client.cpp
#include "widget.h"
#include "ui_widget.h"
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
tcpSocket = new QTcpSocket(this);
connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(readMessage()));
connect(tcpSocket,SIGNAL(error(QAbstractSocket::SocketError)),
this,SLOT(displayError(QAbstractSocket::SocketError)));
connect(ui->pushButton,SIGNAL(clicked()),this,SLOT(on_pushButton_clicked()));
}
Widget::~Widget()
{
delete ui;
}
void Widget::newConnect()
{
blockSize = 0; //初始化其为0
tcpSocket->abort(); //取消已有的连接
/* tcpSocket->connectToHost(ui->hostLineEdit->text(),
ui->portLineEdit->text().toInt());*/
tcpSocket->connectToHost("192.168.1.24",6666);
//连接到主机，这里从界面获取主机地址和端口号
}
void Widget::readMessage()
{
QDataStream in(tcpSocket);
in.setVersion(QDataStream::Qt_4_7);
//设置数据流版本，这里要和服务器端相同
if(blockSize==0) //如果是刚开始接收数据
{
//判断接收的数据是否有两字节，也就是文件的大小信息
//如果有则保存到blockSize变量中，没有则返回，继续接收数据
if(tcpSocket->bytesAvailable() < (int)sizeof(quint16)) return;
in >> blockSize;
}
if(tcpSocket->bytesAvailable() < blockSize) return;
//如果没有得到全部的数据，则返回，继续接收数据
in >> message;
//将接收到的数据存放到变量中
ui->messageLabel->setText(message);
//显示接收到的数据
}
void Widget::displayError(QAbstractSocket::SocketError)
{
qDebug() << tcpSocket->errorString(); //输出错误信息
}
void Widget::on_pushButton_clicked() //连接按钮
{
newConnect(); //请求连接
}
server.cpp
#include "widget.h"
#include "ui_widget.h"
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
tcpServer = new QTcpServer(this);
if(!tcpServer->listen(QHostAddress::LocalHost,6666))
{ //监听本地主机的6666端口，如果出错就输出错误信息，并关闭
qDebug() << tcpServer->errorString();
close();
}
connect(tcpServer,SIGNAL(newConnection()),this,SLOT(sendMessage()));
}
Widget::~Widget()
{
delete ui;
}
void Widget::sendMessage()
{
QByteArray block; //用于暂存我们要发送的数据
QDataStream out(&block,QIODevice::WriteOnly);
//使用数据流写入数据
out.setVersion(QDataStream::Qt_4_7);
//设置数据流的版本，客户端和服务器端使用的版本要相同
out<<(quint16) 0;
out<<tr("hello Tcp!!!");
out.device()->seek(0);
out<<(quint16)(block.size()-sizeof(quint16));
QTcpSocket *clientConnection = tcpServer->nextPendingConnection();
//我们获取已经建立的连接的子套接字
connect(clientConnection,SIGNAL(disconnected()),clientConnection,
SLOT(deleteLater()));
clientConnection->write(block);
clientConnection->disconnectFromHost();
ui->statusLabel->setText("send message successful!!!");