QThread *thread;
thread=new QThread(this);
qDebug()<<"1:"<<commUdpClient->thread();
commUdpClient->moveToThread(thread);
thread->start();
qDebug()<<"2:"<<commUdpClient->thread();

//CommUdpClient.h#include <QObject>
#include <QUdpSocket>class CommUdpClient : public QObject
{Q_OBJECT
public:explicit CommUdpClient(QObject *parent = 0);~CommUdpClient();QUdpSocket *socket;　　 QUdpSocket *socket2;     QUdpSocket socket3;private:QHostAddress serverAddress;quint16 serverPort;public://发送报文void send(const QByteArray &msg);signals://接收完报文后触发的信号，用于上层触发相应的槽，获得报文void sigRevedMsg(QByteArray msg,const QStringList &paras);public slots://报文发送完成信号bytesWritten对应的槽void sltSent(qint64 bytes);//接收报文,对应信号readyRead的槽
    QByteArray sltReceive();//通讯参数设置,打开连接void sltOpenConnect(const QStringList &paras);}; 

#include "commudpclient.h"
#include <qstringlist.h>
#include <QMetaEnum>
#include <QDebug>
#include <QThread>CommUdpClient::CommUdpClient(QObject *parent) :QObject(parent)
{qDebug()<<"udp current thread 1:"<<QThread::currentThread();//错误//socket=new QUdpSocket;//connect(socket,SIGNAL(bytesWritten(qint64)),this,SLOT(sltSent(qint64)));//connect(socket,SIGNAL(readyRead()),this,SLOT(sltReceive()));　　socket2=new QUdpSocket;　　 qDebug()<<"socket2 thread:"<<socket2->thread();
}CommUdpClient::~CommUdpClient()
{if(socket!=NULL){if(socket->isOpen()){socket->close();}delete socket;socket=NULL;}
}void CommUdpClient::sltOpenConnect(const QStringList &paras)
{qDebug()<<"udp current thread 2:"<<QThread::currentThread();//正确socket=new QUdpSocket();//这里加this和不加this是有区别的这是打印出来的socket的parent，是有区别的，不过这里的CommUdpClient也是顶层的，无parent的，不然是无法移动到子线程中的，会报错，具体在对象B的源码中描述。

    connect(socket,SIGNAL(bytesWritten(qint64)),this,SLOT(sltSent(qint64)));connect(socket,SIGNAL(readyRead()),this,SLOT(sltReceive()));
　　//测试　　qDebug()<<"socket thread:"<<socket->thread();　　qDebug()<<"socket2 thread:"<<socket2->thread();　　qDebug()<<"scoket3 thread:"<<socket3.thread();　　qDebug()<<this<<", thread:"<<this->thread();

serverAddress.setAddress(paras[0]);serverPort=paras[1].toUShort();socket->bind(paras[2].toUShort());
}void CommUdpClient::send(const QByteArray &msg)
{　　qDebug()<<"udp send thread:"<<QThread::currentThread();if(!serverAddress.isNull()){socket->writeDatagram(msg,serverAddress,serverPort);qDebug()<<"client send end";}
}void CommUdpClient::sltSent(qint64 bytes)
{}QByteArray CommUdpClient::sltReceive()
{qDebug()<<"server start receive...";while (socket->hasPendingDatagrams()) {QByteArray datagram;datagram.resize(socket->pendingDatagramSize());QHostAddress sender;quint16 senderPort;socket->readDatagram(datagram.data(), datagram.size(),&sender, &senderPort);qDebug()<<datagram;QStringList sl;sl.append(sender.toString());sl.append(QString::number(senderPort));emit sigRevedMsg(datagram,sl);return datagram;}
}

#ifndef COMMUNICATION_H
#define COMMUNICATION_H#include <QObject>
#include <QThread>
#include <qstringlist.h>
#include "commtcpclient.h"class Communication : public QObject
{Q_OBJECT
public:explicit Communication(QObject *parent = 0);virtual ~Communication();public:CommUdpClient *commUdpClient;QThread *thread;public:void readData();void writeData();signals:void sigThreadConnect(const QStringList &paras);public slots:void sltRevedMsg(QByteArray msg,const QStringList &paras);};#endif // COMMUNICATION_H

#include "communication.h"
#include <QCoreApplication>
#include <QDebug>
#include <QTime>Communication::Communication(QObject *parent) :QObject(parent)
{qDebug()<<"current thread:"<<QThread::currentThread();commUdpClient=new CommUdpClient();//这里不能加this，不然是不允许移到子线程中，报错

    connect(commUdpClient,SIGNAL(sigRevedMsg(QByteArray,QStringList)),this,SLOT(sltRevedMsg(QByteArray,QStringList)));connect(this,SIGNAL(sigThreadConnect(QStringList)),commUdpClient,SLOT(sltOpenConnect(QStringList)));thread=new QThread(this);　　 qDebug()<<"1:"<<commUdpClient->thread();commUdpClient->moveToThread(thread);    qDebug()<<"2:"<<commUdpClient->thread();    thread->start();    qDebug()<<"3:"<<commUdpClient->thread();
}Communication::~Communication()
{delete commUdpClient;thread->quit();delete thread;
}void Communication::readData()
{QString sz="192.168.1.186:1234:1235";QStringList sl=sz.split(':');emit sigThreadConnect(sl);//正确用法

    //commUdpClient->send("error");//不正确的用法，这个是直接在对象B的线程中运行的

}void Communication::writeData()
{qDebug()<<"xxxx";
}void Communication::sltRevedMsg(QByteArray msg)
{qDebug()<<"communication end,receive msg:"<<msg;
}void Communication::sltRevedMsg(QByteArray msg, const QStringList &paras)
{

}

class TcpComm:public QThread
{Q_OBJECT
public:TcpComm(const QString &iAddrStr, quint16 iPort);~TcpComm();........
private: .......TcpClient*mTcpClient;
};TcpComm::TcpComm(const QString &iAddrStr, quint16 iPort):mAddr(iAddrStr), mPort(iPort)
{mIsStop = false;mTcpClient = new TcpClient();start();
}
以上程序在运行时报QObject: Cannot create children for a parent that is in a different thread错误。
将原构造函数中的mTcpClient = new TcpClient();放到run()中问题解决。
TcpComm::TcpComm(const QString &iAddrStr, quint16 iPort):mAddr(iAddrStr), mPort(iPort)
{mIsStop = false;start();
}void TcpComm::run()
{mTcpClient = new TcpClient();........
}
查了查，原因应该是，在QThread中定义的所有东西都属于创建该QThread的线程。所以在构造函数中初始化的mTcpClient应该是属于父线程的，那么在run中调用时就属于跨线程调用。所以把mTcpClient放到run中初始化就属于线程的了，调用时就不会出现跨线程调用的问题。另外：QThread中写的所有函数都应该在创建它的线程中调用,而不是开启QThread的线程