Qt中使用Tcp构建通信客户端实现聊天信息发送连接等
1.简介2.项目创建和界面构建1）流程图2）项目构建3）界面构建3.代码设计1）项目pro添加2）客户端设计a. clientwidget.hb.clientwdige.cpp3）服务端设计a.serverwidget.hb.serverwidget.cpp4.源代码附录clientwidget.hclientwidget.cppserverwidget.hserverwidget.cpp5.源文件下载1.简介
TCP通信协议是面向对象，可靠的连接服务，正因为这是它最大的特点，因此在诸多领域应用广泛，在使用Qt进行面向对象的设计的时候，也常常用到TCP通信，而在Qt中，TCP协议被封装成了一个更易调用的类。此篇博文将使用Qt中的TCP通信来实现客户端和服务端的连接交互通信，以此作为延伸。 在之前的一篇博文中 ，Linux中C语言构建TCP通信，使用了C语言对TCP协议进行调用，来实现客户端和服务端的通信连接。而Qt中的TCP通信连接步骤和C语言中原生tcp连接的步骤一样，大体都是分为以下大类
创建套接字绑定本机地址和端口设置监听套接字主动向服务器（客户端）发送请求客户端（服务器）接受连接请求接受/发送数据（双方）关闭套接字
区别在于，Qt中调用TCP的方式简单，可以实现如下的效果
以下是详细的实际实现
2.项目创建和界面构建
1）流程图
TCP协议通信逻辑图有下图，根据此逻辑图，可以更好的理解Qt中的TCP协议的调用
2）项目构建
创建widget项目，除自有界面外，再添加一个新的界面，构建如下图所示的项目文件树
3）界面构建
客户端界面构建
服务端界面构建
两个界面大体是构建上面是显示消息栏。下面是输入消息发送栏。
3.代码设计
1）项目pro添加
第一步需要在项目的pro文件中添加网络通信模块
QT += network
2）客户端设计
a. clientwidget.h
首先需要添加所需头文件，用于tcp通信
#include <QTcpSocket>
之后是tcp通信的类的声明以及一个相应键盘事件的事件过滤器
private:QTcpSocket *tcpSocket;protected:bool eventFilter(QObject *target, QEvent *event);//事件过滤器};
b.clientwdige.cpp
同样是添加所需工具头文件
#include <QHostAddress>#include <QDebug>#include <QTime>#include <QKeyEvent>
之后是构造函数和部分相关函数的设计
ClientWidget::ClientWidget(QWidget *parent) :QWidget(parent),ui(new Ui::ClientWidget){ui->setupUi(this);this->setWindowTitle("客户端");this->resize(500,300);this->setMinimumSize(500,300);tcpSocket = new QTcpSocket(this);connect(tcpSocket,&QTcpSocket::connected,[=](){ui->textEditRead->setText("与服务器成功连接");qDebug() << "连接成功";});connect(tcpSocket,&QTcpSocket::readyRead,[=](){QByteArray array = tcpSocket->readAll();ui->textEditRead->append(array);});ui->ButtonSend->setFocus();ui->ButtonSend->setDefault(true);//ui->ButtonSend->setShortcut(Qt::Key_Enter|Qt::Key_Return);ui->textEditWrite->installEventFilter(this);//设置完后自动调用其eventFilter函数}ClientWidget::~ClientWidget(){delete ui;}void ClientWidget::on_ButtonConnect_clicked(){//获取服务器端口和ipQString ip = ui->lineEditIp->text();qint16 port = ui->lineEditPort->text().toInt();//与服务器进行连接tcpSocket->connectToHost(QHostAddress(ip),port);}void ClientWidget::on_ButtonSend_clicked(){//获取编辑框内容QTime cur_time = QTime::currentTime();QString str = ui->textEditWrite->toPlainText();QString time_info = cur_time.toString("hh:mm:ss");QString str_info = QString("客户端: %1 [%2]").arg(str).arg(time_info);//发送数据tcpSocket->write(str_info.toUtf8().data());ui->textEditWrite->clear();//ui->textEditWrite->setFocus();}void ClientWidget::on_ButtonClose_clicked(){//主动断开连接tcpSocket->disconnectFromHost();ui->textEditRead->setText("与服务器断开连接!");tcpSocket->close();}
3）服务端设计
a.serverwidget.h
添加头文件
#include <QTcpServer> //监听套接字#include <QTcpSocket> //通信套接字
通信套接字声明实现和事件过滤器
private:QTcpServer *tcpServer;QTcpSocket *tcpSocket;protected:bool eventFilter(QObject *target, QEvent *event);//事件过滤器
b.serverwidget.cpp
添加工具头文件
#include <QTime>#include <QKeyEvent>
构造函数设计
