QUuid
QUuid
#include <QUuid>
Public Types
| enum | StringFormat { WithBraces, WithoutBraces, Id128 } |
| enum | Variant { VarUnknown, NCS, DCE, Microsoft, Reserved } |
| enum | Version { VerUnknown, Time, EmbeddedPOSIX, Name, ..., Sha1 } |
Public Functions
| 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 |
| QByteArray | toByteArray(QUuid::StringFormat mode) const |
| CFUUIDRef | toCFUUID() const |
| NSUUID * | toNSUUID() const |
| QByteArray | toRfc4122() const |
| QString | toString() const |
| QString | toString(QUuid::StringFormat mode) 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 |
Static Public Members
| 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) |
| QUuid | fromString(QStringView text) |
| QUuid | fromString(QLatin1String text) |
Related Non-Members
| 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) |
详细说明
QUuid类存储一个通用唯一标识符（UUID）。
使用通用唯一标识符（UUID）是在分布式计算环境中唯一标识实体的标准方法。UUID是由某种算法生成的16字节（128位）数字，旨在保证UUID在使用它的分布式计算环境中是唯一的。缩写GUID通常被用来代替全局唯一标识符，但它指的是同一件事。
实际上，GUID是UUID的一种变体。多种变体正在使用中。每个UUID都包含一个位字段，该字段指定它是哪种类型的UUID（变体）。调用variant（）可以发现QUuid实例包含哪种UUID类型。它提取16个字节中字节8的三个最高有效位。在QUuid中，字节8是QUuid:：data4[0]。如果使用接受所有数值作为参数的构造函数创建QUuid的实例，请使用下表设置参数b1的三个最高有效位，该参数变为QUuid:：data4[0]，并在其三个最有效位中包含变量字段。在表中，“x”表示不在乎。
| 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 |
如果variant（）返回QUuid:：DCE，则UUID在QUuid：：data3的四个最高有效位中也包含一个版本字段，您可以调用version（）来发现您的QUuid包含哪个版本。如果使用接受所有数值作为参数的构造函数创建QUuid的实例，请使用下表设置参数w2的四个最高有效位，该参数将变为QUuid:：data3，并在其四个最有效位中包含版本字段。
| msb0 | msb1 | msb2 | msb3 | Version |
|---|---|---|---|---|
| 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 |
上表中列出的DCE版本的字段布局在网络工作组UUID规范中指定。
大多数平台都提供了生成新UUID的工具，例如uuidgen和guidgen。您也可以使用createUuid（）。createUuid（）生成的UUID属于随机类型。它们的QUuid:：Version位设置为QUuid：：Random，而它们的QUuid：：Variant位设置为Quid:：DCE。UUID的其余部分由随机数组成。从理论上讲，这意味着createUuid（）生成的UUID不唯一的可能性很小。但这是一个非常小的机会。
UUID可以由数值或字符串构造，也可以使用静态createUuid（）函数。可以使用toString（）将它们转换为字符串。UUID有一个variant（）和一个version（），null UUID从isNull（）返回true。
toString（StringFormat）使用此枚举来控制字符串表示形式的格式。可能的值为：
| Constant | Value | Description |
|---|---|---|
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.
| Constant | Value | Description |
|---|---|---|
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::Version
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.
| Constant | Value | Description |
|---|---|---|
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 |
Member Function Documentation
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