qt学习之路六（QT的tcp传输）

来源：互联网发布：泡泡是什么聊天软件编辑：程序博客网时间：2024/05/06 02:41

　　这几天一直在做银行的管理系统，包括职工的登陆注册以及客户的开户转账存取款等功能，这几天天天通宵也写的差不多了，还剩下最后一个功能，交易记录的管理，差不多明天应该就能结束了。

　　这两天为了做这个东西，我把qt的网络模块初学了一下，学了一下qt的tcp传输，实现了服务器与客户端的通信。但是，在做的时候，我本来是打算做一个循环并发的服务器，但测试了一下后，突然发现，这个服务器根本不用开线程，它一直在工作，在一个客户端连接后，它就通过信号与槽函数，直接去处理，处理完后再返回，这样做，在连接数少的时候，确实和并发服务器差不多，但是做一个假设，假设有1000多台客户端连接的话，瞬间崩溃了，但我也不懂在哪边开线程合适，Linux中的话服务器在连接到后就应该开辟线程，但是qt中服务器在得到连接后直接去处理槽函数了，所以想了很久，还是不懂在哪边开辟线程，最终还是没有做出来，不过几十台的话处理起来应该没有什么问题（安慰自己。。）。

下面的代码（没有开线程）：

/********************************************************************************** Form generated from reading UI file 'client.ui'**** Created: Thu Feb 16 16:09:39 2017**      by: Qt User Interface Compiler version 4.8.1**** WARNING! All changes made in this file will be lost when recompiling UI file!********************************************************************************/#ifndef UI_CLIENT_H#define UI_CLIENT_H#include <QtCore/QVariant>#include <QtGui/QAction>#include <QtGui/QApplication>#include <QtGui/QButtonGroup>#include <QtGui/QDialog>#include <QtGui/QHeaderView>#include <QtGui/QLabel>#include <QtGui/QLineEdit>#include <QtGui/QPushButton>QT_BEGIN_NAMESPACEclass Ui_client{public:    QLabel *label;    QLabel *label_2;    QLabel *messagelabel;    QLineEdit *hostlineEdit;    QLineEdit *portlineEdit;    QPushButton *connect;    void setupUi(QDialog *client)    {        if (client->objectName().isEmpty())            client->setObjectName(QString::fromUtf8("client"));        client->resize(400, 300);        label = new QLabel(client);        label->setObjectName(QString::fromUtf8("label"));        label->setGeometry(QRect(60, 70, 71, 31));        label_2 = new QLabel(client);        label_2->setObjectName(QString::fromUtf8("label_2"));        label_2->setGeometry(QRect(60, 130, 71, 31));        messagelabel = new QLabel(client);        messagelabel->setObjectName(QString::fromUtf8("messagelabel"));        messagelabel->setGeometry(QRect(80, 190, 171, 61));        hostlineEdit = new QLineEdit(client);        hostlineEdit->setObjectName(QString::fromUtf8("hostlineEdit"));        hostlineEdit->setGeometry(QRect(130, 80, 113, 20));        portlineEdit = new QLineEdit(client);        portlineEdit->setObjectName(QString::fromUtf8("portlineEdit"));        portlineEdit->setGeometry(QRect(130, 140, 113, 20));        connect = new QPushButton(client);        connect->setObjectName(QString::fromUtf8("connect"));        connect->setGeometry(QRect(260, 240, 75, 23));        retranslateUi(client);        QMetaObject::connectSlotsByName(client);    } // setupUi    void retranslateUi(QDialog *client)    {        client->setWindowTitle(QApplication::translate("client", "client", 0, QApplication::UnicodeUTF8));        label->setText(QApplication::translate("client", "\344\270\273\346\234\272", 0, QApplication::UnicodeUTF8));        label_2->setText(QApplication::translate("client", "\347\253\257\345\217\243", 0, QApplication::UnicodeUTF8));        messagelabel->setText(QApplication::translate("client", "\346\216\245\346\224\266\345\210\260\347\232\204\344\277\241\346\201\257", 0, QApplication::UnicodeUTF8));        connect->setText(QApplication::translate("client", "\350\277\236\346\216\245", 0, QApplication::UnicodeUTF8));    } // retranslateUi};namespace Ui {    class client: public Ui_client {};} // namespace UiQT_END_NAMESPACE#endif // UI_CLIENT_H

#ifndef CLIENT_H#define CLIENT_H#include <QDialog>#include <QAbstractSocket>#include <QTcpSocket>#include <QString>namespace Ui {class client;}class client : public QDialog{    Q_OBJECT    public:    explicit client(QWidget *parent = 0);    ~client();    private:    Ui::client *ui;    QTcpSocket *tcpsocket;    QString  message;    quint16 blocksize;private slots:    void newconnect();    void readmessage();    void displayreeoe(QAbstractSocket::SocketError);    void on_connect_clicked();};#endif // CLIENT_H

