QT5网络编程笔记 单客户端与多客户端

//QHostInfo类作用，获取主机名，也可以通过主机名来查找IP地址，或者通过IP地址来反向查找主机名。

QString localHostName = QHostInfo::localHostName();   //获取计算机名称

qDebug() << "LocalHostName:" << localHostName;

//获取IP地址

QHostInfo info = QHostInfo::fromName(localHostName);  //获取ip地址，包括ipv6

qDebug() << "IP Address:" << info.addresses();

foreach(QHostAddress address, info.addresses())  //取出IPv4地址

{

if (address.protocol() == QAbstractSocket::IPv4Protocol)

qDebug() << "IPv4 Address:" << address.toString();

ui->comboBox->addItem(address.toString());

}

foreach (QHostAddress address, QNetworkInterface::allAddresses())//去除所有地址包括127.0.0.1

{

qDebug() << "Address:" << address;

}

 服务器端设置：        QTcpserver QTcpsocket     QTcpserver主要负责监听端口，如果有链接 获得客户端套接字 if(ui->port->text().isEmpty())

   {

QMessageBox::about(this,tr("提示"),tr("端口没有设置"));

}

if(ui->listen->text() == tr("侦听"))

   {

//从输入框获取端口号

int port = ui->port->text().toInt();

//监听指定的端口

if(!m_tcpserver->listen(QHostAddress::Any, port))

   {

//若出错，则输出错误信息

qDebug()<<m_tcpserver->errorString();

return;

    }

qDebug()<< "Listen succeessfully!";

}

  当监听到链接时会产生newconnect()信号，然后创建客户端套接字 （这个是单客户端）//获取客户端连接

m_tcpsocket = m_tcpserver->nextPendingConnection();

//连接QTcpSocket的信号槽，以读取新数据

QObject::connect(m_tcpsocket, &QTcpSocket::readyRead, this, &MainWindow::socket_Read_Data);

QObject::connect(m_tcpsocket, &QTcpSocket::disconnected, this, &MainWindow::socket_Disconnected);

ui->show->append(m_tcpsocket->peerAddress().toString());  //获得客户端的ip地址

//发送按键使能

ui->send->setEnabled(true);

qDebug() << "A Client connect!";

将textedit的数据送到指定的客户端上， qDebug()<<"send:"<<ui->sendtext->toPlainText();

QByteArray datasend=ui->sendtext->toPlainText().toLocal8Bit();

m_tcpsocket->write(datasend);

m_tcpsocket->flush();

ui->sendtext->clear();

读取网络数据并解析：QByteArray requestData;

//读取缓冲区数据

requestData = m_tcpsocket->readAll();

if(requestData.at(0)==102)

{

twoBytes=requestData.mid(1,4); //

int j = twoBytes[3] & 0x000000ff;

j |= ((twoBytes[2] << 8) & 0x0000ff00);

j |= ((twoBytes[1] << 16) & 0x00ff0000);

j |= ((twoBytes[0] << 24) & 0xff000000);

twoBytes2=requestData.mid(5,4); //

int d = twoBytes2[3] & 0x000000ff;

d |= ((twoBytes2[2] << 8) & 0x0000ff00);

d |= ((twoBytes2[1] << 16) & 0x00ff0000);

d |= ((twoBytes2[0] << 24) & 0xff000000);

twoBytes3=requestData.mid(9,4);//

int m = twoBytes3[3] & 0x000000ff;

m |= ((twoBytes3[2] << 8) & 0x0000ff00);

m |= ((twoBytes3[1] << 16) & 0x00ff0000);

m |= ((twoBytes3[0] << 24) & 0xff000000);

twoBytes4=requestData.mid(13,4);//

union MyUnion

   {

unsigned char info[4];

float f;

    }FLOAT_DATA;

FLOAT_DATA.info[0]=twoBytes4[0];

FLOAT_DATA.info[1]=twoBytes4[1];

FLOAT_DATA.info[2]=twoBytes4[2];

FLOAT_DATA.info[3]=twoBytes4[3];

twoBytes5=requestData.mid(17,4);

union YouUnion

   {

unsigned char info[4];

float f;

    }FLOAT_DATA1;

FLOAT_DATA1.info[0]=twoBytes5[0];

FLOAT_DATA1.info[1]=twoBytes5[1];

FLOAT_DATA1.info[2]=twoBytes5[2];

FLOAT_DATA1.info[3]=twoBytes5[3];

  }

requestData.clear();    //清除缓冲区

多客户端与单客户端的区别在于产生newconnect()信号时的处理方式

m_tcpsocket = m_tcpserver->nextPendingConnection();

socket_list->append(m_tcpsocket); //定义一个QList<QTcpSocket>数据类型的对象，存储链接的客户端套接字信息。

//连接QTcpSocket的信号槽，以读取新数据

QObject::connect(m_tcpsocket, &QTcpSocket::readyRead, this, &MainWindow::socket_Read_Data);

QObject::connect(m_tcpsocket, &QTcpSocket::disconnected, this, &MainWindow::socket_Disconnected);

ui->show->append(m_tcpsocket->peerAddress().toString());

//发送按键使能

ui->send->setEnabled(true);

qDebug() << "A Client connect!";

多客户端解析数据时的方式QByteArray message;

for(int i = 0;i < socket_list->length();i ++)

{

message = socket_list->at(i)->readAll() ;

if(!message.isEmpty())

   {

qDebug()<< message;

    }