The QUuid class stores a Universally Unique Identifier (UUID). 更多...
| 头： | #include <QUuid> |
| qmake: | QT += core |
| 继承者： | QBluetoothUuid |
注意： 此类的所有函数 可重入 .
| enum | Variant { VarUnknown, NCS, DCE, Microsoft, Reserved } |
| enum | 版本 { VerUnknown, Time, EmbeddedPOSIX, Name, ..., Sha1 } |
| QUuid () | |
| QUuid (uint l , ushort w1 , ushort w2 , uchar b1 , uchar b2 , uchar b3 , uchar b4 , uchar b5 , uchar b6 , uchar b7 , uchar b8 ) | |
| QUuid (const QString & text ) | |
| QUuid (const QByteArray & text ) | |
| QUuid (const GUID & guid ) | |
| bool | isNull () const |
| QByteArray | toByteArray () const |
| CFUUIDRef | toCFUUID () const |
| NSUUID * | toNSUUID () const |
| QByteArray | toRfc4122 () const |
| QString | toString () const |
| QUuid::Variant | variant () const |
| QUuid::Version | version () const |
| 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 |
| 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 ) |
| QUuid | fromCFUUID (CFUUIDRef uuid ) |
| QUuid | fromNSUUID (const NSUUID * uuid ) |
| QUuid | fromRfc4122 (const QByteArray & bytes ) |
| uint | qHash (const QUuid & uuid , uint 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 ) |
The QUuid class stores a Universally Unique Identifier (UUID).
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
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 ().
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 | 值 | 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 |
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 | 值 | 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
|
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} QUuid IID_MyInterface(0x67c8770b, 0x44f1, 0x410a, 0xab, 0x9a, 0xf9, 0xb5, 0x44, 0x6f, 0x13, 0xee);
创建 QUuid object from the string text , which must be formatted as five hex fields separated by '-', e.g., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where '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 .
创建 QUuid 对象从 QByteArray text , which must be formatted as five hex fields separated by '-', e.g., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where '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 toByteArray () for an explanation of how the five hex fields map to the public data members in QUuid .
该函数在 Qt 4.8 引入。
另请参阅 toByteArray () 和 QUuid ().
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 . If the /dev/urandom device exists, then the numbers used to construct the UUID will be of cryptographic quality, which will make the UUID unique. Otherwise, the numbers of the UUID will be obtained from the local pseudo-random number generator ( qrand (), which is seeded by qsrand ()) which is usually not of cryptograhic quality, which means that the UUID can't be guaranteed to be unique.
On a Windows platform, a GUID is generated, which almost certainly will be unique, on this or any other system, networked or not.
[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.
该函数在 Qt 5.0 引入。
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.
该函数在 Qt 5.0 引入。
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.
该函数在 Qt 5.0 引入。
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.
该函数在 Qt 5.0 引入。
另请参阅 variant (), version ()，和 createUuidV3 ().
[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.
该函数在 Qt 5.7 引入。
[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.
该函数在 Qt 5.7 引入。
[static]
QUuid
QUuid::
fromRfc4122
(const
QByteArray
&
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.
该函数在 Qt 4.8 引入。
返回
true
if this is the null UUID {00000000-0000-0000-0000-000000000000}; otherwise returns
false
.
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 如下：
| Field # | 源 |
|---|---|
| 1 | data1 |
| 2 | data2 |
| 3 | data3 |
| 4 | data4[0] .. data4[1] |
| 5 | data4[2] .. data4[7] |
该函数在 Qt 4.8 引入。
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.
该函数在 Qt 5.7 引入。
Creates a NSUUID from a QUuid . The NSUUID is autoreleased.
注意： this function is only available on Apple platforms.
该函数在 Qt 5.7 引入。
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 # | 源 |
|---|---|
| 1 | data1 |
| 2 | data2 |
| 3 | data3 |
| 4 | data4[0] .. data4[7] |
该函数在 Qt 4.8 引入。
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 如下：
| Field # | 源 |
|---|---|
| 1 | data1 |
| 2 | data2 |
| 3 | data3 |
| 4 | data4[0] .. data4[1] |
| 5 | data4[2] .. data4[7] |
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 ().
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 ().
Returns a Windows GUID from a QUuid .
警告： This function is only for Windows platforms.
返回
true
若此
QUuid
和
other
QUuid
are different; otherwise returns
false
.
返回
true
if this UUID is not equal to the Windows GUID
guid
；否则返回
false
.
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 ().
Assigns a Windows guid to a Qt QUuid .
警告： This function is only for Windows platforms.
返回
true
若此
QUuid
和
other
QUuid
are identical; otherwise returns
false
.
返回
true
if this UUID is equal to the Windows GUID
guid
；否则返回
false
.
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 ().
Returns a hash of the UUID uuid ，使用 seed 做计算种子。
该函数在 Qt 5.0 引入。
Writes the UUID id 到数据流 s .
Writes the UUID id to the output stream for debugging information dbg .
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
.
该函数在 Qt 5.5 引入。
另请参阅 variant ().
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
.
该函数在 Qt 5.5 引入。
另请参阅 variant ().
Reads a UUID from the stream s into id .