我是完全复制书上的程序的，虽然能运行成功了，但是代码中有几个地方不明白。。求求解。。
我不知道该怎么表达我想问的问题，只好把所有的程序粘贴出来，然后加些注释。。。
程序如下：
#ifndef SERVER_H
#define SERVER_H
#include <QtNetwork>
#include "tcpclientsocket.h"
class Server : public QTcpServer
{
Q_OBJECT
public:
Server(QObject *parent = 0,int port=0);
QList<TcpClientSocket*> tcpClientSocketList;
//这个尖括号代表什么意思？？
signals:
void updateServer(QString,int);
public slots:
void updateClients(QString,int);
void slotDisconnected(int);
protected:
void incomingConnection(int socketDescriptor);
};
#endif
#include "server.h"
Server::Server(QObject *parent,int port)
:QTcpServer(parent)
{
listen(QHostAddress::Any,port);
}
void Server::incomingConnection(int socketDescriptor)
{
TcpClientSocket *tcpClientSocket = new TcpClientSocket(this);
connect(tcpClientSocket,SIGNAL(updateClients(QString,int)),this,SLOT(updateClients(QString,int)));
//上面的那个为什么信号和槽是一样的？？
connect(tcpClientSocket,SIGNAL(disconnected(int)) ,this,SLOT(slotDisconnected(int)));
tcpClientSocket->setSocketDescriptor(socketDescriptor);
tcpClientSocketList.append(tcpClientSocket);
}
void Server::updateClients(QString msg, int length)
{
emit updateServer(msg,length);//没有函数定义，那它怎么成为信号的？？
for(int i = 0;i < tcpClientSocketList.count();i++)
{
QTcpSocket *item = tcpClientSocketList.at(i);
if(item->write(msg.toLatin1(),length) != length)//这句有什么用，我觉得没啥用好像多余的
{ //直接item->write(msg.toLatin1(),length)不就行了吗？？
continue;
}
}
}
void Server::slotDisconnected(int descriptor)
{
for(int i = 0;i < tcpClientSocketList.count();i++)
{
QTcpSocket *item = tcpClientSocketList.at(i);
if(item->socketDescriptor() == descriptor)
{
tcpClientSocketList.removeAt(i);
continue;
}
}