这里直接上代码：(工程文件在我的资源中：QT 之 TCP/IP 服务器和客户端（数据流出流入操作版本）链接：http://download.csdn.net/download/zhaoyuaiweide/9960458

操作很简单，都是最基本的一些调用，作为基础都总结在这里啦！

client.h

#ifndef TCPCLIENT_H
#define TCPCLIENT_H

#include <QMainWindow>
#include "QtNetwork"

namespace Ui {
class tcpclient;
}

class tcpclient : public QMainWindow
{
    Q_OBJECT

public:
    explicit tcpclient(QWidget *parent = 0);
    ~tcpclient();
    void sendMessage();

private slots:
    void tcpConnect();

    void receiveMessage();

    void displayError(QAbstractSocket::SocketError);  //显示错误

    void on_pushButton_clicked();

    void on_pushButton_2_clicked();

private:
    Ui::tcpclient   *ui;

    QTcpSocket      *client;

    quint8          m_rec[7];


    QByteArray      m_recByte;

    quint8           m_blocksize;



};

#endif // TCPCLIENT_H

client.cpp

#include "tcpclient.h"
#include "ui_tcpclient.h"
#include "qdebug.h"
#include <QDataStream>


tcpclient::tcpclient(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::tcpclient)
{
    ui->setupUi(this);

    m_blocksize = 0;

    client = new QTcpSocket(this);

    connect(client,SIGNAL(readyRead()),this,SLOT(receiveMessage()));

    connect(client,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(displayError(QAbstractSocket::SocketError)));
}

tcpclient::~tcpclient()
{
    delete ui;
}


void tcpclient::tcpConnect()
{
    //取消所有连接
    client->abort();
    //连接客户端
    client->connectToHost(ui->IPlineEdit->text(),ui->PortlineEdit->text().toInt());
}


//接收数据
void tcpclient::receiveMessage()
{
    QDataStream in(client);
    in.setVersion(QDataStream::Qt_5_5);

    m_blocksize = 0;

    if(m_blocksize == 0)
    {
        if(client->bytesAvailable() < sizeof(quint8))
        {
            return;
        }
        in>>m_blocksize;
    }

    if(client->bytesAvailable() < m_blocksize)
    {
        return;
    }

    m_recByte.clear();

    m_recByte.resize(m_blocksize);

    for(int i = 0;i<5;i++)
    {
        in>>m_rec[i];

        m_recByte[i]  = m_rec[i];
    }
    qDebug()<<"接收："<<m_recByte.toHex()<<endl;

}


//发送数据
void tcpclient::sendMessage()
{
    QByteArray mm_block;
    QDataStream out(&mm_block,QIODevice::WriteOnly);
    out.setVersion(QDataStream::Qt_5_5);

    out<<(quint8)0;
    out<<(quint8)0x01;
    out<<(quint8)0x02;
    out<<(quint8)0x03;
    out<<(quint8)0x04;
    out<<(quint8)0x05;

    out.device()->seek(0);
    out<<(quint8)(mm_block.size()-sizeof(quint8));

    qDebug()<<mm_block.size()<<"  "<<mm_block.toHex()<<endl;

    client->write(mm_block);
}

void tcpclient::displayError(QAbstractSocket::SocketError)
{
    qDebug()<<client->errorString();
}

//连接按钮
void tcpclient::on_pushButton_clicked()
{
    this->tcpConnect();
}

//发送消息按钮
void tcpclient::on_pushButton_2_clicked()
{
    sendMessage();

}

#ifndef TCPSERVER_H
#define TCPSERVER_H

#include <QMainWindow>
#include <QtNetwork>

namespace Ui {
class tcpserver;
}

class tcpserver : public QMainWindow
{
    Q_OBJECT

public:
    explicit tcpserver(QWidget *parent = 0);
    ~tcpserver();

private slots:
    void sendMessage();
    void receiveMessage();
    void successful();
    void on_pushButton_clicked();

private:
    Ui::tcpserver *ui;

    QTcpServer *server;

    QTcpSocket *client;

    QByteArray      m_recByte;

    quint8          m_rec[7];

    quint8          m_blocksize;
};

#endif // TCPSERVER_H

#include "tcpserver.h"
#include "ui_tcpserver.h"
#include <QDebug>


tcpserver::tcpserver(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::tcpserver)
{
    ui->setupUi(this);

    server = new QTcpServer(this);

    m_blocksize = 0;

    if(!server->listen(QHostAddress::Any,8001))//如果要监听本机地址：QHostAddress::LocalHost
    {
        qDebug()<<server->errorString();
        //监听本地主机的6666端口，如果出错就输出错误信息，并关闭
        close();
    }

    connect(server,SIGNAL(newConnection()),this,SLOT(successful()));
}

tcpserver::~tcpserver()
{
    delete ui;
}


void tcpserver::successful()
{
    ui->sendlabel->setText("successful");
    //获取连接客户端的套接字
    client = server->nextPendingConnection();
    //服务器等待接收数据
    connect(client,SIGNAL(readyRead()),this,SLOT(receiveMessage()));
}

//发送数据
void tcpserver::sendMessage()
{
    QByteArray mm_block;
    QDataStream out(&mm_block,QIODevice::WriteOnly);
    out.setVersion(QDataStream::Qt_5_5);

    out<<(quint8)0;
    out<<(quint8)0x01;
    out<<(quint8)0x02;
    out<<(quint8)0x03;
    out<<(quint8)0x04;
    out<<(quint8)0x05;

    out.device()->seek(0);
    out<<(quint8)(mm_block.size()-sizeof(quint8));

    qDebug()<<mm_block.size()<<"  "<<mm_block.toHex()<<endl;

    client->write(mm_block);

}


//接收数据
void tcpserver::receiveMessage()
{
    QDataStream in(client);
    in.setVersion(QDataStream::Qt_5_5);

    m_blocksize = 0;

    if(m_blocksize == 0)
    {
        if(client->bytesAvailable() < sizeof(quint8))
        {
            return;
        }
        in>>m_blocksize;
    }

    if(client->bytesAvailable() < m_blocksize)
    {
        return;
    }

    m_recByte.clear();

    m_recByte.resize(m_blocksize);

    for(int i = 0;i<5;i++)
    {
        in>>m_rec[i];

        m_recByte[i]  = m_rec[i];
    }
    qDebug()<<"接收："<<m_recByte.toHex()<<endl;

}

//按键
void tcpserver::on_pushButton_clicked()
{
    sendMessage();
}