ServerWidget::ServerWidget(QWidget *parent) :QWidget(parent),ui(new Ui::ServerWidget){ui->setupUi(this);tcpServer = NULL;tcpSocket = NULL;//tcpServer = new QTcpServer(this);tcpSocket = new QTcpSocket(this);tcpServer->listen(QHostAddress::Any,8888);this->setWindowTitle("服务器(端口:8888)");this->resize(500,300);this->setMinimumSize(500,300);connect(tcpServer,&QTcpServer::newConnection,[=](){//取出建立好连接的套接字tcpSocket = tcpServer->nextPendingConnection();//获取对方的ip和端口sstatic QString ip = tcpSocket->peerAddress().toString();static qint16 port = tcpSocket->peerPort();QString temp = QString("[%1:%2] : 成功连接").arg(ip).arg(port);ui->textEditRead->setText(temp);connect(tcpSocket,&QTcpSocket::readyRead,[=](){//从通信套接字中取出内容QByteArray array = tcpSocket->readAll();ui->textEditRead->append(array); //追加添加内容});});// connect(tcpSocket,&QTcpSocket::readyRead,// [=]()// {////从通信套接字中取出内容//QByteArray array = tcpSocket->readAll();//ui->textEditRead->append(array); //追加添加内容// }// );ui->ButtonSend->setFocus();ui->ButtonSend->setDefault(true);//ui->ButtonSend->setShortcut(Qt::Key_Enter|Qt::Key_Return);ui->textEditWrite->installEventFilter(this);//设置完后自动调用其eventFilter函数}
经此设计构建之后可以实现如上的功能操作，有此基础之后可以自定定义自己的服务器，如智能小车的控制，摄像头图像的传递识别等等
4.源代码附录
clientwidget.h
#ifndef CLIENTWIDGET_H#define CLIENTWIDGET_H#include <QWidget>#include <QTcpSocket>namespace Ui {class ClientWidget;}class ClientWidget : public QWidget{Q_OBJECTpublic:explicit ClientWidget(QWidget *parent = nullptr);~ClientWidget();private slots:void on_ButtonSend_clicked();void on_ButtonConnect_clicked();void on_ButtonClose_clicked();private:Ui::ClientWidget *ui;private:QTcpSocket *tcpSocket;protected:bool eventFilter(QObject *target, QEvent *event);//事件过滤器};#endif // CLIENTWIDGET_H
clientwidget.cpp
#include "clientwidget.h"#include "ui_clientwidget.h"#include <QHostAddress>#include <QDebug>#include <QTime>#include <QKeyEvent>ClientWidget::ClientWidget(QWidget *parent) :QWidget(parent),ui(new Ui::ClientWidget){ui->setupUi(this);this->setWindowTitle("客户端");this->resize(500,300);this->setMinimumSize(500,300);tcpSocket = new QTcpSocket(this);connect(tcpSocket,&QTcpSocket::connected,[=](){ui->textEditRead->setText("与服务器成功连接");qDebug() << "连接成功";});connect(tcpSocket,&QTcpSocket::readyRead,[=](){QByteArray array = tcpSocket->readAll();ui->textEditRead->append(array);});ui->ButtonSend->setFocus();ui->ButtonSend->setDefault(true);//ui->ButtonSend->setShortcut(Qt::Key_Enter|Qt::Key_Return);ui->textEditWrite->installEventFilter(this);//设置完后自动调用其eventFilter函数}ClientWidget::~ClientWidget(){delete ui;}void ClientWidget::on_ButtonConnect_clicked(){//获取服务器端口和ipQString ip = ui->lineEditIp->text();qint16 port = ui->lineEditPort->text().toInt();//与服务器进行连接tcpSocket->connectToHost(QHostAddress(ip),port);}void ClientWidget::on_ButtonSend_clicked(){//获取编辑框内容QTime cur_time = QTime::currentTime();QString str = ui->textEditWrite->toPlainText();QString time_info = cur_time.toString("hh:mm:ss");QString str_info = QString("客户端: %1 [%2]").arg(str).arg(time_info);//发送数据tcpSocket->write(str_info.toUtf8().data());ui->textEditWrite->clear();//ui->textEditWrite->setFocus();}void ClientWidget::on_ButtonClose_clicked(){//主动断开连接tcpSocket->disconnectFromHost();ui->textEditRead->setText("与服务器断开连接!");tcpSocket->close();}bool ClientWidget::eventFilter(QObject *target, QEvent *event){if(target == ui->textEditWrite){if(event->type() == QEvent::KeyPress)//回车键{QKeyEvent *k = static_cast<QKeyEvent *>(event);if(k->key() == Qt::Key_Return){on_ButtonSend_clicked();return true;}}}return QWidget::eventFilter(target,event);}