#include "client.h"#include "ui_client.h"#include <QtNetwork>client::client(QWidget *parent) :    QDialog(parent),    ui(new Ui::client){    ui->setupUi(this);    tcpsocket = new QTcpSocket(this);    connect(tcpsocket, SIGNAL(readyRead()), this, SLOT(readmessage()));    connect(tcpsocket, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(displayreeoe(QAbstractSocket::SocketError)));}client::~client(){    delete ui;}void client::newconnect(){    blocksize = 0;    tcpsocket->abort();    tcpsocket->connectToHost(ui->hostlineEdit->text(), ui->portlineEdit->text().toInt());}void client::readmessage(){    QDataStream in(tcpsocket);    in.setVersion(QDataStream::Qt_4_6);    if(blocksize == 0)    {        if(tcpsocket->bytesAvailable() < (int)sizeof(quint16))        {            return;        }        in>>blocksize;    }    if(tcpsocket->bytesAvailable() < blocksize)    {        return;    }    in>>message;    ui->messagelabel->setText(message);}void client::displayreeoe(QAbstractSocket::SocketError){    qDebug()<<tcpsocket->errorString();}void client::on_connect_clicked(){    newconnect();}

#include <QtGui/QApplication>#include "client.h"int main(int argc, char *argv[]){    QApplication a(argc, argv);    client w;    w.show();        return a.exec();}

/********************************************************************************** Form generated from reading UI file 'server.ui'**** Created: Thu Feb 16 15:41:59 2017**      by: Qt User Interface Compiler version 4.8.1**** WARNING! All changes made in this file will be lost when recompiling UI file!********************************************************************************/#ifndef UI_SERVER_H#define UI_SERVER_H#include <QtCore/QVariant>#include <QtGui/QAction>#include <QtGui/QApplication>#include <QtGui/QButtonGroup>#include <QtGui/QDialog>#include <QtGui/QHeaderView>#include <QtGui/QLabel>QT_BEGIN_NAMESPACEclass Ui_server{public:    QLabel *label;    void setupUi(QDialog *server)    {        if (server->objectName().isEmpty())            server->setObjectName(QString::fromUtf8("server"));        server->resize(400, 300);        label = new QLabel(server);        label->setObjectName(QString::fromUtf8("label"));        label->setGeometry(QRect(70, 40, 121, 61));        retranslateUi(server);        QMetaObject::connectSlotsByName(server);    } // setupUi    void retranslateUi(QDialog *server)    {        server->setWindowTitle(QApplication::translate("server", "server", 0, QApplication::UnicodeUTF8));        label->setText(QApplication::translate("server", "\347\255\211\345\276\205\350\277\236\346\216\245....", 0, QApplication::UnicodeUTF8));    } // retranslateUi};namespace Ui {    class server: public Ui_server {};} // namespace UiQT_END_NAMESPACE#endif // UI_SERVER_H

#ifndef SERVER_H#define SERVER_H#include <QDialog>#include <QTcpServer>namespace Ui {class server;}class server : public QDialog{    Q_OBJECT    public:    explicit server(QWidget *parent = 0);    ~server();    private:    Ui::server *ui;    QTcpServer *tcp_server;public slots:    void sendmassage();};#endif // SERVER_H

#include "server.h"#include "ui_server.h"#include <QtNetwork>server::server(QWidget *parent) :    QDialog(parent),    ui(new Ui::server){    ui->setupUi(this);    tcp_server = new QTcpServer(this);    if(! tcp_server->listen(QHostAddress::LocalHost, 6666))    {        qDebug()<<tcp_server->errorString();        close();    }    connect(tcp_server, SIGNAL(newConnection()), this, SLOT(sendmassage()));}server::~server(){    delete ui;}void server::sendmassage(){    QByteArray block;    QDataStream out(&block, QIODevice::WriteOnly);    out.setVersion(QDataStream::Qt_4_0);    out<<(quint16)0;    out<<tr("hello tcp!!!");    out.device()->seek(0);    out<<(quint16)(block.size()-sizeof(quint16));    QTcpSocket *cfd = tcp_server->nextPendingConnection();    connect(cfd, SIGNAL(disconnected()), cfd, SLOT(deleteLater()));    cfd->write(block);    cfd->disconnectFromHost();    ui->label->setText("send message successful!");}

#include <QtGui/QApplication>#include "server.h"int main(int argc, char *argv[]){    QApplication a(argc, argv);    server w;    w.show();        return a.exec();}

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