libevent服务器附带qt界面开发（附带源码）

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 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 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

pro文件的配置

演示视频

20250415_153450

我视频第一部分展示了如何在qt创建窗口 视频第二部分展示了客户端连接到服务器后会接收到hello world 视频等审核过了我再放上来 审核没过我就发效果图

qt的一些知识

1.信号的格式 signals: void WorkThread_signal(int b);//自定义的信号 2.注意事项，需要分写入Q_OBJECT才能这么定义 3.信号发送使用 emit 发送 4.使用connect槽函数来绑定信号要处理的逻辑