在QT编程中有时会用到server服务端与客户端进行TCP网络通信，服务端部分代码如下：
1、创建server用于监听客户端套接字
this->server = new QTcpServer(this);
this->server->listen(QHostAddress::Any,);
connect(this->server,SIGNAL(newConnection()),this,SLOT(newConnection()));
2、newConnection()函数
//信号槽函数--新的设备连接
void Widget::newConnection()
{
//查询空闲的套接字
for(int i = ; i<SOCKET_MAXNUM; i++)
{
if(!this->socketFlag[i])
{
this->socketIndex = i;
break;
}
}
this->socket[socketIndex] = this->server->nextPendingConnection();
this->socketFlag[socketIndex] = SOCKET_FLAG_CONNECTED;
connect(this->socket[socketIndex],SIGNAL(readyRead()),this,SLOT(readData()));
scan_Device();
}
3、update_DeviceNetState()函数用于检测更新socket状态
//更新设备连接状态，清理释放过期的SOCKET
void Widget::update_DeviceNetState()
{
int onlineDeviceNum = getChildItemCount(DEVICE_TB_ONLINE_DEVICE);
qDebug()<<"Line-658 当前在线设备数量:"<<onlineDeviceNum;
for(int i = ;i<onlineDeviceNum;i++)
{
int socketID = ui->DEVICE_TABLE->topLevelItem(DEVICE_TB_ONLINE_DEVICE)->child(i)->data(,Qt::SocketIndex).toInt();
bool netState = send_WakeHand(socket[socketID]);
qDebug()<<"此设备在线? "<<netState;
if(netState == STATE_OFFLINE)
{
clearSocket(socketID);
deviceNetStateChange(i,DEVICE_TB_OFFLINE_DEVICE,DEVICE_TB_ONLINE_DEVICE,-);
}
}
}
4、send_WakeHand(QTcpSocket *currSocket) 发送握手信号返回套接字返回值
//发送握手信号，判断设备是否掉线
bool Widget::send_WakeHand(QTcpSocket *currSocket)
{
int ret = currSocket->write("wake hands");
qDebug()<<"ret ="<<ret;
if(ret == -)
return STATE_OFFLINE;
return STATE_ONLINE;
}
5、利用定时器QTimer定时检查更新套接字状态
QTimer *timer = new QTimer(this);
//定时检查更新设备的网络状态
connect(timer,SIGNAL(timeout()),this,SLOT(update_DeviceNetState()));
timer->start();
代码仅供学习参考，未经允许，禁止转载