网络和连接
Qt 提供用于高级网络和低级网络两者通信的类、用于 Web 集成的类、及用于 IPC (进程间通信) 的类。
对于高级网络流量，
Qt Network
提供仅展示高级类和函数，覆盖所用操作的抽象层。Qt Network 还可以处理像 TCP 和 UDP 的低级协议。类
QTcpSocket
and
QUdpSocket
使开发者能够使用 TCP 或 UDP 协议发送和接收消息。名称解析的处理是采用
QHostInfo
.
QHostInfo
被调用，先于创建网络连接采用
QTcpSocket
or
QUdpSocket
。可以处理凭借代理过滤和重新分配网络流量，通过
QNetworkProxy
类。
Qt 提供
连接
选项以连接系统或应用程序使用模块，像
Qt Bluetooth
, which provides connectivity between Bluetooth enabled devices.
Qt Serial Bus
provides classes and functions to access the various industrial serial buses and protocols, and
Qt NFC
provides connectivity between NFC enabled devices. Also,
Qt Serial Port
provides the basic functionality, including configuring, I/O operations, and getting and setting the control signals of the RS-232 pinouts.
Qt 提供了功能为
进程间通信
。类
QProcess
被用于启动外部程序。
Qt D-Bus
provides support for D-Bus, an inter-process communication and remote procedure calling mechanism. It communicates via a central server application called a bus. However, it is also possible to let applications communicate directly with each other.
QSharedMemory
provides access to a shared memory segment by multiple threads and processes. However, a single process can exclusively lock that shared memory.
网络通信
Qt 支持广泛网络通信，重点是 HTTP、TCP 及 UDP。
在 HTTP 级别，
Qt Network
模块提供网络访问 API，主要包括
QNetworkRequest
,
QNetworkAccessManager
，和
QNetworkReply
。
QNetworkRequest
类似于 HTTP 请求，其被传递给
QNetworkAccessManager
以发送线上请求；此类返回
QNetworkReply
, which enables parsing the HTTP reply. The network access API internally uses the socket classes mentioned below (for TCP and SSL).
QTcpSocket
,
QUdpSocket
，和
QSslSocket
should be used for communication at the socket level. These classes offer a synchronous API through the waitFor* methods as well as an asynchronous API; if possible (that is if the event loop is running), the asynchronous API should always be preferred. Qt also offers
QTcpServer
to enable the server-side part of a TCP communication.
为凭借 SSL 进行安全通信，Qt Network 提供广泛的类，除了中心
QSslSocket
。例如，
QSslCertificate
,
QSslConfiguration
，和
QSslError
.
Qt 还在 QML 中提供 HTTP 支持，要么凭借 XmlHttpRequest 明确使用 HTTP，要么通过透明地使用 HTTP URL (例如：在图像源中)。
相关话题：
-
用 Qt 进行网络编程
-
SSL (安全套接字层) 类
-
资源加载和网络透明度
- 在 QML 中的网络和 URL 透明度
-
Qt Network Authorization
- set of APIs that enable Qt applications to obtain limited access to online accounts and HTTP services without exposing users' passwords.
-
Qt Remote Objects
- an inter-process communication (IPC) module that enables information exchange between processes or computers.
-
Qt MQTT
- machine-to-machine (M2M) protocol that uses the publish-and-subscribe paradigm to provide a channel with minimal communication overhead.
-
Qt OPC UA
- server that offers access to data that is organized in a mesh of nodes connected by references. The use of different reference types and nodes containing metadata enables a client to navigate and interpret the data without knowing their structure in advance.
-
Qt WebSockets
- web-based protocol designed to enable a two-way interactive communication session between a client application and a remote host. It enables the two entities to send data back and forth if the initial handshake succeeds.
-
Qt WebChannel
- enables peer-to-peer communication between a server (QML/C++ application) and a client (HTML/JavaScript or QML application). It is supported out of the box by Qt
WebEngine
. In addition, it can work on all browsers that support WebSockets, enabling Qt WebChannel clients to run in any JavaScript environment (including QML). This requires implementing a custom transport based on Qt WebSockets.
-
Qt Protobuf
- a generator that can be used to generate Qt-based classes from
.proto
文件。
-
Qt GRPC
- allows you to define data and messages in proto files and then use the code generators, which generate code allowing accessors for fields and gRPC services in the Qt framework.
连接
Qt 支持一系列连接选项，重点是
Qt Serial Bus
,
Qt Serial Port
,
Qt Bluetooth
and
Qt NFC
.
-
Qt Serial Bus
- provides classes and functions to access the various industrial serial buses and protocols, such as CAN, ModBus, and others.
-
Qt Serial Port
- provides the basic functionality, which includes configuring, I/O operations, getting and setting the control signals of the RS-232 pinouts.
-
Qt Bluetooth
- provides classes and functions to use Bluetooth devices, which includes scanning for devices, gathering information, and exchanging data between them. Qt Bluetooth supports both Classic and Low Energy Bluetooth technologies.
-
Qt NFC
- provides classes and functions to establish connectivity between NFC enabled devices. NFC is a short-range (less than 20 centimeters) wireless technology with a maximum transfer rate of 424 Kbps. NFC is ideal for transferring small packets of data when two devices are placed together.
相关话题：
