libevent服务器附带qt界面开发（附带源码）

whoarethenext

已于 2025-04-15 16:04:42 修改

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文章标签：服务器 qt 驱动开发 c++ 后端

于 2025-04-15 15:53:06 首次发布

本文链接：https://blog.youkuaiyun.com/m0_54069809/article/details/147250776

版权

本章是入门章节，讲解如何实现一个附带界面的服务器，后续会完善与优化

使用qt编译libevent
源码
演示视频
qt的一些知识

1.主要功能有登录界面
2.基于libevent实现的服务器的业务功能

使用qt编译libevent

下载这个，其他版本也可以
主要是github上下载，可能有点卡
链接: link
在这里插入图片描述

编译流程
1.打开qt然后点下面的红框

2.选cmakelist

3.选编译器
4.最后一步编译

5.编译成功后库的位置

最后编译成功后可以丢到/usr/bin里也可以丢到自己的写的程序的目录下

源码

源码结构如下
在这里插入图片描述
下面是libeventuse.cpp

#include "libeventuse.h"
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <signal.h>
#ifndef _WIN32
#include <netinet/in.h>
# ifdef _XOPEN_SOURCE_EXTENDED
#  include <arpa/inet.h>
# endif
#include <sys/socket.h>
#endif

#include <event2/bufferevent.h>
#include <event2/buffer.h>
#include <event2/listener.h>
#include <event2/util.h>
#include <event2/event.h>
#include"qdebug.h"


static const char MESSAGE[] = "Hello, World!\n";

static const unsigned short PORT = 9995;

static void listener_cb(struct evconnlistener *, evutil_socket_t,
    struct sockaddr *, int socklen, void *);
static void conn_writecb(struct bufferevent *, void *);
static void conn_eventcb(struct bufferevent *, short, void *);
static void signal_cb(evutil_socket_t, short, void *);




int main3()
{
    struct event_base *base;
    struct evconnlistener *listener;
    struct event *signal_event;

    struct sockaddr_in sin = {0};

    base = event_base_new();//初始化
    if (!base) {
        fprintf(stderr, "Could not initialize libevent!\n");
        return 1;
    }

    sin.sin_family = AF_INET;
    sin.sin_port = htons(PORT);

    listener = evconnlistener_new_bind(base, listener_cb, (void *)base,
        LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE, -1,
        (struct sockaddr*)&sin,
        sizeof(sin));//事件监听

    if (!listener) {
        fprintf(stderr, "Could not create a listener!\n");
        return 1;
    }

    signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base);//信号事件

    if (!signal_event || event_add(signal_event, NULL)<0) {
        fprintf(stderr, "Could not create/add a signal event!\n");
        return 1;
    }

    event_base_dispatch(base);//启动

    evconnlistener_free(listener);
    event_free(signal_event);
    event_base_free(base);

    printf("done\n");
    return 0;
}

static void
listener_cb(struct evconnlistener *listener, evutil_socket_t fd,
    struct sockaddr *sa, int socklen, void *user_data)
{
    struct event_base *base = static_cast<event_base*>(user_data);
    struct bufferevent *bev;

    bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
    if (!bev) {
        fprintf(stderr, "Error constructing bufferevent!");
        event_base_loopbreak(base);
        return;
    }
    bufferevent_setcb(bev, NULL, conn_writecb, conn_eventcb, NULL);
    bufferevent_enable(bev, EV_WRITE);
    bufferevent_disable(bev, EV_READ);

    bufferevent_write(bev, MESSAGE, strlen(MESSAGE));
}

static void
conn_writecb(struct bufferevent *bev, void *user_data)
{
    struct evbuffer *output = bufferevent_get_output(bev);
    if (evbuffer_get_length(output) == 0) {
        printf("flushed answer\n");
        bufferevent_free(bev);
    }
}

static void
conn_eventcb(struct bufferevent *bev, short events, void *user_data)
{
    if (events & BEV_EVENT_EOF) {
        printf("Connection closed.\n");
    } else if (events & BEV_EVENT_ERROR) {
        printf("Got an error on the connection: %s\n",
            strerror(errno));/*XXX win32*/
    }
    /* None of the other events can happen here, since we haven't enabled
     * timeouts */
    bufferevent_free(bev);
}

static void
signal_cb(evutil_socket_t sig, short events, void *user_data)
{
    struct event_base *base = static_cast<event_base*>(user_data);
    struct timeval delay = { 2, 0 };

    printf("Caught an interrupt signal; exiting cleanly in two seconds.\n");

    event_base_loopexit(base, &delay);
}
libeventuse::libeventuse()
{
    main3();
}

下面是mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "ui_form.h"
#include"QString"
#include"qdebug.h"
#include"qmessagebox.h"
#include"libeventuse.h"


#include <QMutex>
#include <QTime>
#include <QWidget>



WorkThread::WorkThread(QObject *parent) : QThread(parent) {}

void WorkThread::run() {  // 必须实现 run()
libeventuse tmp;
emit this->server_finish();
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{

    ui->setupUi(this);
   login_win=new Form;
   workthread=new WorkThread;
   login_win->hide();//登录窗口打开
   workthread->start();

   connect(this->workthread,&WorkThread::server_finish,[=](){
            qDebug()<<"服务器关闭";
   });
   connect(this->workthread,&WorkThread::finished,this->workthread,&QObject::deleteLater);

   connect(this->login_win,&Form::back,[=](){//槽函数
       this->show();//返回登录界面
       this->login_win->hide();//主执行界面关闭
   });



}

MainWindow::~MainWindow()
{
    delete login_win;
    delete ui;
}

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

}

Form::~Form()
{

    delete ui;
}

void MainWindow::on_pushButton_clicked()
{
    QString RootName=ui->rootName->text();
    QString Password=ui->password->text();
    if(RootName.size()==0)
    {
       QMessageBox::information(this, tr("提示"), tr("用户名没有输入"));
       return ;
    }
    else if(RootName.size()==0)
    {
        QMessageBox::information(this, tr("提示"), tr("密码没有输入"));
    }
    if(RootName=="i"&&Password=="1")//验证用户和密码
    {
        qDebug()<<RootName<<Password;
        login_win->show();//主执行界面打开
        this->hide();//登录界面关闭
    }
    else
    {
          QMessageBox::information(this, tr("提示"), tr("用户或密码输入错误"));
    }

}

void Form::on_pushButton_clicked()
{
    emit this->back();//发送信号
}

void MainWindow::on_pushButton_2_clicked()
{

}

下面是libeventuse.h

#ifndef LIBEVENTUSE_H
#define LIBEVENTUSE_H
class libeventuse
{
public:
    libeventuse();
};

#endif // LIBEVENTUSE_H

下面是mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
namespace Ui {
class Form;
}

class Form : public QWidget
{
    Q_OBJECT

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

private slots:
    void on_pushButton_clicked();
signals:
    void back();
private:
    Ui::Form *ui;
};


#include <QThread>
class WorkThread : public QThread {
    Q_OBJECT  // 必须添加！！！
public:
    explicit WorkThread(QObject *parent = nullptr);
protected:
    void run() override;  // 虚函数声明
signals:
void WorkThread_signal(int b);//自定义的信号
void server_finish();
};


namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
   Form* login_win=nullptr;
   WorkThread*workthread=nullptr;
private slots:
   void on_pushButton_clicked();
   void on_pushButton_2_clicked();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H