server 是server = new QTcpServer(this);
newConnection()是QTcpServer的信号判断是否有新连接;
newConnectionSlot()是自己定义的一个槽
里面是不是这么写的
clientsocket = server->nextPendingConnection();
connect(clientsocket, SIGNAL(readyRead()), this, SLOT(readTCPMessageSlot()));
就是指定tcpsocket包为newConnection,if clientsocket readyRead() 就可以解码读tcpsocket包内容了