最近要用到Qt的Socket部分，网上关于这部分的资料都比较复杂，我在这总结一下，把Socket的主要部分提取出来，实现TCP和UDP的简单通信。
UDP没有特定的server端和client端，简单来说就是向特定的ip发送报文，因此我把它分为发送端和接收端。 注意：在.pro文件中要添加QT += network，否则无法使用Qt的网络功能。
1 #include <QtNetwork> 2 QUdpSocket *sender; 3 sender = new QUdpSocket(this); 4 QByteArray datagram = “hello world!”; 5 //UDP广播 6 sender->writeDatagram(datagram.data(),datagram.size(),QHostAddress::Broadcast,6665); 7 //向特定IP发送 8 QHostAddress serverAddress = QHostAddress("10.21.11.66"); 9 sender->writeDatagram(datagram.data(), datagram.size(),serverAddress, 6665); 10 /* writeDatagram函数原型，发送成功返回字节数，否则-1 11 qint64 writeDatagram(const char *data,qint64 size,const QHostAddress &address,quint16 port) 12 qint64 writeDatagram(const QByteArray &datagram,const QHostAddress &host,quint16 port) 13 */
1 #include <QtNetwork> 2 QUdpSocket *receiver; 3 //信号槽 4 private slots: 5 void readPendingDatagrams(); 6 receiver = new QUdpSocket(this); 7 receiver->bind(QHostAddress::LocalHost, 6665); 8 connect(receiver, SIGNAL(readyRead()),this, SLOT(readPendingDatagrams())); 9 void readPendingDatagrams() 10 { 11 while (receiver->hasPendingDatagrams()) { 12 QByteArray datagram; 13 datagram.resize(receiver->pendingDatagramSize()); 14 receiver->readDatagram(datagram.data(), datagram.size()); 15 //数据接收在datagram里 16 /* readDatagram 函数原型 17 qint64 readDatagram(char *data,qint64 maxSize,QHostAddress *address=0,quint16 *port=0) 18 */ 19 } 20 }
TCP的话要复杂点，必须先建立连接才能传输数据，分为server端和client端。
1 #include <QtNetwork> 2 QTcpSocket *client; 3 char *data="hello qt!"; 4 client = new QTcpSocket(this); 5 client->connectToHost(QHostAddress("10.21.11.66"), 6665); 6 client->write(data);
1 #include <QtNetwork> 2 QTcpServer *server; 3 QTcpSocket *clientConnection; 4 server = new QTcpServer(); 5 server->listen(QHostAddress::Any, 6665); 6 connect(server, SIGNAL(newConnection()), this, SLOT(acceptConnection())); 7 void acceptConnection() 8 { 9 clientConnection = server->nextPendingConnection(); 10 connect(clientConnection, SIGNAL(readyRead()), this, SLOT(readClient())); 11 } 12 void readClient() 13 { 14 QString str = clientConnection->readAll(); 15 //或者 16 char buf[1024]; 17 clientConnection->read(buf,1024); 18 }
原文：http://www.cnblogs.com/suanec/p/4102555.html