tcp服务器端与多个客户端连接

如果希望Tcp服务器端可以与多个客户端连接，可以这样写：

    tcpServer=new QTcpServer(this);
    connect(tcpServer,SIGNAL(newConnection()),this,SLOT(onNewConnection()));

void MainWindow::onNewConnection()
{
    QTcpSocket *tcpSocket;//TCP通讯的Socket
    tcpSocket = tcpServer->nextPendingConnection(); //创建socket
    qDebug()<<"tcpSocket:"<<tcpSocket;
    connect(tcpSocket, SIGNAL(connected()),
            this, SLOT(onClientConnected()));
    emit tcpSocket->connected();

    connect(tcpSocket, SIGNAL(disconnected()),
            this, SLOT(onClientDisconnected()));

    connect(tcpSocket,SIGNAL(stateChanged(QAbstractSocket::SocketState)),
            this,SLOT(onSocketStateChange(QAbstractSocket::SocketState)));
    emit tcpSocket->stateChanged(tcpSocket->state());

    connect(tcpSocket,SIGNAL(readyRead()),
            this,SLOT(onSocketReadyRead()));
}

相关的槽函数中：

void MainWindow::onClientConnected()
{//客户端接入时
    QTcpSocket* tcpSocket=(QTcpSocket*)sender();
    ui->plainTextEdit->appendPlainText("**client socket connected");
    ui->plainTextEdit->appendPlainText("**peer address:"+
                                   tcpSocket->peerAddress().toString());
    ui->plainTextEdit->appendPlainText("**peer port:"+
                                   QString::number(tcpSocket->peerPort()));
}

使用sender()来获取对应的QTcpSocket对象。

其实，主要就是QTcpServer进行监听：

客户端的QTcpSocket与服务器端的QTcpSocket进行通信。