QtNetwork:为什么我检测不到传入连接? (永远不会触发 incomingConnection())
QtNetwork: Why don't I detect incomming connections ? (incomingConnection() is never fired)
我坚持使用关于线程 qt-networking 的教程(在此处:http://doc.qt.io/qt-5/qtnetwork-threadedfortuneserver-example.html),我做了一些小改动并将其集成到我的主程序中。然而 incomingConnection()
永远不会被执行,另一方面 客户端能够 连接。因为我想使用 incomingConnection() 使用 SIGNAL(newConnection())
已经过时了,但即使这样也行不通。
有人知道出了什么问题吗?
这是我的.h
#include <QtNetwork>
#include <QTcpServer>
#include <QTcpSocket>
#include <QThread>
class WirelessNetThread: public Thread
{
Q_OBJECT
public:
WirelessNetThread(int socketDescriptor, QObject * parent);
void run() Q_DECL_OVERRIDE;
signals:
void error(QTcpSocket::SocketError socketError);
private:
int socketDescriptor;
QString text;
};
class WirelessNet : public QTcpServer
{
Q_OBJECT
public:
WirelessNet(QObject *parent = 0);
protected:
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
};
还有 .cpp
WirelessNetThread::WirelessNetThread(int socketDescriptor, QObject *parent):QThread(parent), socketDescriptor(socketDescriptor)
{
}
void WirelessNetThread::run()
{
QTcpSocket tcpSocket;
if ( !tcpSocket.setSocketDescriptor(socketDescriptor))
{
emit error(tcpSocket.error());
return;
}
tcpSocket.disconnectFromHost();
tcpSocket.waitForDisconnected();
}
WirelessNet::WirelessNet(QObject *parent): QTcpServer(0)
{
listen(QHostAddress::Any, 5220);
printf("is listening %d\n", this->isListening());
}
void WirelessNet::incomingConnection(qintptr socketDescriptor)
{
qDebug() << "incomming \n";
printf("incomming \n");
WirelessNetThread *thread = new WirelessNetThread(socketDescriptor, this);
connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
thread->start();
}
这里是我的主程序的摘录,它是从哪里启动的(顺便说一句,如果我省略 moveToThread():
也没关系
WirelessNet *wifi = new WirelessNet(this->parent());
wifi->moveToThread(this->thread());
如果我在 wifi 初始化后添加这些行,即使这样也没有影响:
wifi = new WirelessNet(this->parent());
QEventLoop testLoop;
testLoop.exec();
换句话说,"incomming" 永远不会打印出来,所以我无法继续工作。有没有人有想法,这几乎是 1:1 教程中的代码,这让我感到困惑。
在您的主要代码中:
WirelessNet *wifi = new WirelessNet(0); // 0 = assign no parent
QThread *wifiThread = new QThread;
wifi->moveToThread(wifiThread);
QObject::connect(wifiThread, SIGNAL(started()), wifi, SLOT(startWifi()));
// start() will start its own event loop, it will emit started(), therefore startWifi() slot will be called.
wifiThread->start();
那么你的 WirelessNet class header:
class WirelessNet : public QTcpServer
{
Q_OBJECT
public:
WirelessNet(QObject *parent = 0);
protected:
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
public slots:
void startWifi();
};
那么你的 WirelessNet class body:
WirelessNet::WirelessNet(QObject *parent) :
QTcpServer(parent)
{
// Do nothing much here because we want to initialise new stuff in our thread.
// When this function runs we have not moved this to the new thread - or even started it.
