• 日期: 2028-01-05
  • 标签: 常规

C语言实现基于Socket和SQLite的智能家居状态建议系统

本文将介绍如何使用C语言、Socket编程和SQLite数据库，构建一个简单的智能家居状态建议系统。该系统可以接收客户端发送的用户ID，查询数据库获取设备状态，并根据预设规则生成建议反馈给客户端。

服务器端代码c#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/socket.h>#include <sys/select.h>#include <arpa/inet.h>#include <sqlite3.h>#include <netinet/in.h>

#define MAX_BUFFER_SIZE 1024

typedef struct { int uid; char device_name[10]; char device_state[10]; char value[10]; char mode[10];} Status;

typedef struct { int sockfd; struct sockaddr_in client_addr; socklen_t client_addr_len; sqlite3 *db;} ServerContext;

void handleClientRequest(ServerContext *context) { char buffer[MAX_BUFFER_SIZE]; int userid;

// 接收客户端发送的userid    ssize_t recvSize = recv(context->sockfd, &userid, sizeof(int), 0);

if (recvSize == -1) {        perror('userid接受失败\nrecv');        return;    } else if (recvSize == 0) {        perror('客户端已关闭连接');        return;    } else if (recvSize != sizeof(int)) {        perror('接收到的字节数不正确');        return;    }    userid = ntohl(userid); // 将网络字节序转换为主机字节序    printf('客户端已连接\n');    printf('userid:%d',userid);    // 查询数据库获取设备状态信息    char sql[100];    snprintf(sql, sizeof(sql), 'SELECT * FROM Status WHERE uid = %d', userid);    sqlite3_stmt *stmt;    int rc = sqlite3_prepare_v2(context->db, sql, -1, &stmt, NULL);    if (rc != SQLITE_OK) {        fprintf(stderr, '无法执行的语句: %s\n', sqlite3_errmsg(context->db));        return;    }

Status status;    memset(&status, 0, sizeof(Status)); // 清空status结构体

// 处理查询结果为空的情况    int result = sqlite3_step(stmt);     if (result == SQLITE_ROW) {        status.uid = sqlite3_column_int(stmt, 0);        strncpy(status.device_name, sqlite3_column_text(stmt, 1), sizeof(status.device_name)-1);        strncpy(status.device_state, sqlite3_column_text(stmt, 2), sizeof(status.device_state)-1);        strncpy(status.value, sqlite3_column_text(stmt, 3), sizeof(status.value)-1);        strncpy(status.mode, sqlite3_column_text(stmt, 4), sizeof(status.mode)-1);    } else if (result == SQLITE_DONE) {        fprintf(stderr, 'No data found for user %d\n', userid);        sqlite3_finalize(stmt);

    // 处理查询结果为空的情况，例如返回默认建议        snprintf(buffer, sizeof(buffer), '没有找到用户 %d 的设备信息', userid);        send(context->sockfd, buffer, strlen(buffer), 0);        return;    } else {        fprintf(stderr, '数据库查询出错: %s\n', sqlite3_errmsg(context->db));        sqlite3_finalize(stmt);        return;    }        sqlite3_finalize(stmt);

// 分析设备状态并生成建议    char suggestion[MAX_BUFFER_SIZE];    if (strcmp(status.device_name, '空调') == 0) {        int temperature = atoi(status.value);        if (temperature < 24) {            snprintf(suggestion, sizeof(suggestion), '空调温度过低，建议提高温度至26℃');        } else {            snprintf(suggestion, sizeof(suggestion), '空调温度正常');        }    } else if (strcmp(status.device_name, '加湿器') == 0) {        int humidity = atoi(status.value);        if (humidity < 40 || humidity > 70) {            snprintf(suggestion, sizeof(suggestion), '加湿器湿度过高或过低，建议调整加湿器湿度');        } else {            snprintf(suggestion, sizeof(suggestion), '加湿器湿度正常');        }    } else {        snprintf(suggestion, sizeof(suggestion), '设备状态未知');    }

// 向客户端发送建议    ssize_t sendSize = send(context->sockfd, suggestion, strlen(suggestion), 0);    if (sendSize == -1) {        perror('发送失败\nsend');        return;    }    printf('%s',suggestion);}

int main() { printf('正在连接中...\n'); int sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd == -1) { perror('连接失败\nsocket'); return 1; }

struct sockaddr_in server_addr;    server_addr.sin_family = AF_INET;    server_addr.sin_addr.s_addr = INADDR_ANY;    server_addr.sin_port = htons(12345);

if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {        perror('连接失败\nbind');        close(sockfd);        return 1;    }

if (listen(sockfd, 5) == -1) {        perror('连接失败\nlisten');        close(sockfd);        return 1;    }

sqlite3 *db;    int rc = sqlite3_open('/mnt/g/Qt/Client/Smarthome_Client/database/database.db', &db);    if (rc != SQLITE_OK) {        fprintf(stderr, '数据库打开失败: %s\n', sqlite3_errmsg(db));        return 1;    }

