我在使用QTcpSocket和线程时遇到了一些问题。
我想我误解了有关Threads的文档，也许你可以解释我的错误所在。什么部分应该进入run()方法，当发出信号并连接到线程类的插槽时，它在哪里接收？在＆＃34; base＆＃34;中，不在run()中，对吧？那么我如何通知＆＃34;运行＆＃34;部分是否有必要做的事情？共享对象？怎么样？
我最终要归档的内容如下：
+-----------------------+
| Server |
| keeps some global |
| objects |
+--X----------------X---+
X X
+---------------X---+ +--X----------------+
| | | |
| Thread for Client | | Thread for Client |
| B | | A |
| keeps local data | | keeps local data |
+-----------X-------+ +-----------X-------+
X X
X X
+---------X----+ +--------X-----+
| Socket | | Socket |
+-------+---+--+ +----+---+-----+
^ | | ^
| | ---------------- | |
| | Network | |
| | --------------- | |
| | | | +----------------+
| | | | | |
| | | +-------+ Client A |
| | | | |
| | +---------->+----------------+
| |
| | +----------------+
| +------------------------------------->+ |
| | Client B |
+------------------------------------------+ |
+----------------+
下面添加的代码工作提供＆＃34; QSocketNotifie r：无法从另一个线程启用或禁用套接字通知程序＆＃34;。我之前的方法（这里没有代码）给出了＃34; QObject：无法为不同线程中的父级创建子级。＆＃34;。我也读过了Events-Threads-Objects wiki文章（https://wiki.qt.io/Threads_Events_QObjects），但我想我有些混淆了。
我需要在此处更改，客户端A可以将数据发送到服务器，服务器更改数据并将答案传递给客户端A和B（我将在实际应用程序中为套接字设置keep-alive选项，但出于简化原因将其留在这里）。所有＆＃34;客户＆＃34; （他们的线程）必须能够从服务器读取和修改对象。这样做的最佳方法是什么？我想我应该在这里使用信号和插槽，并且autoconnection应该足够好（如果通知所有线程立即发送数据，我很好，我的协议中有reciever个id，所以我可以在调用write()之前检查是否应该丢弃该消息。
server.pro：
QT += network
QT += core
HEADERS = \
server.h \
clientthread.h
SOURCES = \
main.cpp \
server.cpp \
clientthread.cpp
clietthead.h：
#ifndef CTHREAD_H
#define CHREAD_H
#include <QThread>
#include <QTcpSocket>
class ClientThread : public QThread {
Q_OBJECT
public:
ClientThread(int socketDescriptor, QObject *parent);
void run() Q_DECL_OVERRIDE;
QTcpSocket * tcpSocket;
public slots:
void slot_msg_answer();
void slot_request_msg_FromServer();
signals:
void error(QTcpSocket::SocketError socketError);
void signal_for_Server_request_msg();
private:
int socketDescriptor;
};
#endif
server.h
#ifndef SERVER_H
#define SERVER_H
#include <QTcpServer>
class Server : public QTcpServer {
Q_OBJECT
signals:
void signalFor_PT_msg_answert(QString);
public:
Server(QObject *parent = 0);
public slots:
void slot_request_msg();
protected:
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
private:
};
#endif
clientthread.cpp
#include "clientthread.h"
#include <QTcpSocket>
#include <QtNetwork>
ClientThread::ClientThread(int socketDescriptor, QObject *parent)
: QThread(parent), socketDescriptor(socketDescriptor) {
}
void ClientThread::slot_request_msg_FromServer() {
emit signal_for_Server_request_msg();
}
void ClientThread::run() {
tcpSocket = new QTcpSocket();
tcpSocket->setSocketOption(QAbstractSocket::KeepAliveOption, true);
if (!tcpSocket->setSocketDescriptor(socketDescriptor)) {
emit error(tcpSocket->error());
return;
}
QByteArray ba ( "foo");
tcpSocket->write(ba);
tcpSocket->flush();
exec();
}
void ClientThread::slot_msg_answer() {
QByteArray ba ("bar");
tcpSocket->write(ba);
tcpSocket->flush();
}
的main.cpp
#include <QtCore>
#include "server.h"
int main(int argc, char *argv[]) {
QCoreApplication app(argc, argv);
Server server_;
if (!server_.listen(QHostAddress::Any, 1234)) {
qDebug() << "unable to start the server";
return -1;
}
return app.exec();
}
server.cpp
#include "server.h"
#include "clientthread.h"
#include <QTimer>
Server::Server(QObject *parent) : QTcpServer(parent) {
}
void Server::slot_request_msg() {
emit signalFor_PT_msg_answert("hello");
}
void Server::incomingConnection(qintptr socketDescriptor) {
ClientThread *thread = new ClientThread(socketDescriptor, this);
connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));
connect(this, &Server::signalFor_PT_msg_answert, thread , &ClientThread::slot_msg_answer);
connect(thread, &ClientThread::signal_for_Server_request_msg, this, &Server::slot_request_msg);
thread->start();
QTimer *timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), thread, SLOT(slot_msg_answer()));
timer->start(2000);
}
以上所有代码均基于Qt的线程财富服务器示例，该示例属于bsd许可证：
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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****************************************************************************/
答案 0 :(得分：1)
您的线程对象有插槽。
那些插槽将在＆＃34;拥有＆＃34;的线程的上下文中被调用。除非Qt::DirectConnection强制调用发出信号的线程中的对象。
您的ClientThread个对象拥有＆＃34;拥有＆＃34;由主threadm（它执行类的构造函数）。
如果要在运行客户端连接的线程中调用这些槽，则必须将对象移动到该线程中。
这意味着在您的情况下，最好的选择是不要从QThread派生，而是将您的客户端处理程序创建为QObject子类，并简单地＆＃34;移动＆＃34;它是一个新的QThread个实例，请参阅QObject::moveToThread()
作为奖励点，您可以在不涉及任何辅助线程的情况下对此进行测试。