}
void WirelessNet::incomingConnection(qintptr socketDescriptor)
{
qDebug() << "incomming \n";
printf("incomming \n");
WirelessNetThread *thread = new WirelessNetThread(socketDescriptor, this);
connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
thread->start();
}
// Called when the thread has started
void WirelessNet::startWifi()
{
// Anything done here is now safely within out new thread.
listen(QHostAddress::Any, 5220);
printf("is listening %d\n", this->isListening());
}
注意这是示例代码,我直接写进了stack overflow 没有编译,所以可能有一些错误:)有一些关键点,我已评论,您可能在最初的尝试中出错了。
我坚持使用关于线程 qt-networking 的教程(在此处:http://doc.qt.io/qt-5/qtnetwork-threadedfortuneserver-example.html),我做了一些小改动并将其集成到我的主程序中。然而 incomingConnection()
永远不会被执行,另一方面 客户端能够 连接。因为我想使用 incomingConnection() 使用 SIGNAL(newConnection())
已经过时了,但即使这样也行不通。
有人知道出了什么问题吗?
这是我的.h
#include <QtNetwork>
#include <QTcpServer>
#include <QTcpSocket>
#include <QThread>
class WirelessNetThread: public Thread
{
Q_OBJECT
public:
WirelessNetThread(int socketDescriptor, QObject * parent);
void run() Q_DECL_OVERRIDE;
signals:
void error(QTcpSocket::SocketError socketError);
private:
int socketDescriptor;
QString text;
};
class WirelessNet : public QTcpServer
{
Q_OBJECT
public:
WirelessNet(QObject *parent = 0);
protected:
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
};
还有 .cpp
WirelessNetThread::WirelessNetThread(int socketDescriptor, QObject *parent):QThread(parent), socketDescriptor(socketDescriptor)
{
}
void WirelessNetThread::run()
{
QTcpSocket tcpSocket;
if ( !tcpSocket.setSocketDescriptor(socketDescriptor))
{
emit error(tcpSocket.error());
return;
}
tcpSocket.disconnectFromHost();
tcpSocket.waitForDisconnected();
}
WirelessNet::WirelessNet(QObject *parent): QTcpServer(0)
{
listen(QHostAddress::Any, 5220);
printf("is listening %d\n", this->isListening());
}
void WirelessNet::incomingConnection(qintptr socketDescriptor)
{
qDebug() << "incomming \n";
printf("incomming \n");
WirelessNetThread *thread = new WirelessNetThread(socketDescriptor, this);
connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
thread->start();
}
这里是我的主程序的摘录,它是从哪里启动的(顺便说一句,如果我省略 moveToThread():
也没关系WirelessNet *wifi = new WirelessNet(this->parent());
wifi->moveToThread(this->thread());
如果我在 wifi 初始化后添加这些行,即使这样也没有影响:
wifi = new WirelessNet(this->parent());
QEventLoop testLoop;
testLoop.exec();
换句话说,"incomming" 永远不会打印出来,所以我无法继续工作。有没有人有想法,这几乎是 1:1 教程中的代码,这让我感到困惑。
在您的主要代码中:
WirelessNet *wifi = new WirelessNet(0); // 0 = assign no parent
QThread *wifiThread = new QThread;
wifi->moveToThread(wifiThread);
QObject::connect(wifiThread, SIGNAL(started()), wifi, SLOT(startWifi()));
// start() will start its own event loop, it will emit started(), therefore startWifi() slot will be called.
wifiThread->start();
那么你的 WirelessNet class header:
class WirelessNet : public QTcpServer
{
Q_OBJECT
public:
WirelessNet(QObject *parent = 0);
protected:
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
public slots:
void startWifi();
};
那么你的 WirelessNet class body:
WirelessNet::WirelessNet(QObject *parent) :
QTcpServer(parent)
{
// Do nothing much here because we want to initialise new stuff in our thread.
// When this function runs we have not moved this to the new thread - or even started it.
}
void WirelessNet::incomingConnection(qintptr socketDescriptor)
{
qDebug() << "incomming \n";
printf("incomming \n");
WirelessNetThread *thread = new WirelessNetThread(socketDescriptor, this);
connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
thread->start();
}
// Called when the thread has started
void WirelessNet::startWifi()
{
// Anything done here is now safely within out new thread.
listen(QHostAddress::Any, 5220);
printf("is listening %d\n", this->isListening());
}
注意这是示例代码,我直接写进了stack overflow 没有编译,所以可能有一些错误:)有一些关键点,我已评论,您可能在最初的尝试中出错了。