ServerContext context;    context.sockfd = sockfd;    context.client_addr_len = sizeof(context.client_addr);    context.db = db;

fd_set readfds;    int maxfd = sockfd;

while (1) {        FD_ZERO(&readfds);        FD_SET(sockfd, &readfds);

    int activity = select(maxfd + 1, &readfds, NULL, NULL, NULL);        if (activity == -1) {            perror('select');            break;        }

    if (FD_ISSET(sockfd, &readfds)) {            int clientSockfd = accept(sockfd, (struct sockaddr *)&context.client_addr, &context.client_addr_len);            if (clientSockfd == -1) {                perror('套接字接收失败\naccept');                break;            }

        context.sockfd = clientSockfd;            handleClientRequest(&context);

        close(clientSockfd);        }    }    sqlite3_close(db);    close(sockfd);    printf('服务器已关闭\n');

return 0;}

客户端代码cpp#include 'procession.h'#include 'ui_procession.h'#include #include

Procession::Procession(int userid,QWidget *parent) : QWidget(parent), ui(new Ui::Procession), userid(userid){ ui->setupUi(this); processionWidget(); m_socket = new QTcpSocket(this); //connect(ui->connectBtn, &QPushButton::clicked, this, &Procession::on_connectBtn_clicked); connect(m_socket, &QTcpSocket::readyRead, this, &Procession::readyRead); connect(m_socket, &QTcpSocket::connected, this, &Procession::connected); connect(m_socket, &QTcpSocket::disconnected,this,&Procession::disconnected); connect(m_socket, QOverloadQAbstractSocket::SocketError::of(&QTcpSocket::error), this, &Procession::displayError);}

Procession::~Procession(){ delete ui;}

void Procession::processionWidget(){ setWindowTitle('服务器通信'); setAutoFillBackground(true); QPalette palette=this->palette(); QPixmap pixmap(':/user/image/image/net.jpg'); palette.setBrush(QPalette::Window, QBrush(pixmap)); setPalette(palette); setFixedSize(600,400);}

void Procession::connected(){ ui->message->append('连接成功'); QByteArray block; QDataStream out(&block, QIODevice::WriteOnly); out << static_cast(this->userid); if (m_socket->write(block) == -1) { ui->message->append('发送userid失败'); m_socket->close(); }}

void Procession::disconnected(){ ui->message->append('连接失败'); m_socket->close();}

void Procession::readyRead(){ QByteArray data = m_socket->readAll(); if (data.isEmpty()) { ui->message->append('读取的数据为空'); return; } // 解析服务器返回的数据 QDataStream in(&data, QIODevice::ReadOnly); QString suggestion; in >> suggestion; // 使用重载的 >> 运算符来读取数据 if (in.status() != QDataStream::Ok) { ui->message->append('解析服务器返回的数据失败'); return; } ui->message->append(suggestion); m_socket->close();}

void Procession::displayError(QAbstractSocket::SocketError error){ QString errorMessage; switch (error) { case QAbstractSocket::ConnectionRefusedError: errorMessage = '连接被拒绝'; break; case QAbstractSocket::RemoteHostClosedError: errorMessage = '远程主机关闭'; break; case QAbstractSocket::HostNotFoundError: errorMessage = '未找到主机'; break; case QAbstractSocket::SocketTimeoutError: errorMessage = '连接超时'; break; case QAbstractSocket::NetworkError: errorMessage = '网络错误'; break; default: errorMessage = '未知错误'; break; } ui->message->append('连接失败：' + errorMessage);}

void Procession::on_connectBtn_clicked(){ if (m_socket->state() == QAbstractSocket::ConnectedState) { m_socket->disconnectFromHost(); // 先关闭套接字 qDebug() << '1'; }

ui->message->append('已经连接上服务器');    QString ip = ui->IP->text();    QString port = ui->port->text();

if (ip.isEmpty() || port.isEmpty()) {        ui->message->clear();        ui->message->append('请输入有效的IP地址和端口号');        return;    }

ui->message->clear();    ui->message->append('正在连接中...');    m_socket->connectToHost(ip, static_cast<quint16>(ui->port->text().toInt()));}

#ifndef PROCESSION_H#define PROCESSION_H

#include #include #include #include #include

namespace Ui {class Procession;}

class Procession : public QWidget{ Q_OBJECT

public: explicit Procession(int userid,QWidget *parent = nullptr); ~Procession(); void processionWidget();

private slots: //void on_pushButton_clicked(); void connected(); void disconnected(); void readyRead(); void displayError(QAbstractSocket::SocketError error);

void on_connectBtn_clicked();

private: Ui::Procession ui; int userid; QTcpSocket m_socket;};

#endif // PROCESSION_H

代码说明

  1. 服务器端使用C语言编写，客户端使用Qt框架编写。2. 服务器端使用Socket编程监听客户端连接请求，并使用select函数实现多路复用，处理多个客户端连接。3. 服务器端使用SQLite数据库存储设备状态信息，并根据客户端发送的用户ID查询数据库获取对应设备状态。4. 服务器端根据预设规则分析设备状态，并生成建议反馈给客户端。5. 客户端连接服务器后，发送用户ID给服务器，并接收服务器返回的建议信息。

运行结果

  1. 编译并运行服务器端程序。2. 编译并运行客户端程序，输入服务器IP地址和端口号，点击连接按钮。3. 客户端成功连接服务器后，会发送用户ID给服务器，并接收服务器返回的建议信息。

总结

本文介绍了如何使用C语言、Socket编程和SQLite数据库构建一个简单的智能家居状态建议系统。该系统可以根据预设规则分析设备状态，并生成建议反馈给用户，为用户提供更智能的家居体验。

C语言实现基于Socket和SQLite的智能家居状态建议系统

原文地址: https://www.cveoy.top/t/topic/fCAf 著作权归作者所有。请勿转载和采集!

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