Qt TCP协议通信
码灵薯 人气:1TCP协议是经常使用的通信方式。在QT中做了非常友好的封装,使用非常方便。
需要添加的模块:network
Qt中的TCP类:QTcpSocket , QTcpServer
常用函数介绍
连接目标地址和端口
virtual void QTcpSocket ::connectToHost(const QHostAddress &address, quint16 port, OpenMode mode = ReadWrite);
- 发送数据
inline qint64 QTcpSocket ::write(const QByteArray &data)
- 监听某个地址和端口号
bool QTcpServer::listen(const QHostAddress &address = QHostAddress::Any, quint16 port = 0);
- 有新的连接信号
void QTcpServer::newConnection();
- 是否有新的连接
virtual bool QTcpServer::hasPendingConnections() const;
- 获取新的连接,必须处理完才能继续接收到连接
virtual QTcpSocket *QTcpServer::nextPendingConnection();
- 收到新的数据信号
void QTcpSocket::readyRead();
- 读取收到的数据,必须读取完才能继续接收
QByteArray readAll();
使用案例(example)
客户端
#include <QTcpSocket> #include <QWidget> #include <QLineEdit> class Client : public QWidget { Q_OBJECT public: Client(QWidget *parent); public slots: void slotSendButtonClick(); private: QTcpSocket *_socket; QLineEdit *_lineEdit; bool _isConnected; };
#include "client.h" #include <QPushButton> #include <QHBoxLayout> Client::Client(QWidget *parent) : QWidget(parent) { _socket = new QTcpSocket(this); _lineEdit = new QLineEdit(this); QPushButton *sendButton = new QPushButton("send"); connect(sendButton, SIGNAL(clicked()), this, SLOT(slotSendButtonClick())); connect(_lineEdit, SIGNAL(returnPressed()), this, SLOT(slotSendButtonClick())); QHBoxLayout *lay = new QHBoxLayout(this); lay->addWidget(_lineEdit); lay->addWidget(sendButton); _isConnected = false; } void Client::slotSendButtonClick() { if (!_isConnected) { _socket->connectToHost("127.0.0.1", 9988); _isConnected = true; } QString text = _lineEdit->text(); if (!text.isEmpty()) { _socket->write(text.toUtf8());//发送数据 _lineEdit->clear(); } }
服务端
#include <QWidget> #include <QTcpServer> #include <QTcpSocket> class QTextBrowser; class Server :public QWidget { Q_OBJECT public: Server(QWidget *parent); public slots: void slotCurrentIndexChanged(const QString&); void slotNewConnection(); private: QTcpServer *_server; QTcpSocket *_socket; QTextBrowser *_textBrowser; };
#include "server.h" #include <QHostAddress> #include <QTextBrowser> #include <QByteArray> #include <QGridLayout> #include <QNetworkInterface> #include <QComboBox> Server::Server(QWidget *parent) { _server = new QTcpServer(this); //_server->listen(QHostAddress::Any, 9988);//监听跟本主机相连的所有网口 connect(_server, SIGNAL(newConnection()),this, SLOT(slotNewConnection()) ); QList<QHostAddress> addrList = QNetworkInterface::allAddresses(); QComboBox *comboBox = new QComboBox; for (const QHostAddress& addr : addrList) { quint32 ipAddr = addr.toIPv4Address(); if (ipAddr != 0) { comboBox->addItem(QHostAddress(ipAddr).toString()); } } connect(comboBox, SIGNAL(currentIndexChanged(const QString&)), this, SLOT(slotCurrentIndexChanged(const QString&))); _textBrowser = new QTextBrowser(this); QGridLayout *lay = new QGridLayout(this); lay->addWidget(comboBox, 0, 0); lay->addWidget(_textBrowser,1,0); } void Server::slotCurrentIndexChanged(const QString& item) { if (!_server->isListening()) { _server->listen(QHostAddress(item), 9988); } _textBrowser->append("listen..."); } void Server::slotNewConnection() { _textBrowser->append("connecting..."); while (_server->hasPendingConnections())//必须处理完所有的连接,否则有新连接时就不会在发信号过来 { _socket = _server->nextPendingConnection(); connect(_socket, &QTcpSocket::readyRead, [&]() { _textBrowser->append("receive message..."); QByteArray newMessage = _socket->readAll(); _textBrowser->append(QString(newMessage)); }); } }
使用效果
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