我创建了一个包含QTcpServer
的线程,它接受任何传入的连接:
void Service::run() //Service class is a subclass of QThread
{
server->listen(QHostAddress::LocalHost, ServicePortNo);
// server is a private member of Service
while(server->waitForNewConnection(-1)){
QTcpSocket *socket = server->nextPendingConnection();
handle(socket); // This is a pure virtual function
}
}
在 handle(QTcpSocket *socket)
中:
// TimeDateService is subclass of Service
// implementation of pure virtual function handle()
void TimeDateService::handle(QTcpSocket *socket)
{
(new TimeDateSocketHandler(socket))->Start();
}
注意:TimeDateSocketHandler
是SocketHandler
的子类,SocketHandler
本身是QThread的子类
如下图:
void SocketHandler::run()
{
if(!socket->waitForReadyRead(WAIT_TIMEOUT))
{
socket->disconnectFromHost();
socket->close();
return;
}
QByteArray request = socket->readAll();
QByteArray response = Serve(request); // Serve is a pure virtual function
socket->write(response);
socket->waitForBytesWritten(WAIT_TIMEOUT);
socket->disconnectFromHost();
socket->close();
}
最后是 TimeDateSocketHandler
QByteArray TimeDateSocketHandler::Serve(QByteArray request)
{
QByteArray response;
response.append(QTime::currentTime().toString().toUtf8());
response.append(QString(SEPARATOR).toUtf8());
response.append(QDate::currentDate().toString().toUtf8());
return response;
}
主要功能:
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
TimeDateService timedateService;
//CalculatorService calculatorService;
//RemoteCMDService remoteCMDService;
timedateService.StartService();
//calculatorService.StartService();
//remoteCMDService.StartService();
return a.exec();
}
在 main
函数中,我启动了 TimeDateService
。但是,当我连接到服务器以检索时间和日期时,服务器会发送时间和日期,但是当 TimeDateSocketHandler
想要关闭套接字时,程序崩溃了:
ASSERT failure in QCoreApplication::sendEvent: "Cannot send events to objects ow ned by a different thread. Current thread 3998779bf0. Receiver '' (of type 'QNat iveSocketEngine') was created in thread 39985efcd0", file kernel\qcoreapplicatio n.cpp, line 494
谁能帮我解决这个问题,非常感谢
最佳答案
你的问题是这一行:
(new TimeDateSocketHandler(socket))->Start();
父“套接字”位于 TimeDateService 线程中,但子“套接字”位于 TimeDateocketHandler 线程中。使用 Qt 事件循环时父子应该在同一个线程中。
这里是 documentation 的相关部分:
Event filters are supported in all threads, with the restriction that the monitoring object must live in the same thread as the monitored object. Similarly, QCoreApplication::sendEvent() (unlike postEvent()) can only be used to dispatch events to objects living in the thread from which the function is called. Here is an example of that:
解决方案相对简单:
您可以直接使用 invokeMethod method of QMetaObject 调用该方法.您需要使用排队连接来在单独的线程中触发插槽。
QMetaObject::invokeMethod(new TimeDateSocketHandler(socket), 插槽(开始()), Qt::QueuedConnection);
或
使用信号和槽。这意味着发出一个信号而不是直接调用,然后连接另一个线程的相应插槽。
TimeDateSocketHandler *timeDateSocketHandler = new TimeDateSocketHandler(socket);
connect(this, SIGNAL(socketHandled()), timeDateSocketHandler, SLOT(Start()));
发出 socketHandled();
或
使用智能指针(如 QSharedPointer)代替原始指针
将套接字处理移至另一个线程。
关于c++ - 从另一个线程(子线程)访问QTcpSocket,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21086256/