QUuid ¶

概要 ¶

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

若 variant() 返回 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	Time
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 . You can also use createUuid() . UUIDs generated by createUuid() are of the random type. Their 版本 bits are set to Random , and their Variant bits are set to 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 very ` < http://en.wikipedia.org/wiki/Universally_Unique_Identifier#Random_UUID_probability_of_duplicates >`_ 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() .

class QUuid ¶

QUuid(arg__1)

QUuid(arg__1)

QUuid(arg__1)

QUuid(l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8)

param b8

uchar

param l

uint

param arg__1

QByteArray

param b1

uchar

param b2

uchar

param b3

uchar

param b4

uchar

param b5

uchar

param w1

ushort

param b6

uchar

param w2

ushort

param b7

uchar

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

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}
IID_MyInterface = QUuid(0x67c8770b, 0x44f1, 0x410a, 0xab, 0x9a, 0xf9, 0xb5, 0x44, 0x6f, 0x13, 0xee)
											

PySide2.QtCore.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	Variant is unknown
QUuid.NCS	Reserved for NCS (Network Computing System) backward compatibility
QUuid.DCE	Distributed Computing Environment, the scheme used by QUuid
QUuid.Microsoft	Reserved for Microsoft backward compatibility (GUID)
QUuid.Reserved	Reserved for future definition

PySide2.QtCore.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 DCE .

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

PySide2.QtCore.QUuid. StringFormat ¶

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

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

PySide2.QtCore.QUuid. __reduce__ ( ) ¶

返回类型

PyObject

PySide2.QtCore.QUuid. __repr__ ( ) ¶

返回类型

PyObject

static PySide2.QtCore.QUuid. createUuid ( ) ¶

返回类型

QUuid

On any platform other than Windows, this function returns a new UUID with variant DCE and version 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() version()

static PySide2.QtCore.QUuid. createUuidV3 ( ns , baseData ) ¶

参数

• ns – QUuid

• baseData – QByteArray

返回类型

QUuid

static PySide2.QtCore.QUuid. createUuidV3 ( ns , baseData ) ¶

参数

• ns – QUuid

• baseData – unicode

返回类型

QUuid

static PySide2.QtCore.QUuid. createUuidV5 ( ns , baseData ) ¶

参数

• ns – QUuid

• baseData – QByteArray

返回类型

QUuid

static PySide2.QtCore.QUuid. createUuidV5 ( ns , baseData ) ¶

参数

• ns – QUuid

• baseData – unicode

返回类型

QUuid

static PySide2.QtCore.QUuid. fromRfc4122 ( arg__1 ) ¶

参数

arg__1 – QByteArray

返回类型

QUuid

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.

另请参阅

toRfc4122() QUuid()

PySide2.QtCore.QUuid. isNull ( ) ¶

返回类型

bool

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

PySide2.QtCore.QUuid. __ne__ ( orig ) ¶

参数

orig – QUuid

返回类型

bool

PySide2.QtCore.QUuid. __lt__ ( other ) ¶

参数

other – QUuid

返回类型

bool

PySide2.QtCore.QUuid. __le__ ( rhs ) ¶

参数

rhs – QUuid

返回类型

bool

PySide2.QtCore.QUuid. __eq__ ( orig ) ¶

参数

orig – QUuid

返回类型

bool

PySide2.QtCore.QUuid. __gt__ ( other ) ¶

参数

other – QUuid

返回类型

bool

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()

PySide2.QtCore.QUuid. __ge__ ( rhs ) ¶

参数

rhs – QUuid

返回类型

bool

PySide2.QtCore.QUuid. toByteArray ( ) ¶

返回类型

QByteArray

Returns the binary representation of this QUuid . The byte array is formatted as five hex fields separated by ‘-‘ and enclosed in curly braces, i.e., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where ‘x’ is a hex digit. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

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

PySide2.QtCore.QUuid. toByteArray ( mode ) ¶

参数

mode – StringFormat

返回类型

QByteArray

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 as follows:

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

PySide2.QtCore.QUuid. toRfc4122 ( ) ¶

返回类型

QByteArray

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

PySide2.QtCore.QUuid. toString ( ) ¶

返回类型

unicode

Returns the string representation of this QUuid . The string is formatted as five hex fields separated by ‘-‘ and enclosed in curly braces, i.e., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where ‘x’ is a hex digit. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

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

PySide2.QtCore.QUuid. toString ( mode ) ¶

参数

mode – StringFormat

返回类型

unicode

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 as follows:

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

PySide2.QtCore.QUuid. variant ( ) ¶

返回类型

Variant

Returns the value in the variant field of the UUID. If the return value is 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()

PySide2.QtCore.QUuid. version ( ) ¶

返回类型

版本

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

另请参阅

variant()