QUuid object from the binary representation of the UUID, as specified by RFC 4122 section 4.1.2. See toRfc4122 () for a further explanation of the order of bytes required.

The byte array accepted is NOT a human readable format.

If the conversion fails, a null UUID is created.

注意: In Qt versions prior to 6.3, this function took QByteArray , not QByteArrayView .

另请参阅 toRfc4122 (), QUuid (),和 fromBytes ().

[static noexcept] QUuid QUuid:: fromString ( QAnyStringView string )

创建 QUuid object from the string string , which must be formatted as five hex fields separated by '-', e.g., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where each 'x' is a hex digit. The curly braces shown here are optional, but it is normal to include them. If the conversion fails, a null UUID is returned. See toString () for an explanation of how the five hex fields map to the public data members in QUuid .

注意: In Qt versions prior to 6.3, this function was an overload set consisting of QStringView and QLatin1StringView instead of one function taking QAnyStringView .

另请参阅 toString () 和 QUuid ().

[static constexpr noexcept, since 6.6] QUuid QUuid:: fromUInt128 ( quint128 uuid , QSysInfo::Endian order = QSysInfo::BigEndian)

创建 QUuid based on the integral uuid parameter. The input uuid parameter is considered to have byte order order .

注意: This function is only present on platforms that offer a 128-bit integer type.

该函数在 Qt 6.6 引入。

另请参阅 toUInt128 (), fromBytes (), toBytes (),和 toRfc4122 ().

[noexcept] bool QUuid:: isNull () const

返回 true if this is the null UUID {00000000-0000-0000-0000-000000000000}; otherwise returns false .

QByteArray QUuid:: toByteArray ( QUuid::StringFormat mode = WithBraces) const

Returns the string representation of this QUuid , with the formattiong controlled by the mode parameter. From left to right, the five hex fields are obtained from the four public data members in QUuid 如下:

Field #
1 data1
2 data2
3 data3
4 data4[0] .. data4[1]
5 data4[2] .. data4[7]

[noexcept, since 6.6] QUuid::Id128Bytes QUuid:: toBytes ( QSysInfo::Endian order = QSysInfo::BigEndian) const

Returns a 128-bit ID created from this QUuid on the byte order specified by order . The binary content of this function is the same as toRfc4122 () if the order is QSysInfo::BigEndian . See that function for more details.

该函数在 Qt 6.6 引入。

另请参阅 toRfc4122 (), fromBytes (),和 QUuid ().

CFUUIDRef QUuid:: toCFUUID () const

Creates a CFUUID from a QUuid .

The caller owns the CFUUID and is responsible for releasing it.

注意: this function is only available on Apple platforms.

NSUUID *QUuid:: toNSUUID () const

Creates a NSUUID from a QUuid .

The NSUUID is autoreleased.

注意: this function is only available on Apple platforms.

QByteArray QUuid:: toRfc4122 () const

Returns the binary representation of this QUuid . The byte array is in big endian format, and formatted according to RFC 4122, section 4.1.2 - "Layout and byte order".

The order is as follows:

Field #
1 data1
2 data2
3 data3
4 data4[0] .. data4[7]

The bytes in the byte array returned by this function contains the same binary content as toBytes ().

另请参阅 toBytes ().

QString QUuid:: toString ( QUuid::StringFormat mode = WithBraces) const

Returns the string representation of this QUuid , with the formattiong controlled by the mode parameter. From left to right, the five hex fields are obtained from the four public data members in QUuid 如下:

Field #
1 data1
2 data2
3 data3
4 data4[0] .. data4[1]
5 data4[2] .. data4[7]

[constexpr noexcept, since 6.6] quint128 QUuid:: toUInt128 ( QSysInfo::Endian order = QSysInfo::BigEndian) const

Returns a 128-bit integer created from this QUuid on the byte order specified by order . The binary content of this function is the same as toRfc4122 () if the order is QSysInfo::BigEndian . See that function for more details.

注意: This function is only present on platforms that offer a 128-bit integer type.

该函数在 Qt 6.6 引入。

另请参阅 toRfc4122 (), fromUInt128 (), toBytes (), fromBytes (),和 QUuid ().

[noexcept] QUuid::Variant QUuid:: variant () const

Returns the value in the variant field of the UUID. If the return value is QUuid::DCE ,调用 version () to see which layout it uses. The null UUID is considered to be of an unknown variant.

另请参阅 version ().

[noexcept] QUuid::Version QUuid:: version () const

返回 version field of the UUID, if the UUID's variant field is QUuid::DCE . Otherwise it returns QUuid::VerUnknown .

另请参阅 variant ().

[constexpr noexcept] GUID QUuid:: operator GUID () const

Returns a Windows GUID from a QUuid .

警告: This function is only for Windows platforms.

[constexpr noexcept] bool QUuid:: operator!= (const QUuid & other ) const

返回 true 若此 QUuid other QUuid are different; otherwise returns false .

[constexpr noexcept] bool QUuid:: operator!= (const GUID & guid ) const

返回 true if this UUID is not equal to the Windows GUID guid ;否则返回 false .

[noexcept] bool QUuid:: operator< (const QUuid & other ) const

返回 true 若此 QUuid has the same variant field 作为 other QUuid and is lexicographically before the other QUuid 。若 other QUuid has a different variant field, the return value is determined by comparing the two variants .

另请参阅 variant ().

[constexpr noexcept] QUuid &QUuid:: operator= (const GUID & guid )

Assigns a Windows guid to a Qt QUuid .

警告: This function is only for Windows platforms.

[constexpr noexcept] bool QUuid:: operator== (const QUuid & other ) const

返回 true 若此 QUuid other QUuid are identical; otherwise returns false .

[constexpr noexcept] bool QUuid:: operator== (const GUID & guid ) const

返回 true if this UUID is equal to the Windows GUID guid ;否则返回 false .

[noexcept] bool QUuid:: operator> (const QUuid & other ) const

返回 true 若此 QUuid has the same variant field 作为 other QUuid and is lexicographically after the other QUuid 。若 other QUuid has a different variant field, the return value is determined by comparing the two variants .

另请参阅 variant ().

相关非成员

[noexcept] size_t qHash (const QUuid & uuid , size_t seed = 0)

Returns a hash of the UUID uuid ,使用 seed 做计算种子。

QDataStream & operator<< ( QDataStream & s , const QUuid & id )

Writes the UUID id 到数据流 s .

QDebug operator<< ( QDebug dbg , const QUuid & id )

Writes the UUID id to the output stream for debugging information dbg .

[noexcept] bool operator<= (const QUuid & lhs , const QUuid & rhs )

返回 true if lhs has the same variant field as rhs and is lexicographically not after rhs 。若 rhs has a different variant field, the return value is determined by comparing the two variants .

另请参阅 variant ().

[noexcept] bool operator>= (const QUuid & lhs , const QUuid & rhs )

返回 true if lhs has the same variant field as rhs and is lexicographically not before rhs 。若 rhs has a different variant field, the return value is determined by comparing the two variants .

另请参阅 variant ().

QDataStream & operator>> ( QDataStream & s , QUuid & id )

Reads a UUID from the stream s into id .