serverwidget.h
#ifndef SERVERWIDGET_H#define SERVERWIDGET_H#include <QWidget>#include <QTcpServer> //监听套接字#include <QTcpSocket> //通信套接字namespace Ui {class ServerWidget;}class ServerWidget : public QWidget{Q_OBJECTpublic:explicit ServerWidget(QWidget *parent = nullptr);~ServerWidget();protected:bool eventFilter(QObject *target, QEvent *event);//事件过滤器private slots:void on_ButtonClose_clicked();void on_ButtonSend_clicked();private:Ui::ServerWidget *ui;private:QTcpServer *tcpServer;QTcpSocket *tcpSocket;// QString ip;// qint16 port;};#endif // SERVERWIDGET_H
serverwidget.cpp
#include "serverwidget.h"#include "ui_serverwidget.h"#include <QTime>#include <QKeyEvent>ServerWidget::ServerWidget(QWidget *parent) :QWidget(parent),ui(new Ui::ServerWidget){ui->setupUi(this);tcpServer = NULL;tcpSocket = NULL;//tcpServer = new QTcpServer(this);tcpSocket = new QTcpSocket(this);tcpServer->listen(QHostAddress::Any,8888);this->setWindowTitle("服务器(端口:8888)");this->resize(500,300);this->setMinimumSize(500,300);connect(tcpServer,&QTcpServer::newConnection,[=](){//取出建立好连接的套接字tcpSocket = tcpServer->nextPendingConnection();//获取对方的ip和端口sstatic QString ip = tcpSocket->peerAddress().toString();static qint16 port = tcpSocket->peerPort();QString temp = QString("[%1:%2] : 成功连接").arg(ip).arg(port);ui->textEditRead->setText(temp);connect(tcpSocket,&QTcpSocket::readyRead,[=](){//从通信套接字中取出内容QByteArray array = tcpSocket->readAll();ui->textEditRead->append(array); //追加添加内容});});// connect(tcpSocket,&QTcpSocket::readyRead,// [=]()// {////从通信套接字中取出内容//QByteArray array = tcpSocket->readAll();//ui->textEditRead->append(array); //追加添加内容// }// );ui->ButtonSend->setFocus();ui->ButtonSend->setDefault(true);//ui->ButtonSend->setShortcut(Qt::Key_Enter|Qt::Key_Return);ui->textEditWrite->installEventFilter(this);//设置完后自动调用其eventFilter函数}ServerWidget::~ServerWidget(){delete ui;}bool ServerWidget::eventFilter(QObject *target, QEvent *event){if(target == ui->textEditWrite){if(event->type() == QEvent::KeyPress)//回车键{QKeyEvent *k = static_cast<QKeyEvent *>(event);if(k->key() == Qt::Key_Return){on_ButtonSend_clicked();return true;}}}return QWidget::eventFilter(target,event);}void ServerWidget::on_ButtonSend_clicked(){if(tcpSocket == NULL){return ;}//获取编辑区内容QTime cur_time = QTime::currentTime();QString str = ui->textEditWrite->toPlainText();QString time_info = cur_time.toString("hh:mm:ss");QString str_info = QString("服务器: %1 [%2]").arg(str).arg(time_info);tcpSocket->write(str_info.toUtf8().data());ui->textEditWrite->clear();}void ServerWidget::on_ButtonClose_clicked(){if(tcpSocket == NULL)//主动与客户端断开连接tcpSocket->disconnectFromHost();static QString ip = tcpSocket->peerAddress().toString();static qint16 port = tcpSocket->peerPort();QString showtemp = QString("[%1:%2] : 断开连接").arg(ip).arg(port);ui->textEditRead->setText(showtemp);tcpSocket->close();//this->close();tcpSocket = NULL;}
5.源文件下载
详细效果，可戳传送门下载体验传送门
