c – 如何使用QTcpSocket实例多次使用几秒间隔?
作者:互联网
我必须多次用QTcpSocket重复相同的请求,间隔几秒钟.
简单的任务,但我无法让它只与一个对象实例一起工作.如何使用相同的QTcpSocket实例再次连接到服务器?
我已经在许多不同的组合中尝试了reset(),resume(),flush(),open()并且它什么都没做.我无法第二次连接ToHost()……
解决方法:
您所要做的就是connectToHost(),使用连接,然后使用disconnectFromHost().而已.没有更多,没有更少.
以下示例说明了客户端和服务器套接字实例的重用.服务器实例保存在仅在必要时增长的池中.它是为Qt 5编写的并使用C 11.
// https://github.com/KubaO/stackoverflown/tree/master/questions/multisocket-22726075
#include <QtNetwork>
class EchoServer : public QTcpServer
{
QStack<QTcpSocket*> m_pool;
void incomingConnection(qintptr descr) Q_DECL_OVERRIDE {
if (m_pool.isEmpty()) {
auto s = new QTcpSocket(this);
QObject::connect(s, &QTcpSocket::readyRead, s, [s]{
s->write(s->readAll());
});
QObject::connect(s, &QTcpSocket::disconnected, this, [this, s]{
m_pool.push(s);
});
m_pool.push(s);
}
m_pool.pop()->setSocketDescriptor(descr, QTcpSocket::ConnectedState);
}
public:
~EchoServer() { qDebug() << "pool size:" << m_pool.size(); }
};
void setupEchoClient(QTcpSocket & sock)
{
static const char kByteCount[] = "byteCount";
QObject::connect(&sock, &QTcpSocket::connected, [&sock]{
auto byteCount = 64 + qrand() % 65536;
sock.setProperty(kByteCount, byteCount);
sock.write(QByteArray(byteCount, '\x2A'));
});
QObject::connect(&sock, &QTcpSocket::readyRead, [&sock]{
auto byteCount = sock.property(kByteCount).toInt();
if (byteCount) {
auto read = sock.read(sock.bytesAvailable()).size();
byteCount -= read;
}
if (byteCount <= 0) sock.disconnectFromHost();
sock.setProperty(kByteCount, byteCount);
});
}
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QHostAddress addr("127.0.0.1");
quint16 port = 5050;
EchoServer server;
if (! server.listen(addr, port)) qFatal("can't listen");
QTcpSocket clientSocket;
setupEchoClient(clientSocket);
auto connectsLeft = 20;
auto connector = [&clientSocket, &addr, port, &connectsLeft]{
if (connectsLeft--) {
qDebug() << "connecting" << connectsLeft;
clientSocket.connectToHost(addr, port);
} else
qApp->quit();
};
// reconnect upon disconnection
QObject::connect(&clientSocket, &QTcpSocket::disconnected, connector);
// initiate first connection
connector();
return a.exec();
}
标签:c,tcp,qt,qtcpsocket 来源: https://codeday.me/bug/20190929/1831892.html