Qt tcp 通信

#-------------------------------------------------

#

# Project created by QtCreator 2015-11-30T10:38:00

#

#-------------------------------------------------

QT       += core gui network

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = NCClien

TEMPLATE = app

SOURCES += main.cpp\

ncclien.cpp

HEADERS  += ncclien.h

FORMS    += ncclien.ui

ncclien.h

#ifndef NCCLIEN_H

#define NCCLIEN_H

#include <QMainWindow>

#include <QtNetwork>

namespace Ui {

class NCClien;

}

class NCClien : public QMainWindow

{

Q_OBJECT

public:

explicit NCClien(QWidget *parent = 0);

~NCClien();

private slots:

void displayError(QAbstractSocket::SocketError);

public:

QTcpSocket* tcpSocket;  //套接字发收控制

private slots:

void readMessage();

void sendMessage(QString str);

void on_Request_PButton_clicked();

void on_Send_PButton_clicked();

private:

quint16 blockSize;

QString message;

private:

Ui::NCClien *ui;

};

#endif // NCCLIEN_H

ncclien.cpp

#include "ncclien.h"

#include "ui_ncclien.h"

NCClien::NCClien(QWidget *parent) :

QMainWindow(parent),

ui(new Ui::NCClien)

{

ui->setupUi(this);

ui->IP_lineEdit->setText("127.0.0.1");

ui->Port_lineEdit->setText("6666");

tcpSocket = new QTcpSocket(this);

connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(readMessage()));

connect(tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)),

this, SLOT(displayError(QAbstractSocket::SocketError)));

blockSize = 0;

tcpSocket->abort();

}

void NCClien::readMessage()  //读取消息

{

QDataStream in(tcpSocket);

in.setVersion(QDataStream::Qt_5_4);

if(blockSize == 0)

{

if(tcpSocket->bytesAvailable() < (int)sizeof(quint16))

{

return;

}

in>>blockSize;

}

if(tcpSocket->bytesAvailable() < blockSize)

{

return;

}

in>>message;

//qDebug()<<message;  //输出消息

//    sendMessage("hello server!!");

ui->RecieveText->append(message);

blockSize = 0;

}

void NCClien::sendMessage(QString str)   //发送消息

{

QByteArray SendArray;

QDataStream out(&SendArray, QIODevice::WriteOnly);

out.setVersion(QDataStream::Qt_5_4);

out<<(qint16) 0;  //强制类型转换

out<<str;

out.device()->seek(0);  //游标跑到第一个位置处

out<<(quint16)(SendArray.size() - sizeof(quint16));

//我们获取已经建立的连接的子套接字

tcpSocket->write(SendArray);

}

void NCClien::displayError(QAbstractSocket::SocketError)

{

qDebug()<<tcpSocket->errorString();  //输出错误信息

}

void NCClien::on_Request_PButton_clicked()

{

tcpSocket->connectToHost(ui->IP_lineEdit->text(),

ui->Port_lineEdit->text().toInt());

}

void NCClien::on_Send_PButton_clicked()

{

sendMessage(ui->SendText->toPlainText());

ui->SendText->clear();

}

NCClien::~NCClien()

{

delete ui;

}

服务端代码：

NCServer.pro

#-------------------------------------------------

#

# Project created by QtCreator 2015-11-30T10:36:45

#

#-------------------------------------------------

QT       += core gui network

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = NCSever

TEMPLATE = app

SOURCES += main.cpp\

ncserver.cpp

HEADERS  += ncserver.h

FORMS    += ncserver.ui

NCServer.h

#ifndef NCSERVER_H

#define NCSERVER_H

#include <QMainWindow>

#include <QtNetwork>

#include <QIODevice>

#include <QMessageBox>

namespace Ui {

class NCServer;

}

class NCServer : public QMainWindow

{

Q_OBJECT

public:

explicit NCServer(QWidget *parent = 0);

~NCServer();

public:

QTcpServer* tcpServer;   //网络程序服务器端

QTcpSocket* tcpSocket;   //网络通信套接字发受部分

private:

quint16 blockSize;

bool b_connect;

private slots:

void sendMessage(QString str);

void CreateTcp();   //创建tcp对象

void readMessage();

void on_Listen_PButton_clicked();

void on_Send_PButton_clicked();

private:

Ui::NCServer *ui;

};

#endif // NCSERVER_H

NCServer.cpp

#include "ncserver.h"

#include "ui_ncserver.h"

NCServer::NCServer(QWidget *parent) :

QMainWindow(parent),

ui(new Ui::NCServer)

{

ui->setupUi(this);

ui->IP_lineEdit->setText("127.0.0.1");

ui->Port_lineEdit->setText("6666");

b_connect = false;

blockSize = 0;

tcpServer = new QTcpServer(this);

}

void NCServer::CreateTcp()

{

tcpSocket = tcpServer->nextPendingConnection();  //初始化tcp套接字的变量，此时开始套接字才可以使用

connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(readMessage()));  //绑定读取消息的基本操作

b_connect = true;  //表示已经连接起来

}

void NCServer::sendMessage(QString str)

{

if(b_connect)

{

    QByteArray SendArray;

    QDataStream out(&SendArray, QIODevice::WriteOnly);

out.setVersion(QDataStream::Qt_5_3);

    out<<(qint16) 0;  //强制类型转换

    out<<str;

    out.device()->seek(0);  //游标跑到第一个位置处

    out<<(quint16)(SendArray.size() - sizeof(quint16));

    //我们获取已经建立的连接的子套接字

    tcpSocket->write(SendArray);

}

else

{

QMessageBox::critical(this, tr("警告！！"), tr("断开状态请连接"), QMessageBox::Ok);

}

}

void NCServer::readMessage()

{

QString message;

QDataStream in(tcpSocket);

in.setVersion(QDataStream::Qt_5_4);

if(blockSize == 0)

{

if(tcpSocket->bytesAvailable() < (int)sizeof(quint16))

{

return;

}

in>>blockSize;

}

if(tcpSocket->bytesAvailable() < blockSize)

{

return;

}

in>>message;

qDebug()<<message;  //输出消息

ui->RecievText->append(message);

blockSize = 0;

}

void NCServer::on_Listen_PButton_clicked()  //开始监听

{

bool ListenOk = tcpServer->listen((QHostAddress)ui->IP_lineEdit->text(),

ui->Port_lineEdit->text().toUInt());

if(!ListenOk)  //如果监听出现错误

{

qDebug()<<tcpServer->errorString();

close();

}

connect(tcpServer, SIGNAL(newConnection()), this, SLOT(CreateTcp()));

}

void NCServer::on_Send_PButton_clicked()

{

sendMessage(ui->SendText->toPlainText());

ui->SendText->clear();

}

NCServer::~NCServer()

{

delete ui;

}